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Ozy

macrumors regular
Original poster
Aug 8, 2006
139
4
Goodyear, AZ
On my 2008 MacPro, I have two 8800GT's working fine in all regards to normal Desktop Usage. But in World of Warcraft, when I move the WoW window onto either screen on card 2, the frame rate drops to less than 10fps. If I move it back to either screen on card one, its fast again. This may be a localized issue with WoW.

Thanks
 
Are you sure that there is enough power to run two 8800GTs?

Apple doesn't let you configure one that way... I honestly don't know the answer to this. There are ONLY two reasons:

1) The machine can't handle it for WHATEVER reason.

2) The supply of 8800GTs was so low to begin with they didn't want to keep people waiting.

Have you tried any other games that do windowed mode? Civ IV, etc?
 
Hey! Someone else who wants two 8800 GT! So you have one monitor plugged into each, eh? How well do they run? What about Windows? Sorry for not knowing anything about your problem... POST PICS! :D

There is no Expansion Slot Utility on the 2008 Mac Pro; they're hardwired as is.

Yes, there's enough "power" for two. There was just a low supply. And yes, try another game and see what happens.
 
Are you sure that there is enough power to run two 8800GTs?

Apple doesn't let you configure one that way... I honestly don't know the answer to this. There are ONLY two reasons:

1) The machine can't handle it for WHATEVER reason.

2) The supply of 8800GTs was so low to begin with they didn't want to keep people waiting.

Have you tried any other games that do windowed mode? Civ IV, etc?

Yes, the macpro does have sufficient power. The dev notes say this about the power limits on the mac pro:

From: http://developer.apple.com/document...ation.html#//apple_ref/doc/uid/TP40003937-SW6
Each PCI Express slot provides 3.3 V and 12 V power rails. On the 3.3 V rail, each slot may use a maximum of 10 W. On the 12 V rail, each slot may use a maximum of 65 W (not including auxiliary power), subject to the total wattage rules listed below.

When populating the four PCI Express slots, you need to conform to the following total wattage rules:

Slots one and two (not including aux power), max slot power per slot: 75 W
Slots three and four (not including aux power), max slot power per slot: 40 W
All four slots (not including aux power), max total power: 200 W
Max aux power per connector: 75 W
Max aux power for both connectors: 150 W
Max total PCI Express power (slot power and aux connector power): 300 W

That 75W per slot for slots one and two are WITHOUT using the aux power connector. The 8800GT consumes 110W per card max and when you subtract the 75W the aux power provides to the 8800GT, that means the card only pulls 35W from the PCIe slot. Plus these numbers are at full GPU load, which rarely happens if ever for both cards at once. Using hardware monitor, it reports that GPU1 on my primary screen is at 50% usage, while GPU2 is only at 3%.

http://developer.apple.com/document...tion.html#//apple_ref/doc/uid/TP40003994-SW17

This means that TWO 8800GT's fall well under the defined maximum for the MacPro 2008 model.
 
Hey! Someone else who wants two 8800 GT! So you have one monitor plugged into each, eh? How well do they run? What about Windows? Sorry for not knowing anything about your problem... POST PICS! :D

There is no Expansion Slot Utility on the 2008 Mac Pro; they're hardwired as is.

Yes, there's enough "power" for two. There was just a low supply. And yes, try another game and see what happens.

I have 4 LCD monitors. A 24" on port 1 of each card and a 20" on port 2 of each card. I don't run bootcamp on my macpro so i can't answer that question for you. WoW is the only game I play on this machine.

I mount them with a custom Ergotron mount I ordered directly from them.

0Y5W1407.jpg
 
why would u need two 8800? except for more than 2 monitors?

does 2 of those improve graphics performance? i thought there's no SLI setup on the mac?
 
I have 4 LCD monitors. A 24" on port 1 of each card and a 20" on port 2 of each card. I don't run bootcamp on my macpro so i can't answer that question for you. WoW is the only game I play on this machine.

I mount them with a custom Ergotron mount I ordered directly from them.

That setup is insane! I'm jealous ;)
 
On my 2008 MacPro, I have two 8800GT's working fine in all regards to normal Desktop Usage. But in World of Warcraft, when I move the WoW window onto either screen on card 2, the frame rate drops to less than 10fps. If I move it back to either screen on card one, its fast again. This may be a localized issue with WoW.

Thanks

How the hell you get 2 when I'm still waiting for my first!! :eek:
 
why would u need two 8800? except for more than 2 monitors?

does 2 of those improve graphics performance? i thought there's no SLI setup on the mac?

Thats exactly why I have two, because I have 4 screens. On my old macpro, i mixed ATI + NV. This caused many issues with various applications. Aperture, iMovie, and others behaved improperly. I did not want to deal with a mix of Kext's like before and just bought two of the same. That way OS X uses the same driver for both. There is no SLI, and i'm not interested in SLI.

I got my second 8800GT before i got my macpro. I ordered it as soon as it was on the store site.
 
I have 4 LCD monitors. A 24" on port 1 of each card and a 20" on port 2 of each card. I don't run bootcamp on my macpro so i can't answer that question for you. WoW is the only game I play on this machine.

I mount them with a custom Ergotron mount I ordered directly from them.

0Y5W1407.jpg

Nice desk, I built mine from Ikea for $80!!

2323108754_0d6bbf737c_b.jpg
This is right side of the room!!

2323108760_2414b5eaaa_b.jpg
left side of the room! hehe I can tell that you are a instrumental phile and I'm an visual/audio phile!! :D

2323108780_8ff281b366_b.jpg
hehe front view!!:):apple:

2323108770_6219507cdd_b.jpg
Good ol Theatre chair that I found brand new from compusa's close out for $239.99!!

I'm actually thinking about adding a 2nd monitor to my mac pro setup, you guys think a dell would be fine... I was thinking about getting another 23" ACD but might be a lil over kill. Anyone try out the dell 2408??
 
that's a very nice setup you got there!

Yes, it's beautiful. If envy was my bag, I'd be envious... but I meant pictures of the inside and both 8800 GT in all their glory! Where do they plug in, and how many places are there to plug in cards?

I'm curious to know whether or not I'd be able to have two powered cards and still be able to have a PCIe USB/FireWire card that needs a 4-pin molex in another slot.
 
On my 2008 MacPro, I have two 8800GT's working fine in all regards to normal Desktop Usage. But in World of Warcraft, when I move the WoW window onto either screen on card 2, the frame rate drops to less than 10fps. If I move it back to either screen on card one, its fast again. This may be a localized issue with WoW.

Thanks

Have you ran the expansion slot utility to see what speed the second slot you have the other card plugged into is running at? My guess is it's at 1x or 4x.
 
Have you ran the expansion slot utility to see what speed the second slot you have the other card plugged into is running at? My guess is it's at 1x or 4x.

You can't do that in the 2008 model, and slots 1 and 2 are 16x hardwire slots. System profiler reports both cards at 16x lanes.
 
Keep in mind that you're asking to program to switch graphics cards while it's running. That's an unusual request, and Blizzard probably hasn't tested it.
 
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