What went wrong? Ranting!
Since we seemed to be having trouble with Quad SLI (two GeForce 7950GX2 cards) working we grabbed a pair of 7950GX2 stock clocked Leadtek cards locally. Since these were card only (no package) and we did only have them for a few hours, we didn't get any further than having a look at performance when compared to our overclocked XXX XFX graphics card sample.
The main problem we had is the drivers had "QUAD SLI" ticked which made us think we were good to go. We then turned on the load balancing graph which shows you how much load is being put on the card (or core) and at the moment because its only halves the screen, which is the same as when you're running two regular cards in SLI, we aren't entirely sure. If we didn't have a logo saying "QUAD SLI" in the top left corner we might not have been so concerned about the results we were getting. This was about 200 - 300 marks extra in 3DMark when running at 2560 x 1600 and we think with our AMD Athlon FX-60 this is NOT a CPU limitation, as you will be able to see the performance of the overclocked XFX card and the stock Leadtek card, in just a few pages.
Now while we didn't get a chance to have a look at the Leadtek boxes, the company we got them from assured us that "QUAD SLI" was printed on the front of the box. XFX doesn't have Quad SLI on their retail box.
So, while we could have knocked over most the testing in two long days, we spent five long days trying to get Quad SLI working all because nVidia didn't feel like marking their drivers better. There where a few things that led us to believe that Quad SLI wasn't working by the fifth day. The most obvious was the fact that the performance difference was nothing and the other thing that stood out was the fact that the card in the slot furthest away from the CPU didn't seem to generate as much heat. The other problem is the nVidia drivers don't give us a read out for four GPUs under the temperature monitoring area.
The worst thing about it all, we really do feel for a lot of people, because not everyone reads reviews. So what happens when you walk into your local computer store and go say, "I want the best VGA setup" - that computer store bases their judgment off price tag says to the uneducated consumer, "Oh this is what you want, the 7950GX2 which enables Quad SLI." The end-user takes his advice and purchases it, goes home sets it up and think it's kicking butt. The problem is the buyer doesn't know that two cards are just sitting in their slots generating extra heat, placing more strain on the power supply and increasing his electricity bill.
With that rant out the way, the good news is that it looks like Quad SLI is going to be seen soon as nVidia improve their driver support. With this said though, it looks like this was heard from one website that another website mentioned etc etc and may be nothing more then a game of Chinese whispers. We have our fingers crossed it isn't but if the GX2 results we saw from our Gigabyte 7900GX2 review are anything to go by, at the moment, the only real game to see performance increases is F.E.A.R. While we are on the subject of F.E.A.R. we did see a performance increase in our testing today, like many other websites. When we saw we say a performance increase of 200 - 300 marks in the 3DMark series, we're talking a few % but when moving to F.E.A.R. we saw increases of 20%. This makes the whole situation even worse to decipher though - is Quad SLI working but it is not yet optimized properly? The drivers say Quad SLI, the load balancing say Quad SLI and the F.E.A.R. results say the next set of cards are doing something.
Maybe Quad SLI does work and it's no good or maybe there really is just an issue that a new revision driver will fix with optimization - we think the latter. There is no doubt we will know in the next few weeks but we wish we knew now to provide you with an accurate conclusion about the GeForce 7950GX2.
Upon conclusion of this little rant, we can say that there must be some form of Quad SLI doing something for F.E.A.R. to see a performance increase of roughly 20%. The biggest impact that Quad SLI has given us is a lot less sleep over the past week. Something we don't want our readers to experience.
With that out the way, let's move onto the XFX 7950GX2 in more detail before we have a look at the results.