4 Nvidia 8800 GT

4x8800GT would draw way too much power for the bus. The total draw over the PCI-e express bus must be 300W or less. Each of those cards can draw over 100W. Either some would not power up (probable) or you would damage your logic board (less probable).

 

I would think not. I haven't seen the innards, but I assume there is some sort of proprietary connector somewhere, not to mention the fact that the power plug is centered, whereas 99.9% of the power plugs on retail PSUs are on the right side.

Besides, since NO ONE has the 8800GT in their Mac Pro there is no way anyone can answer your original question.

 

Not even a little bit.

1: SLI is an NVidia only technology.
2: The MP has an Intel chipset.
3: ATI uses a different method called crossfire, and the MP doesn't do that either.

 

Nope, from what I hear, SLI is not supported on a mac.

 

It's 300 watts total for the PCIe bus, so two 8800 GTs should be possible (I want to know, as I want to rock that setup). Guess we'll have to wait until some people get not only their 8800 Mac Pros, but an 8800 upgrade card.

 

Mac's don't have SLI. The only benefit of multiple video cards is to run a ton of monitors.

 

Can I put the 8800 GT on the pci 2.0 slot and an Ati 2600 on one of the other slots for a third monitor?

 

It's possible, but on the previous Mac Pros there were driver problems that resulted in a performance hit when you ran an X1900 and a 7300GT together. I'm not sure if that's been worked out or not.

 

I think folks here on this forum need to read up on the use of XFire and SLi, both from a hardware and software perspective. First, the motherboard in question has to support it. The MP's MoBo doesn't support either.

Game over, right there. The end.

Next, at least with SLi, it's not only a question of operating system drivers, but software/application support as well. In other words, if you want to take advantage of SLi with FC Pro, FC Pro would have to be written for that, specifically.

Not as easy as you might think.

jas

 

Not quite true... PCIE 2.0 allows 150W per lane, previous PCIE 1.0/1.1 allowed 75W per lane. Add in the 6-pin/8-pin PCI-E plugs from a power supply and you'll be able to do cards that draw much more power. For example, the 8800 Ultra draws well over 150W of power (75W from the PCI-E lane, 75 x 2 from 2x6-pin plugs) and yet you can SLI or Tri-SLI them if you want.

As far as there being SLI or CrossFire (ATI's version) on Macs: it won't happen without drivers as they are driver based.

However, SLI is not entirely an Nvidia thing - Workstation motherboards and Skulltrail support SLI on Intel chipsets. CrossFire exists on almost any Intel chipset in the past year or two that has more than one PCI-E x16 lane as well. Without drivers though, having extra video cards only provides extra monitor support (for > 2 monitors).

 

SLI works in Mac Pro, you just need to get the correct drivers. At least, it has been tried in 7xxx series cards. This can be done only when booted up in Windows -- not in OS X.

linky: http://discussions.apple.com/thread.jspa?threadID=612359&tstart=0