ATI Crossfire or Nvidia SLI support [Archive]

ray_uk

Feb 4, 2008, 09:00 AM

Tallest Skil

Feb 4, 2008, 09:11 AM

For the last time, as I've personally made two threads on this subject. NO SLI OR CROSSFIRE in OS X. The people who use either of them represent around 2% of the entire market, and Apple couldn't care less about gaming, anyway. On the old Mac Pro, it was found to work somewhat in Windows, but you're not getting two 8800 GT to work together in OS X.

To remedy this situation, I'm getting two 8800 GT for my Mac Pro anyway and hooking up one monitor to each. That way I have the power of an entire card behind each monitor; something that SLI and CrossFire can't do.

Oh, and I don't put an 's' on 8800 GT when it's plural because I don't want to mess up searches for specific models.

Edit: OP, congratulations on your first name.

TBi

Feb 4, 2008, 09:20 AM

From what I have heard the current Mac Pro can support either 2 x 8800GT's or 2 x 3870's as far as the energy requirements go, however, within Leopard its not going to do either Crossfire or SLI, but will function as two individual graphic cards, note the 3870 is not officially supported in OSX, however under windows it is very likely that the two 3870's would support corssfire I believe due to current crossfire being implemented in drivers.

Both SLi and Crossfire and implemented in drivers. They are also limited by the drivers to only work on boards nVidia/ATi deem compatible. There is no hard physical limitation stopping a board with dual PCI-E 16x slots from doing either.

iansilv

Feb 4, 2008, 07:48 PM

TBi

Feb 4, 2008, 08:07 PM

I am not talking about them being supported now- I am talking about them being supported in the future. Sure, its not mainstream, but it is someting that , from a PR standpoint, would get apple some attention from gamers.

I don't think SLI will happen until nVidia support SLI on Intel. Imagine buying a Mac Pro and having SLI in OSX, but not in Windows. That would get a whole lot of people annoyed.

kabunaru

Feb 4, 2008, 09:00 PM

So, Crossfire is more "possible" on a Mac Pro than SLI?

ekwipt

Feb 5, 2008, 01:18 AM

more possible yes because it is on a intel board, i doubt that we'll ever get crossfire going in osx. nvidia doesn't do sli on intel boards. except maybe for skulltrail

ray_uk

Feb 5, 2008, 02:20 AM

True, I am however baseing this on the asumption that since Crossfire is supported on the Intel P35, X38 and X48 chipsets it makes it highly likely to work on the current Mac Pro whose motherboard uses Intel 5400 chipset which is similar chipset to that of the Skulltrail boards due out soon, which definitely supports crossfire and probably SLI to.

Both SLi and Crossfire and implemented in drivers. They are also limited by the drivers to only work on boards nVidia/ATi deem compatible. There is no hard physical limitation stopping a board with dual PCI-E 16x slots from doing either.

newtech

Feb 5, 2008, 02:24 AM

True, I am however baseing this on the asumption that since Crossfire is supported on the Intel P35, X38 and X48 chipsets it makes it highly likely to work on the current Mac Pro whose motherboard uses Intel 5400 chipset which is similar chipset to that of the Skulltrail boards due out soon, which definitely supports crossfire and probably SLI to.

NO, Skulltrail has nVidia chips that the Mac Pro motherboard does not have, so no SLI. P35, X38 and X48 chipsets are in a different class from 5400B

Bastich

Feb 5, 2008, 02:41 AM

Sure, its not mainstream, but it is someting that , from a PR standpoint, would get apple some attention from gamers.

Having some GAMES would get attention from gamers.

B)

TBi

Feb 5, 2008, 04:30 AM

NO, Skulltrail has nVidia chips that the Mac Pro motherboard does not have, so no SLI. P35, X38 and X48 chipsets are in a different class from 5400B

The reason SLI doesn't work on intel motherboards is the same reason OSX doesn't install on any X86 machine.

There is no hardware or technical reason why SLI or Crossfire can't run on these chip sets. There is no hardware or technical reason why SLI can't run on ATi chipsets, or for crossfire to run on nVidia chipsets.

All the work for SLI/Crossfire is done in the driver. The driver artificially limits what chipsets it "supports".

ray_uk

Feb 5, 2008, 05:09 AM

Yeah, the driver does determine which chipset it runs, on and in this instance as I had mentioned its the Intel 5400 chipset same as the one the Skulltrail motherboard uses which does support crossfire and just so happens to be the same chipset the the Mac Pro uses.

All I'm saying is the likelyhood of crossfire working under windows is very high.

Mercuric Oxide

Feb 5, 2008, 05:36 AM

What about the 300W PCI total? Is this circumvented with other connectors to the main PSU?

diamond.g

Feb 5, 2008, 07:17 AM

What about the 300W PCI total? Is this circumvented with other connectors to the main PSU?

As long as the PSU can take the power draw you can connect as many cards as you want. All you need is some 4-pin molex to 8 (or 6)-pin PCIe connectors.

ray_uk

Feb 6, 2008, 01:56 AM

:D

The power consumption of a 8800GT is somewhere in the upper 130 Watts region so the Mac Pro should manage with two.

:D

Tallest Skil

Feb 6, 2008, 07:22 AM

:D

The power consumption of a 8800GT is somewhere in the upper 130 Watts region so the Mac Pro should manage with two.

:D

110, actually, so we should be good.

jatkins123

Feb 6, 2008, 07:50 AM

ok so can i get an answer for this...

I have a macpro coming. standard config with extra ram HD's blah blah blah and 1 8800gt...i do my work in OSX and i accept that 2 8800gt's will do nothing other than let me run extra monitors...however, i intend to do some gaming in windows vista and I want to know if this will benefit me there if i run it in SLI mode??

thanks

diamond.g

Feb 6, 2008, 08:43 AM

jatkins123

Feb 6, 2008, 08:48 AM

You can only do that with hacked (read: unsupported) drivers. But yes you can get SLI working in Windows with 2 8800GT cards.

thanks for the quick reply!! would you be able to tell me where i might find out how to do this? and if i get these drivers it wont effect the cards working in OSX right?

sorry im a bit clueless

diamond.g

Feb 6, 2008, 09:05 AM

thanks for the quick reply!! would you be able to tell me where i might find out how to do this? and if i get these drivers it wont effect the cards working in OSX right?

sorry im a bit clueless

After doing some snooping, it is more difficult than I realized. Plus no one is sure that the GF8 series will even work with the hacked drivers. Supposedly there is a way to get a more up to date inf that should include the GF8 cards. Here is the long thread (http://www.xtremesystems.org/forums/showthread.php?t=106212&highlight=crossfire+nvidia+motherboard).

ma2ha3

Feb 6, 2008, 09:16 AM

NO. stay off apple if you are a gamer.

Fuzzbear

Feb 6, 2008, 09:33 AM

You can only do that with hacked (read: unsupported) drivers. But yes you can get SLI working in Windows with 2 8800GT cards.
Id imagine you would have to make sure the SLI connector was on the cards?

for SLI to work on Wintel's the cards are physically bridged together with an internal connector that typically comes with a Motherboard.

http://www.xbitlabs.com/images/mainboards/asus-a8n32-sli-deluxe/a8n32sli_mioconnector_sm.jpg

Kosh66

Feb 6, 2008, 10:35 AM

Id imagine you would have to make sure the SLI connector was on the cards?

for SLI to work on Wintel's the cards are physically bridged together with an internal connector that typically comes with a Motherboard.

He'll need a flexible bridge, likely. Those that have got this working on the first generation of Mac Pros used a flexible bridge, I believe.

As well, wouldn't pro apps like Maya and Cinema 4 and Final Cut Pro's Color benefit from SLI. I mean we always look at the games part, which interests me, but what's good for games is often good for the pro apps, right? So then it would be of interest to Apple to support SLI or Crossfire.

jasonvp

Feb 6, 2008, 11:12 AM

but what's good for games is often good for the pro apps, right? So then it would be of interest to Apple to support SLI or Crossfire.

Not in the least, right now. There has to be application-level support as well as OS-level support in order to fully take advantage of SLI. Not quite as sure about Crossfire.

Either way, the Pro apps will need to support SLI. Not just the operating system.

And remember: as soon as you enable SLI, you lose all but 1 monitor. There is no multi-monitor support for SLI from nVidia.

jas

TBi

Feb 6, 2008, 11:24 AM

Not in the least, right now. There has to be application-level support as well as OS-level support in order to fully take advantage of SLI. Not quite as sure about Crossfire.

Either way, the Pro apps will need to support SLI. Not just the operating system.

And remember: as soon as you enable SLI, you lose all but 1 monitor. There is no multi-monitor support for SLI from nVidia.

jas

Application level support? Where are you getting that from? SLI is driver enabled and driven. The 'application' just sees a faster graphics card, it doesn't need to know anything about what the graphics card is because it only talks to the driver and the driver can lie all it wants.

Well it seems SLI is single monitor only which does kind of suck.

As for 1 monitor, i can't verify this but i'm sure it isn't true. You lose the ability to run a monitor from the second card but both outputs on the main card should still work.

diamond.g

Feb 6, 2008, 11:30 AM

jasonvp

Feb 6, 2008, 11:31 AM

Application level support? Where are you getting that from? SLI is driver enabled and driven. The 'application' just sees a faster graphics card, it doesn't need to know anything about what the graphics card is because it only talks to the driver and the driver can lie all it wants.

Well it seems SLI is single monitor only which does kind of suck.

As for 1 monitor, i can't verify this but i'm sure it isn't true. You lose the ability to run a monitor from the second card but both outputs on the main card should still work.

OK, I have DIRECT SLI experience, and a lot of it. :-) I use it quite heavily on my Windows gaming machine at home.

1. SLI is OS-level AND application-level supported. If the application (in this case, the game) isn't aware of more than 1 card, it won't be used. Period. The OS doesn't "lie" to the application and tell it, "Trust me.. there's only one card. Really." That's not the way SLI works. The game MUST BE written to support SLI or the 2nd card just won't be used.

2. When SLI is enabled, ALL OUTPUT goes to monitor 1. No ifs, no ands, no buts. Multi-monitor support IS NOT THERE. I've tried it many times, in many different monitor configurations. nVidia has said it's not there, and it's not there. The idea is: take all of the processing from the two cards and pump it through one monitor.

jas

kabunaru

Feb 6, 2008, 04:45 PM

[QUOTE=TBi;4907481]

Well it seems SLI is single monitor only which does kind of suck.

[QUOTE]

Yeah, Crossfire is better than SLI generally.

Fuzzbear

Feb 6, 2008, 05:35 PM

2. When SLI is enabled, ALL OUTPUT goes to monitor 1. No ifs, no ands, no buts. Multi-monitor support IS NOT THERE. I've tried it many times, in many different monitor configurations. nVidia has said it's not there, and it's not there. The idea is: take all of the processing from the two cards and pump it through one monitor.

jas

yeah actually the way around that is to put in a 3rd Non Nvidia video card. That way the Nvidia Drivers don't shut it down on you when you enable SLI. You will still only be able to use one Monitor in your game... but when your not gaming both monitors will be active as long as one in plugged into the non Nvidia card.

m1stake

Feb 6, 2008, 05:42 PM

I couldn't vouch for the 1000 or 2000 series, but I know that the 3000 series from ATI supports dual monitors while using multiple graphics cards.

The 3870 x2 was doing it with no issues in a review, and I hear the entire line can do it.

jasonvp

Feb 6, 2008, 05:44 PM

yeah actually the way around that is to put in a 3rd Non Nvidia video card. That way the Nvidia Drivers don't shut it down on you when you enable SLI. You will still only be able to use one Monitor in your game... but when your not gaming both monitors will be active as long as one in plugged into the non Nvidia card.

That's correct. The other solution is to keep all the monitors attached, as usual. When it's time to game, "detach" all other monitors (assuming Windows), and then enable SLI. When gaming is over, disable SLI, and then "re-attach" the other monitors.

That's what I was doing when I was running multiple monitors on my Windows box.

jas

jasonvp

Feb 6, 2008, 05:44 PM

The 3870 x2 was doing it with no issues in a review, and I hear the entire line can do it.

But is this with Crossfire enabled?

jas

Tallest Skil

Feb 6, 2008, 06:39 PM

[QUOTE=TBi;4907481]
Well it seems SLI is single monitor only which does kind of suck.[QUOTE]

Thus my desire to have two 8800 GT, NOT SLI them, and plug one of my monitors into each, so as to have a pseudo-SLI over a 3840x1200 screen. Seems like the better option for users who want the (gaming?) power of multiple cards with the screen size to do what they desire.

Heh. Can you imagine this idea being put into practice by flight simulation enthusiasts?! They get a full-size PC tower-you know, the ones with 12 PCI slots-and run a cheapish graphics card off of each to get their full surround window feel...

Now imagine that with 12 8800 GTs. Can you say 3,000 watt power supply? :rolleyes:

Edit: I can't get the stupid quote quotingness to work right, but you get the picture...

Akula971

Feb 6, 2008, 07:00 PM

NO. stay off apple if you are a gamer.

You must mean a "serious" gamer? Yes? No? I've read that some folks have been known to boot into windows and play games like Bioshock, Crysis, Halflife 2 DoD, etc on Imac's and MacPro's. Hell I've even seen video's on you tube. So I guess you can do it.
I'm watching these threads with great interest you see as I'm in the position of having moved over to OSX from XP/Vista by virtue of a MacMini, which you may appreciate is not really suitable to play anything other than Rise of Nations and Solitaire. I need a more powerful Mac. My windows box (Northwood P4, AGP 1800XT card) is now long in the tooth. So I'm faced with either buying a MacPro to do just "Everything" or getting an Imac AND a new windows box for games. Oooh the confusion, the conflict, the cash? My plan is a MacPro with a 8800GT or I've read that you put some other "windows" graphics cards in that will only be seen in bootcamp? and stick with the stock 2600 card for OSX.

What do you folks think? Anybody have direct experience?

Fuzzbear

Feb 6, 2008, 07:07 PM

You must mean a "serious" gamer? Yes? No? I've read that some folks have been known to boot into windows and play games like Bioshock, Crysis, Halflife 2 DoD, etc on Imac's and MacPro's. Hell I've even seen video's on you tube. So I guess you can do it.
I'm watching these threads with great interest you see as I'm in the position of having moved over to OSX from XP/Vista by virtue of a MacMini, which you may appreciate is not really suitable to play anything other than Rise of Nations and Solitaire. I need a more powerful Mac. My windows box (Northwood P4, AGP 1800XT card) is now long in the tooth. So I'm faced with either buying a MacPro to do just "Everything" or getting an Imac AND a new windows box for games. Oooh the confusion, the conflict, the cash? My plan is a MacPro with a 8800GT or I've read that you put some other "windows" graphics cards in that will only be seen in bootcamp? and stick with the stock 2600 card for OSX.

What do you folks think? Anybody have direct experience?

Im in a slightly better boat. Im going to be getting a Macbook Pro for work, and just so I can get used to using OSX. Im keeping my main windows PC though for gaming...luckily its a custom DIY machine so It shouldn't be TOO difficult to throw some money into it now and again to keep it up to date.

Can you update your PC at all so its not so "Long In The tooth?" or is it a retail box?

Umbongo

Feb 6, 2008, 10:58 PM

He'll need a flexible bridge, likely. Those that have got this working on the first generation of Mac Pros used a flexible bridge, I believe.

As well, wouldn't pro apps like Maya and Cinema 4 and Final Cut Pro's Color benefit from SLI. I mean we always look at the games part, which interests me, but what's good for games is often good for the pro apps, right? So then it would be of interest to Apple to support SLI or Crossfire.

Maya benefits, by about 30-35% from the various benchmarks I've seen. However even the cheapest quadro fx cards would offer more performance than SLI'd 8800GTs and would surely be a much better way for Apple to go on an official platform.

diamond.g

Feb 7, 2008, 07:54 AM

Maya benefits, by about 30-35% from the various benchmarks I've seen. However even the cheapest quadro fx cards would offer more performance than SLI'd 8800GTs and would surely be a much better way for Apple to go on an official platform.

Eh, the cheaper quadros are based on different (read: slower) cores. The G92 would be faster. Only the G80 would have the ability to match it in performance.

Umbongo

Feb 7, 2008, 09:18 AM

Eh, the cheaper quadros are based on different (read: slower) cores. The G92 would be faster. Only the G80 would have the ability to match it in performance.

No, the Quadro drivers are far superior, which is where the performance comes from.

Fuzzbear

Feb 7, 2008, 11:21 AM

as a mac newbie, but a very experienced PC DIY'er is there some physical hardware different on the OSX branded ATI/Nvidia Cards? Or is it just flashed with a different eprom?

anyone?

TBi

Feb 7, 2008, 11:28 AM

Eh, the cheaper quadros are based on different (read: slower) cores. The G92 would be faster. Only the G80 would have the ability to match it in performance.

The quadro uses the same chipset as the equivalent geforce. The old models based on the G80 and the newer ones will probably be based on the 8800GTS chipset.

No, the Quadro drivers are far superior, which is where the performance comes from.

The quadro drivers just unlock GPU functionality that is hidden on the standard geforce. So it can do some things faster in hardware. However quadro drivers are usually slower than geforce drivers in games because they are not optimised for them.

as a mac newbie, but a very experienced PC DIY'er is there some physical hardware different on the OSX branded ATI/Nvidia Cards? Or is it just flashed with a different eprom?

anyone?

Just a different eeprom, although on some cards the eeprom is a different size.

Fuzzbear

Feb 7, 2008, 11:30 AM

Just a different eeprom, although on some cards the eeprom is a different size.

So has any enterprising little hackers come up with a way to flash a standard retail card to work in apple hardware?

TBi

Feb 7, 2008, 11:31 AM

So has any enterprising little hackers come up with a way to flash a standard retail card to work in apple hardware?

I've seen it done on older cards, it should be possible on newer ones too. However not many people take the risk because a dead card is worthless.

Fuzzbear

Feb 7, 2008, 11:34 AM

I've seen it done on older cards, it should be possible on newer ones too. However not many people take the risk because a dead card is worthless.

but a dead retail card can be returned to the store :D

TBi

Feb 7, 2008, 11:58 AM

but a dead retail card can be returned to the store :D

Only if they don't bother to look at it to see the easily visible damage you've done.

EDIT: Just so that makes more sense, the way i've seen it done is someone removes the smaller retail EEPROM and solders on a bigger EEPROM which can then be flashed with apple's firmware. This does visible damage to the card.

Also i don't agree with this stance. It drives prices up for everyone, you break it you bought it.

It's ok if the card dies from a simple bios transplant as it shouldn't

Fuzzbear

Feb 7, 2008, 04:16 PM

Only if they don't bother to look at it to see the easily visible damage you've done.

EDIT: Just so that makes more sense, the way i've seen it done is someone removes the smaller retail EEPROM and solders on a bigger EEPROM which can then be flashed with apple's firmware. This does visible damage to the card.

Also i don't agree with this stance. It drives prices up for everyone, you break it you bought it.

It's ok if the card dies from a simple bios transplant as it shouldn't oh you made it sound like they were just reflashing the existing eprom, not removing it and replacing it.

TBi

Feb 7, 2008, 08:07 PM

oh you made it sound like they were just reflashing the existing eprom, not removing it and replacing it.

Some are that easy but mostof the time it isn't. I should have made that clear in my first post.

Mercuric Oxide

Feb 8, 2008, 12:11 AM

The 8800GT's shipping with the new Mac Pro have SLI connectors...

I don't know if the mobo supports it though for Windows

TBi

Feb 8, 2008, 04:37 AM

The 8800GT's shipping with the new Mac Pro have SLI connectors...

I don't know if the mobo supports it though for Windows

You don't need motherboard support, you need driver support. All SLI/Crossfire is done in software (except for the SLI/Xfire bridges but they are on the graphics cards).

diamond.g

Feb 8, 2008, 06:45 AM

The quadro uses the same chipset as the equivalent geforce. The old models based on the G80 and the newer ones will probably be based on the 8800GTS chipset.

Sorta. The most recent set of Quadros uses the G80(GL). The next set use G71(GL). There isn't a G92(GL) yet. So the 8800GT (clocked higher) really would be faster.

TBi

Feb 8, 2008, 06:53 AM

Sorta. The most recent set of Quadros uses the G80(GL). The next set use G71(GL). There isn't a G92(GL) yet. So the 8800GT (clocked higher) really would be faster.

You're right, i was mainly pointing out that the hardware is generally identical and the drivers just enable disabled parts of the chip.

Mercuric Oxide

Feb 8, 2008, 12:25 PM

You don't need motherboard support, you need driver support. All SLI/Crossfire is done in software (except for the SLI/Xfire bridges but they are on the graphics cards).

But SLI/XFire won't work on boards that Nvidia/ATi don't support for that, so technically, yes it's the drivers - which the companies may not support on our motherboard.

TBi

Feb 8, 2008, 01:13 PM

But SLI/XFire won't work on boards that Nvidia/ATi don't support for that, so technically, yes it's the drivers - which the companies may not support on our motherboard.

It would work if they took out those stupid artifical locks that stop you from doing it :)

Mercuric Oxide

Feb 8, 2008, 02:37 PM

It would work if they took out those stupid artifical locks that stop you from doing it :)

I agree. By artificially locking it, aren't they limiting their ultra high end solutions to like 10% of computer users? This may be why SLI/XFire isn't growing, not just because of price.

You would think that these greedy businesses would want to maximize sales...

diamond.g

Feb 8, 2008, 02:48 PM

I agree. By artificially locking it, aren't they limiting their ultra high end solutions to like 10% of computer users? This may be why SLI/XFire isn't growing, not just because of price.

You would think that these greedy businesses would want to maximize sales...

They do want to maximise sales. That is how they got Intel to license the NV100 SB for the Skulltrail boards. Nvidia (and probably ATI) supposedly makes more money from motherboard chipsets than they do with video cards. The only cards with great margins are the higher end cards that very few people buy. The rush to the cheaper card isn't as lucrative. Getting an OEM (systembuilder) to user your mobo can rake in more money (sheer volume) than selling higher end video cards ever would.

Mercuric Oxide

Feb 8, 2008, 03:26 PM

Oh, ok. Thanks for the info

iansilv

Feb 9, 2008, 02:20 AM

diamond.g

Feb 9, 2008, 08:04 AM

I just want to see leopard support it for mac gaming. I know leopard could do a cleaner job of supporting sli than vista ever could.

BTW- hey Microsoft- good job on Vista- it made me buy my first mac!

Nvidia would have to let Apple use SLI without using Nvidia chipset. They didn't let Intel (who is far larger than Apple) use it without the NV100SB. Why would they let Apple use it?

If Apple were to hack their own drivers I think Nvidia would stop giving them driver support. Besides it isn't Vista's fault SLI was horrible, it is Nvidia's fault. MS doesn't write graphics drivers like Apple does.

It would be more likely to see Crossfire support. Since ATI is nicer about it than Nvidia. Of course games would still need to be SLI/Crossfire aware. Although that may not be the case if the X2/GX2 cards are used as they can show up as one card versus two.

chewietobbacca

Feb 10, 2008, 04:45 AM

I just want to see leopard support it for mac gaming. I know leopard could do a cleaner job of supporting sli than vista ever could.

BTW- hey Microsoft- good job on Vista- it made me buy my first mac!

Vista was not at fault about it at all - ATI and Nvidia dropped the ball badly on support for CF and SLI in Vista. Hell, their support in XP took forever to get going, and the GX2's quad-SLI was completely forgotten and shoved under the rug.

As far as sales go, motherboard chipsets DO NOT make more money for the companies. They're all relatively small departments - the big money maker for companies is in their mainstream cards. High end cards bring attention to the name but the mainstream is what most people buy and what drives profits.

As far as SLI/CF go, it's both a driver and a software thing. In truth, SLI does NOT require a chip. The Skulltrail has SLI enabled precisely because Intel bought the NV100BSB and thus Nvidia gets money for it - but the NV100SB is not required. Back in the day, people had hacked drivers to enable SLI on the 975X which did not have any nForce chip. CrossFire doesn't require any chip either as it's run quite well on both Intel and AMD chipsets.

Drivers have to unlock the card to work on the motherboard. Drivers also drive how well the card performs. But the software must also take advantage of multi-GPU's. For instance, F.E.A.R. scales really well with SLI/CF while some other games such as World in Conflict, not so much. It's how the game is written as well.

Also, for multi-monitor support: ATI has the advantage on this one as their upcoming CrossFireX supports not only 2-4 GPU's, but it also supports up to 8 monitors. There's a video on youtube of them running a demo with 8 monitors + Flight Sim X. Impressive to say the least :eek:

Good news is that multi-GPU support seems to be increasing. ATI released the 3870X2 recently and Nvidia is set to debut the 9800GX2 in early March. Also, ATI's next generation R700 is rumored to use multi-GPU approach as well.

Ploki

Feb 10, 2008, 06:18 AM

Tallest Skil

Feb 10, 2008, 07:34 AM

"With Mac Pro, you have the NVIDIA GeForce® 8800 GT. You can pack your Mac Pro with as many as four GeForce® 8800 GT graphics cards, each driving two independent displays for the ultimate in visual real-estate."
is that true?

NO. Is that that quote from the nVidia website? Yeah, they need to fix that before someone wastes a bunch of money on cards and fries their motherboard. You can only have two 8800 GT in your Mac Pro because of power restrictions and the fact that there are only two external power cables. Looks like they just changed 7300 to 8800...

diamond.g

Feb 10, 2008, 08:33 AM

As far as SLI/CF go, it's both a driver and a software thing. In truth, SLI does NOT require a chip. The Skulltrail has SLI enabled precisely because Intel bought the NV100BSB and thus Nvidia gets money for it - but the NV100SB is not required. Back in the day, people had hacked drivers to enable SLI on the 975X which did not have any nForce chip. CrossFire doesn't require any chip either as it's run quite well on both Intel and AMD chipsets.

Drivers have to unlock the card to work on the motherboard. Drivers also drive how well the card performs. But the software must also take advantage of multi-GPU's. For instance, F.E.A.R. scales really well with SLI/CF while some other games such as World in Conflict, not so much. It's how the game is written as well.

I have not found any successful driver hacks that allow the G8x/G9x to work without Nvidia chipsets. So it seems like they have somehow fixed the drivers. So for now to get the latest and greatest it does require a chip.

I guess I was mistaken on the mobo thing. I has seemed to recall Nvidia posting crazy profits due to the Nforce mobo's doing so well. Truthfully AMD chips pretty much were only worth it when running Nforce. You haven't seen the same level of pickup with Intel chips due to Intel having a pretty good chipset/mobo already. ATI/AMD has to get cranking on the chipset/mobo front.

Brianna

Feb 10, 2008, 08:34 AM

Both SLi and Crossfire and implemented in drivers. They are also limited by the drivers to only work on boards nVidia/ATi deem compatible. There is no hard physical limitation stopping a board with dual PCI-E 16x slots from doing either.

Actually there is a physical limitation. Something about a northbridge needs to be present, and Nvidia SLI MCP's. I've done a little research on this myself. Sorry to burst your bubble. :(

Umbongo

Feb 10, 2008, 09:41 AM

Actually there is a physical limitation. Something about a northbridge needs to be present, and Nvidia SLI MCP's. I've done a little research on this myself. Sorry to burst your bubble. :(

You only needed hacked drivers and the SLI bridge for 7 series cards I believe. Though I would think Nvidia either made it so their chips needed to be present with 8 series cards, or no one wants to create the hacked drivers anymore.

Brianna

Feb 10, 2008, 09:58 AM

If you look at, and read about the SkullTrail motherboard that intel is developing you'll notice PC gamers are completely going off the hook crazy because intel is using server FB-DIMM's for RAM rather than high performance gaming memory. (which is like 40% slower for gaming on a PC)
The other thing you'll notice is if you look at it closely - being that it has FB-DIMM's it is basically the same motherboard Apple is using now accept it has the Nvidia MCP's on it for SLI. Makes you wonder. :apple:

diamond.g

Feb 10, 2008, 10:32 AM

Brianna

Feb 10, 2008, 11:12 AM

Wonder what?

lol, if a variation on this motherboard could be in the next Mac Pro. If it is, when the next ones come out, I'll sell mine and get one.

Umbongo

Feb 10, 2008, 12:08 PM

lol, if a variation on this motherboard could be in the next Mac Pro. If it is, when the next ones come out, I'll sell mine and get one.

Unlikely. I can't imagine that their is any real money to be made for Apple from it.

diamond.g

Feb 10, 2008, 12:18 PM

Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420.1 (KHTML, like Gecko) Version/3.0 Mobile/4A93 Safari/419.3)

lol, if a variation on this motherboard could be in the next Mac Pro. If it is, when the next ones come out, I'll sell mine and get one.

Unlikely. I can't imagine that their is any real money to be made for Apple from it.

Plus I would think OS X needs to support at least Crossfire first.

Brianna

Feb 10, 2008, 03:58 PM

Unlikely. I can't imagine that their is any real money to be made for Apple from it.

That depends on how much they make on graphics cards, but I wasn't pointing to Apple making money from it as the reason. It's common for for Apple to use the best intel motherboard and XEON processors available in the Mac Pro. And there is the fact that they have never been able to support SLI until now. If it's a question of people using it, there are plenty of threads concerning Apple and SLI at Apples own forums along with every other forum on the internet. And I don't see how it could be a drawback for those who wouldn't want to use it because if you don't want it; just don't buy a second graphics card and you have a standard motherboard.
I think there is a good chance that Apple will have this board in the next Mac Pro. It'll be about a year away before the Mac Pro motherboard is updated if you ask me, but I think there is a good chance that this will be in it. Or at least in the high end version.

TBi

Feb 10, 2008, 06:21 PM

Actually there is a physical limitation. Something about a northbridge needs to be present, and Nvidia SLI MCP's. I've done a little research on this myself. Sorry to burst your bubble. :(

You didn't burst any bubble because you are wrong. SLI doesn't need anything hardware wise on the motherboard (except for dual PCI-E slots which can accommodate graphics cards) to work.

Please prove me wrong :)

diamond.g

Feb 10, 2008, 06:43 PM

You didn't burst any bubble because you are wrong. SLI doesn't need anything hardware wise on the motherboard (except for dual PCI-E slots which can accommodate graphics cards) to work.

Please prove me wrong :)

If you could show me a SLI'ed GF8x rig with hacked drivers I'd be grateful.

TBi

Feb 10, 2008, 07:01 PM

If you could show me a SLI'ed GF8x rig with hacked drivers I'd be grateful.

I can't because i don't have the hacked drivers nor an SLI rig. I also don't really want to look for them or hack the drivers myself.

The limitation is simply driver related, but it needs a lot of work to hack them (or else everyone would have hacked them and they would be readily available).

EDIT: I'm not positive about this, but i read that the nVidia (http://www.xtremesystems.org/forums/showthread.php?t=173467) chip on the skulltrail motherboards simply contains an encrypted "key" which tells the drivers to allow SLI to work. It sounds plausible.

diamond.g

Feb 10, 2008, 07:14 PM

I can't because i don't have the hacked drivers nor an SLI rig. I also don't really want to look for them or hack the drivers myself.

The limitation is simply driver related, but it needs a lot of work to hack them (or else everyone would have hacked them and they would be readily available). 26 Page Thread (http://www.xtremesystems.org/forums/showthread.php?t=106212) talks about using hacked driver to run SLi. From what I have read in it, it doesn't seem like anyone has gotten the GF8 series to work without Nvidia MCP (or SB).

Brianna

Feb 10, 2008, 08:40 PM

diamond.g

Feb 10, 2008, 08:44 PM

No one is saying you couldn't do it with a 7 series card, but from what developers are saying you can not do it now.

Here read up.

http://www.google.com/search?client=safari&rls=en&q=SLI+hack+patch&ie=UTF-8&oe=UTF-8

The 26 page thread that I posted says the GF7 series works great, but they can't get Vista/ XP 64 drivers and they can't get GF8 drivers.

TBi

Feb 11, 2008, 04:45 AM

No one is saying you couldn't do it with a 7 series card, but from what developers are saying you can not do it now.

Here read up.

http://www.google.com/search?client=safari&rls=en&q=SLI+hack+patch&ie=UTF-8&oe=UTF-8

There is still no technical reason for SLI to not actually work. So it's my understanding that nVidia are just doing a better job at locking it down to nVidia only motherboards with more artificial locks built into the drivers.

I've read that they are using a special encrypted key on their nForce chipsets which tell the drivers to allow SLi to work, it's only logical that they've incorporated something similar into the new graphics chipsets to stop something that should work from working.

Just because they haven't done it yet doesn't mean it is impossible, just too hard :)