ATI 4870 + ATI 3870 in 2008 Mac Pro - my potential solution

[KevinPlusPlus]

I actually got it a few weeks ago and used the driver package from 10.5.6, but wanted to wait to comment until the final drivers were out as part of 10.5.7.

Everything seems to work fine, I haven't had any weird problems that would be indicative of overdraw on the power. The inside of my case is taken up by a lot of video card since the 4870 is huge and the 3870 is huge after the S1 cooler, but once the side is on, who sees that. One potential downside is you are left with only one available 4x PCI Express slot (the very top one). But if you were lucky enough to get a 3870 that isn't a vacuum cleaner then you would still have use of both top slots.

The real test will be to see how things shake out with Snow Leopard and the graphics drivers, if this is really an awesome solution or not...

 

[sparkie7]

ok good to hear its all going okay. I have opened up my Mac Pro and can see everything you describe.

One question is which route/direction have you fed the extension cable from the CD/DVD bay area down towards the video cards?

I tried going out the side towards the removable panel side but can't close the door as the cable gets in the way. The other option I can see is possibly in the far left corner at the back plane where there is a small gap where i could feed the extension cable through. Is this what you did? or did I miss another way?

 

[KevinPlusPlus]

One question is which route/direction have you fed the extension cable from the CD/DVD bay area down towards the video cards?

I tried going out the side towards the removable panel side but can't close the door as the cable gets in the way. The other option I can see is possibly in the far left corner at the back plane where there is a small gap where i could feed the extension cable through. Is this what you did? or did I miss another way?

Yes, the far back is where I did it, with all of the other cables that pass through. I had to loosen the SATA bay 1 SATA connector so that there was enough room to pass the connector through; once the connector is through, there is plenty of room for the cable to rest there with the other bundle of cables that pass through.

Does that make sense?

 

[Spanky Deluxe]

If you want a neater cable solution you could always get some PCIe Y-splitters. I'm using two at the moment so as to power two 4870 cards in my 2006 Mac Pro. Before this I had two 3870 cards, one was a Mac edition and the other a PC (for Windows Crossfire use only). Since I never got round to buying a proper mini-PCie to PCIe cable for the PC card I was powering the 3870 from the Optical bay. Was an absolute pain in the backside to get the wire neatly going through the case but after that it worked just fine for the 9 or so months I had it in there.

 

[KevinPlusPlus]

If you want a neater cable solution you could always get some PCIe Y-splitters. I'm using two at the moment so as to power two 4870 cards in my 2006 Mac Pro. Before this I had two 3870 cards, one was a Mac edition and the other a PC (for Windows Crossfire use only). Since I never got round to buying a proper mini-PCie to PCIe cable for the PC card I was powering the 3870 from the Optical bay. Was an absolute pain in the backside to get the wire neatly going through the case but after that it worked just fine for the 9 or so months I had it in there.

I addressed earlier why I didn't want to split the PCI Express power cables. I know it works for some, but it did not seem like a safe solution to me.

I didn't have much difficulty routing the cable, the only wrinkle I ran into was getting the connector through behind the first drive bay, and that was solved by loosening the SATA connector as I described in my previous post.

There's really no visible mess and it looks all normal Mac Pro awesome.

 

[sparkie7]

I didn't have much difficulty routing the cable, the only wrinkle I ran into was getting the connector through behind the first drive bay, and that was solved by loosening the SATA connector as I described in my previous post.

Did you loosen the HD Bay 1 SATA connector by unscrewing the two screws (phillips) on either of it? I had a closer look again and it looks like you can possibly feed the extension cable to the far left corner and down a gap, albeit its maybe longer by 2-3 inches that way then straighter down from the Bay 1 SATA connector.

Also reading your earlier posts, have you got TWO optical drives in both bays? I only have the standard single optical CD/DVD drive as shipped with my MP 2008. Hence that's why there's a free power connector hanging off the first optical drive (for the 2nd drive). But assuming you have 2 optical drives already in your machine, did you have to get an extra 4-pin molex splitter in order to be able to feed the 3rd PCI Express cable?

Finally have you had any problems/issues with your mini displayport to DVI adapter? Any flicker issues? I assume you have smaller than 30" displays (otherwise you would have got the dual link version)

Thanks again

 

[sparkie7]

If you want a neater cable solution you could always get some PCIe Y-splitters. I'm using two at the moment so as to power two 4870 cards in my 2006 Mac Pro. Before this I had two 3870 cards, one was a Mac edition and the other a PC (for Windows Crossfire use only). Since I never got round to buying a proper mini-PCie to PCIe cable for the PC card I was powering the 3870 from the Optical bay. Was an absolute pain in the backside to get the wire neatly going through the case but after that it worked just fine for the 9 or so months I had it in there.

So you are running two 4870's off the two PCI power connectors on the motherboard? ... thats doubling up the power draw from the two connectors, i wonder if thats too much load if you have the cards cranked up

 

[KevinPlusPlus]

Did you loosen the HD Bay 1 SATA connector by unscrewing the two screws (phillips) on either of it? I had a closer look again and it looks like you can possibly feed the extension cable to the far left corner and down a gap, albeit its maybe longer by 2-3 inches that way then straighter down from the Bay 1 SATA connector.

Yes, I believe that's it. Right on the connector itself were two screws, one on each side. I did not actually take out the screws (I was afraid getting them back in might be difficult) - it only took a few turns to be able to pull the connector forward enough to slide the connector through behind it. And I seem to recall that I could not fashion a way through without doing this, but maybe I missed something.

Also reading your earlier posts, have you got TWO optical drives in both bays? I only have the standard single optical CD/DVD drive as shipped with my MP 2008. Hence that's why there's a free power connector hanging off the first optical drive (for the 2nd drive). But assuming you have 2 optical drives already in your machine, did you have to get an extra 4-pin molex splitter in order to be able to feed the 3rd PCI Express cable?

That is correct, I have the dual optical. I had to use a molex splitter to create the connector for the molex to PCI Express power to plug in. But, since my optical bays are usually idle and drawing no power, I don't think that this is much of a problem. I explained all of my wattage math somewhere earlier. The only way that I could ever conceive of a problem with this split would be if I were to be burning DVDs in both drives at the same time while maxing out 3D, which is highly unlikely, especially maxing out 3D on the secondary card.

Finally have you had any problems/issues with your mini displayport to DVI adapter? Any flicker issues? I assume you have smaller than 30" displays (otherwise you would have got the dual link version)

Nope, haven't had any issues with it. And your assumption is correct - all monitors are 24" or less and work on a single link.

You're welcome, glad to help! I wish I had taken pictures, but it's a pain for me to unhook everything and pull it out, but next time I do, I should snap some and post them just for everyone's reference who may be curious.

If there's anything else you want to know, just ask! Be glad to help if I can.

 

[sparkie7]

Excellent thanks for the clarification

Have you got two displays hooked to your 4870? or just one. Wouldn't that halve its power. Or is it a better idea to only have one display connected to the 4870 for max processing power and have your other two displays connected to the 3870 for secondary work and palettes.

Unless the 4780 can handle two 30" displays without any ill effects to its performance. Anyone know

 

[sparkie7]

Update

I went into the city and went to several computer stores. None had 6 pin PCI-e extension cables. Or longer versions of the 4 pin molex to 6 pin PCI-e cable (like supplied with the 3870).

So I found a store which had a 12 inch 4 pin Molex Y splitter power cable. Bought it and connected it to the spare molex connector hanging off my 1st optical bay drive. Then attached the 3870 supplied molex to 6 pin PCI-e cable to it. I routed it in the far corner and avoided having to play around with the screws on the SATA1 HD bay.

It took a bit of fiddling and flicking with a spare chopstick in the kitchen to reach to the rear of the machine and grab it and pulled it through. A little bit of a tight fit getting the wide'ish molex connector through the gap. But once through the cable Just reaches the 2nd slot where I have the 3870 connected. I think it also helped that I had a (thin) SSD drive in the 1st HD bay so the cable doesnt have to go round a thicker normal 3.5" drive.

Booted up and all seems fine

So I have the 2 motherboard mini-PCI-e power connectors freed up waiting for the 4870 to be plugged in

 

[KevinPlusPlus]

I don't know about the power consumption of one vs. two monitors. I've actually had mine hooked up with 2 to the 3870 and 2 to the 4870 at one time or another, and both configurations worked fine. As for two 30" displays - its in the specs for both cards to run 30" displays so I don't see any reason you couldn't run 4 30" displays if you wanted to.

I ordered the PCI Express power extension from newegg and I'm not surprised it was hard to find in a store. Your longer splitter sounds like it did the trick, though, I just used a 4" splitter I already had. I should have mentioned too that I took out the fan assembly in the front to route the cables, maybe that went without saying but just to be explicit in case anyone else wants to try it, that sure makes it easier.

Congrats on the mod and I'm glad that my information was helpful!

 

[sparkie7]

I don't know about the power consumption of one vs. two monitors.

sorry for the confusion but i meant the graphics card processing power (not the electrical power draw) if 2 displays were connected as opposed to just one. And whether its processing "through put" would be halved or affected by having dual displays on just one card. I would have thought so as the 512MB would be split

I should have mentioned too that I took out the fan assembly in the front to route the cables, maybe that went without saying but just to be explicit in case anyone else wants to try it, that sure makes it easier.

Congrats on the mod and I'm glad that my information was helpful!

Heck I did all my modding without removing the fan. Thats why I needed the aid of a chop-stick LOL. Got the end result I wanted regardless

Thanks for all your help Now just got to pick up the 4870 from the Apple store tomorrow and the MDP DL adapter. Fingers crossed I won't have any flicker/display issues

 

[KevinPlusPlus]

sorry for the confusion but i meant the graphics card processing power (not the electrical power draw) if 2 displays were connected as opposed to just one. And whether its processing "through put" would be halved or affected by having dual displays on just one card. I would have thought so as the 512MB would be split

Hmm, yeah. I think it's not so much the number of monitors but the total number of pixels. So, you could probably run 2 17" monitors or one 24" monitor and have the same throughput, for example... I didn't run the math but I think you get the idea.

 

[sparkie7]

Hmm, yeah. I think it's not so much the number of monitors but the total number of pixels. So, you could probably run 2 17" monitors or one 24" monitor and have the same throughput, for example... I didn't run the math but I think you get the idea.

yeeaah I kinda see to a point, put its also dependant on files and complexity of graphics. you could have two 24" displays each on separate cards, but one display could be rendering 3D and it would put the load way on that card.

since you have a 3870 and 4870 like I have, what displays have you got plugged into which card?

also have you done OpenGL tests? be interesting to see your scores

 

[KevinPlusPlus]

yeeaah I kinda see to a point, put its also dependant on files and complexity of graphics. you could have two 24" displays each on separate cards, but one display could be rendering 3D and it would put the load way on that card.

since you have a 3870 and 4870 like I have, what displays have you got plugged into which card?

also have you done OpenGL tests? be interesting to see your scores

I've changed how I have them, but currently I have a 22" hooked up to the 4870 and a 24" and 20" hooked up to the 3870. I have a mini Dispayport to Dislayport cable on order so that I can move the 24" on to the 4870. (It's the only monitor I have with Dispayport.) While the DP-DVI adapter works, I was doing some troubleshooting (unrelated to the adapter) and just ended up with them plugged in the way they are and am too lazy to change it back.

I haven't really done any benchmarks, but individually they would benchmark the same as standalone cards in other Macs.

The one everyday thing that I notice a lot of difference on vs having the dual 2600's is that spaces, expose and video scaling are much smoother.

 

[sparkie7]

I have just plugged in the both 30" ACDs into the 4870. One straight to DVI, and the other via the MDP DL adapter. So far no noticed any flicker but its very early days.

I did an Open GL test using OpenGL Extensions Viewer on each card(XBench and Geekbench are useless for graphics benches)

Results are:

3870 is on average 270% more powerful than the 2600XT

and the 4870 is on average 32% more powerful than the 3870. a bit disappointing

 

[KevinPlusPlus]

I think that where these more powerful cards will really shine is with Snow Leopard, but we'll just have to wait and see.

 

[sparkie7]

lets hope so

 

[ryanschmidt]

I know this is a pretty old thread but I am having the same issue. I was wondering if there is now a new method of doing this... I thought for sure I saw a cable for sale that would do this without needing extenders, etc.

I have 4 displays. When I plug in the 4th it doesn't work. Reason being: not enough power. I get the error when I boot into OS X about the card not having enough power. It powers 1 display just fine, but can't handle 2.

Any help is welcome. Thanks!

 

[MacVidCards]

I know this is a pretty old thread but I am having the same issue. I was wondering if there is now a new method of doing this... I thought for sure I saw a cable for sale that would do this without needing extenders, etc.

I have 4 displays. When I plug in the 4th it doesn't work. Reason being: not enough power. I get the error when I boot into OS X about the card not having enough power. It powers 1 display just fine, but can't handle 2.

Any help is welcome. Thanks!

Are you certain you don't just have one of the 4870s that is single display without a "helper" kext?

You should probably mentin exactly which cards you have.

Many of the newer 4870 and 4890 cards have the "power not plugged in" message even wen they are properly plugged in. You could have these cards wired directly to a Nuclear Reactor and this message would still appear.

 

[ryanschmidt]

I have 4 displays, a 3870 and a 4870 just like the original poster

 

[MacVidCards]

I have 4 displays, a 3870 and a 4870 just like the original poster

The Apple 4870 or a flashed one?

If flashed, which one?

 

[ryanschmidt]

The Apple 4870 or a flashed one?

If flashed, which one?

Both cards are Mac compatible by default. Not flashed

 

[MacVidCards]

Both cards are Mac compatible by default. Not flashed

Sounds like you didn't run 2nd cable to 4870?

If so, it is running in 2D "limp home" mode.

 

[ryanschmidt]

Sounds like you didn't run 2nd cable to 4870?

If so, it is running in 2D "limp home" mode.

I really wish it was that simple. THe 4870 power cords are both connected. The power issue is with the 3870. I believe the 3870 requires another power cord but the motherboard doesn't have enough.