SLI works

Who's whining? Current cards notwithstanding, once the AMD/ATI deal is finalized I predict a falloff in Mac support from this company. If I'm wrong, I'll buy you a lobster dinner 🙂

CW2k, do the cards work in SLI mode (in Windows) without an SLI bridge flex cable? Or would I actually get a better framerate with one? (someone pointed toward http://www.amdzone.com/modules.php?op=modload&name=Sections&file=index&req=print page&artid=168 which says a cable would boost SLI performance, but it's a year old).

It's not a problem with the physical connection as they are both PCIe. It has to be an issue with the rom but that seems really strange that it would be totally incompatible.

More research nneded on this...

-gl

Im wondering if anybody did benchmarks with ATI X1900
on WinXP ... Would be very interesting to compare
results.

Actually I did:
3DMark Score 6089 3DMarks
SM 2.0 Score 2132 Marks
SM 3.0 Score 2369 Marks
CPU Score 4570 Marks

Graphics Tests
1 - Return to Proxycon 16.369 FPS
2 - Firefly Forest 19.16 FPS

CPU Tests
CPU1 - Red Valley 1.529 FPS
CPU2 - Red Valley 2.185 FPS

HDR Tests
1 - Canyon Flight (SM 3.0) 23.123 FPS
2 - Deep Freeze (SM 3.0) 24.254 FPS

By comparing these results against several pc systems with 1 dual core 4Ghz cpu (not xeon) equipped with ATI X1900
I have sadly to report that mac pro scores less than half the graphics performances of those systems (we're around 40%). The Cpu as you expect scores very well (higher than those systems even if Xeon is not relly geared toward games). I have tried to install the new Catalyst 6.8 drivers from ati: they works well, but are slightly less performant than the apple drivers (score 6075). On my opinion this seems to be a pci express bus issue. It is like the bus is working at 8x instead 16x. Also in Photoshop under XP if you draw a line even on a small image you register some lag between the mouse pointer and the line itself. Anyone reporting the same problems?
Also I have to report that windows xp sees my dvi ports switched (1 becomes 2 and vice versa). Very annoing.
Again this problem doesn't seems to be related to apple drivers since it is there even with catalyst 6.8.

Question: Do you think cross fire is going to work too as it seems to be for SLI?
Take care.

Hey SJS
give a shot to run 3dmark 2006. You can compare then your results on www.futuremark.com.
On my mac pro I get this:

3DMark Score 6089 3DMarks
SM 2.0 Score 2132 Marks
SM 3.0 Score 2369 Marks
CPU Score 4570 Marks

It would be interesting to know your outcomes since I have compared against pc systems and we get less than half framerate (around 40%). Sob.

The critical question: how did you get Bootcamp to see the second graphics card you used for SLI? Out of my two 7300s, Windows device manager will only detect one or the other, but not both at once. Was it the special hacked driver you used? And if so, could you point me towards it?

Did you make the changes to the PCIe bus to allocate the lanes?

-gl

No, though that was intentional. At this point I just want WinXP to SEE my second card. The weird thing is, when XP boots it does the title screen on my secondard monitor connected to the GF7300 in slot #4, but upon initialization the desktop comes up on my primary monitor connected to the GF7300 in slot #1. Even weirder is that XP boots with my GF7300 in slot #4 just fine if I unplug my primary display.

So obviously Windows has some measure of detection for each card. But once I'm actually in the OS, it thinks I only have the one primary monitor connected (there's no second monitor listed in Display Settings) and Device Manager only reports one GF7300.

Does anyone else have success in just getting XP to recognize that there's a second card? Would messing with the configuration help?

Monday morning bump.

Is bootcamp just not capable of two grapics cards at once? This SLI thread implies bootcamp can at least SEE the second card...

Works!

I used the Apple utility to adjust the SLI to 4x 4x 8x 8x, put a GF7300 GT in each 8x slot, connected the SLI bridge, and booted into XP in bootcamp. XP immediately freaked out and did the ugly-*** 8-bit color mode while it informed me I had new hardware and drivers to install. I declined to search for new drivers or even to install the drivers Apple provided. Instead, I installed the hacked SLI Forceware drivers. Bingo! Two "this driver is unsigned" and "continue anyway" messages later, I restarted with full use of both graphics cards, all three monitors, and the option to turn on SLI!

The Flight Simulator X demo worked great, both in SLI on one screen, and in triple monitor mode (though with a little graphical corruption, but who's counting?)!

Correction: when I said, "I used the Apple utility to adjust the SLI to 4x 4x 8x 8x" I meant to say I used the Apple utility to adjust the PCI-slots. OSX doesn't see the SLI so far as I can tell.

Expansion Slot Utility.app

I copied it out of System/Library/CoreServices.

So SLi does really works and how is it.

It's... fine. Not like you'll get a huge performance boost out of two 7300s, but it works, with slight but noticable performance increase. For my purposes, though (Flight Simulator) I'd actually rather run in triple monitor mode though than run my cards in SLI which is only on one monitor by definition.