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skiffx

macrumors 6502a
Original poster
Feb 5, 2008
681
10
I have a dilemma, whether to get a more powerful 5870, and then run my 4th monitor via a usb videocard (already have one) as well as sacrifice not plugging in my tv to stream movies (will need to disconnect one of the monitors) or get 2x5770s which will enable me to drive 4 monitors plus my tv and run them in crossfire for gaming in windows (if possible)? I would rather get the 5770s if somebody can confirm that it is possible to crossfire them somehow.
 
I have a dilemma, whether to get a more powerful 5870, and then run my 4th monitor via a usb videocard (already have one) as well as sacrifice not plugging in my tv to stream movies (will need to disconnect one of the monitors) or get 2x5770s which will enable me to drive 4 monitors plus my tv and run them in crossfire for gaming in windows (if possible)?

I doubt it.
1. The motherboard has to be certified to use crossifre/sli
2. The 5770 needs a crossfire finger( which i doubt it has)
3. You need a crossfire bridge as it will not work over the pci bus.
 
The PC Cards work.... I've done it in both my MPs...

Works perfectly in an Original (1,1) and a 2008 (3,1) MP!

Don't know about apple's cards, but I would imagine they work too...
 
I doubt it.
1. The motherboard has to be certified to use crossifre/sli
2. The 5770 needs a crossfire finger( which i doubt it has)
3. You need a crossfire bridge as it will not work over the pci bus.

And you are wrong... crossfire/sli is more of a software implementation on top of the logic board. Do a little search and you will find that member of this same forum have been able to sli two gtx 285's on a nehalem mac pro.
 
So I guess I can get the 2 5770s for now and see if they work, even if not, single 5770 still should have adequate performance in games for the next year or so ... after which I can sell them both and replace them with something more powerful in crossfire ?

Of course would be cool to see if it would be possible to CF the stock ones.
 
The PC Cards work.... I've done it in both my MPs...

Works perfectly in an Original (1,1) and a 2008 (3,1) MP!

Don't know about apple's cards, but I would imagine they work too...

Was it difficult to do or... ? Care to elaborate what was necessary to accomplish it?
 
Was it difficult to do or... ? Care to elaborate what was necessary to accomplish it?

Couldn't be easier!

Just install one of the ATI cards, fire up Windows, install the ATI catalyst software, shut down, install both cards, link them with the crossfire bridge, start the mac up again - you are in crossfire mode!

If you want to see what's happening during boot, you can even leave your 8800GT or 7300 installed at all times (Other cards will probably work too, but those are the stock ones I have)...
 
Couldn't be easier!

Just install one of the ATI cards, fire up Windows, install the ATI catalyst software, shut down, install both cards, link them with the crossfire bridge, start the mac up again - you are in crossfire mode!

If you want to see what's happening during boot, you can even leave your 8800GT or 7300 installed at all times (Other cards will probably work too, but those are the stock ones I have)...

Hmm the apple's 5770 might be somehow handicapped specifically to prevent it, but I guess I can use them both for the next year or so.

Thanks.

Edit: Then sell them and upgrade them if such choice will be a possibility.
 
And you are wrong... crossfire/sli is more of a software implementation on top of the logic board. Do a little search and you will find that member of this same forum have been able to sli two gtx 285's on a nehalem mac pro.

Wow. You are wrong. You do some research. The 285s had a SLI FINGER. No duh it works.....

OP it most likely does not have a crossfire finger, your best bet is to buy two PC 5770s and flash them.. Those will have the finger.
 
Wow. You are wrong. You do some research. The 285s had a SLI FINGER. No duh it works.....

OP it most likely does not have a crossfire finger, your best bet is to buy two PC 5770s and flash them.. Those will have the finger.

Or build a hackintosh already :)
How hard is it to flash the cards?
Thanks for your input.
 
Does the motherboard support crossfire? Yes.

but does the cards?

apples 4870 cards had crossfire connectors on them, but they didnt work in crossfire. So people assumed apple had disabled it.

then 5 months later, a ATI Windows driver update suddenly made crossfire work on the apple cards too.


so, apple's 5000 cards... disabled crossfire? disabled in drivers? or working fine? up for someone to test.
 
I have a dilemma, whether to get a more powerful 5870, and then run my 4th monitor via a usb videocard (already have one) as well as sacrifice not plugging in my tv to stream movies (will need to disconnect one of the monitors) or get 2x5770s which will enable me to drive 4 monitors plus my tv and run them in crossfire for gaming in windows (if possible)? I would rather get the 5770s if somebody can confirm that it is possible to crossfire them somehow.

Just get the 5870.

A 5870 is quite literally twice as fast as a 5770. Cross firing two 5770's will only give you the same performance as the single card, with actually a bit of a performance hit because of the crossfire.

Drive your third and fourth display off a GT 120. Cheaper config, and it will work better. (Or use your USB video card.)
 
Does the motherboard support crossfire? Yes.

but does the cards?

apples 4870 cards had crossfire connectors on them, but they didnt work in crossfire. So people assumed apple had disabled it.

then 5 months later, a ATI Windows driver update suddenly made crossfire work on the apple cards too.


so, apple's 5000 cards... disabled crossfire? disabled in drivers? or working fine? up for someone to test.

Spoke to an apple genius guy today in the store, he basically said the same thing. He said that apple is going to handicapped purposefully any cards, but its up to ATI drivers...
 
Just get the 5870.

A 5870 is quite literally twice as fast as a 5770. Cross firing two 5770's will only give you the same performance as the single card, with actually a bit of a performance hit because of the crossfire.

Drive your third and fourth display off a GT 120. Cheaper config, and it will work better. (Or use your USB video card.)

I wasnt aware that you can stick another card with 5870 in there? Since it will be my first MacPro I was under assumption that the reason why they offer single 5870 is because it takes 2 power connectors that otherwise power 2 individual cards? If thats not the case, Ill gladly opt out for 5870 and some old, silent card to simply drive monitors, and use only 5870 in windows for games. (I also have a usb card, but performance is laggy even when you drag windows across, and I dont want to experience that in a 4K machine.)
 
I wasnt aware that you can stick another card with 5870 in there? Since it will be my first MacPro I was under assumption that the reason why they offer single 5870 is because it takes 2 power connectors that otherwise power 2 individual cards? If thats not the case, Ill gladly opt out for 5870 and some old, silent card to simply drive monitors, and use only 5870 in windows for games. (I also have a usb card, but performance is laggy even when you drag windows across, and I dont want to experience that in a 4K machine.)

The GT 120 doesn't require any power connectors. Great lil card to drive a second display, almost as powerful as an 8800... You should be able to support at least one, maybe two, with the 5870.
 
The GT 120 doesn't require any power connectors. Great lil card to drive a second display, almost as powerful as an 8800... You should be able to support at least one, maybe two, with the 5870.

Thats awesome, how are they (GT120s) with noise? Overall thank you, that's a very possible solution to my problem.

Edit: Also one can be picked up on ebay for around 50-75$ which is approximately the difference between getting 5870 or 2x5770s
 
I doubt it.
1. The motherboard has to be certified to use crossifre/sli
2. The 5770 needs a crossfire finger( which i doubt it has)
3. You need a crossfire bridge as it will not work over the pci bus.

1. No, Crossfire doesn't need certification unlike SLI which requires nVidia approval.
2. Crossfire Bridge, and in any case, you can buy one on eBay. ;)
3. See above.
 
Thats awesome, how are they (GT120s) with noise? Overall thank you, that's a very possible solution to my problem.

Edit: Also one can be picked up on ebay for around 50-75$ which is approximately the difference between getting 5870 or 2x5770s

They have a fan, but very quiet. I run one with at home with an 8800 and the 8800 is definitely louder. My work Mac Pro shipped with a single GT 120 and I never hear it, although the office isn't entirely quiet. But even when I'm the only one there I never hear it.
 
Or build a hackintosh already :)
How hard is it to flash the cards?
Thanks for your input.

No its not hard, but you will need access to a windows 32bit version machine.. 64bit is a no go and you will screw the cards up. Also, one thing to note is efi is generally 128kb in size and Pcs bios range from 64kb to 128kb.. make sure you get a 128kb card other wise during the flashing process it will not finish writing the new efi to the cards rom rendering the card useless
 
Well problem is I dont want to risk ordering machine with dual 5770 only to find out that it might not work. I think 5870 plus a gt120 from ebay is a safer route (as long as gt120 is quiet) since 5870 will do all the graphic intensive stuff like gaming, and the gt120 will drive secondary monitors.

What do you guys think?

P.S. Yes once people start receiving them we'll find out if its possible for CF the 5770s in Windows, however, who can wait that long ?! :D
 
Just get the 5870.

A 5870 is quite literally twice as fast as a 5770. Cross firing two 5770's will only give you the same performance as the single card, with actually a bit of a performance hit because of the crossfire.

Drive your third and fourth display off a GT 120. Cheaper config, and it will work better. (Or use your USB video card.)

2 5770s cost 300$. 1 5870 costs 400$.. 100$ less for similar performance. Seems like a no brainer to me. Hell if i were OP id crossfire two 5830s,which is same price as the 5870, and use them for Windows while using the gt120 for Osx.
 
2 5770s cost 300$. 1 5870 costs 400$.. 100$ less for similar performance. Seems like a no brainer to me. Hell if i were OP id crossfire two 5830s,which is same price as the 5870, and use them for Windows while using the gt120 for Osx.

you mean if you buy 3rd party and not from apple?
Two ATI Radeon HD 5770 1GB [Add $250.00]
ATI Radeon HD 5870 1GB [Add $200.00}

So if you go via apple, it's 50$ cheaper to get 5870, and use 50$ towards gt120.

Otherwise you can get MP with one 5770. then purchase 2 PC 5770s, flash them and then sell 5770. But tbh that seems like a hassle to somebody who hasnt flashed nor likes dealing with selling on ebay, compared to sticking one gt120.
Although 3rd party 2x5770s will consume less power than 5870 and gt120 and might even produce less noise.
 
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