Integration and SLI
We bring up integration again because using a 7950 GX2 is not the same as using another single-GPU, single-board graphics product, because of its physicals and SLI, and its compatibility isn't universal.We tried the reference board on Intel's D955XBK with no boot, and the ASUS A8R32-MVP (Radeon Xpress 3200 Crossfire) with installation success but death upon init of Direct3D. Doh, since both boards are on the supported list and we tested with the BIOS revisions NVIDIA say should work.
Everything with an nForce chipset that we tried took it just fine, though, including ASUS M2N32-SLI (nForce5 590 SLI), ASUS A8N32-SLI (nForce4 SLI x16) and DFI LanPartyUT nF4 SLI-D (nForce4 SLI).
And since it's SLI, when it does work you get the same restrictions for display output. Both DVI outputs can't be active while it's in multi-GPU mode, meaning a tedious (and not always successful without a full reboot) settings change for dual-head users like me and many of you. When you game with two heads on a regular single GPU graphics board, the 2nd head stays on. The new NVIDIA control panel shows you the toggle.
SLI game profiles and IQ
If you're going to run it on a board that supports it, and the display configuration issue doesn't phase you, you've then got to consider the eternal barrier to any multi-GPU configuration on the PC, SLI or otherwise: game compatibility.You see Crossfire and SLI don't work out of the box for all games titles, despite what you might be told. SLI requires driver support at the minimum, and application support on top of that in the best case, to make sure things works smoothly. And while NVIDIA's display driver lets you setup new profiles for games it doesn't know about, testing the variety of SLI rendering modes, you're not guaranteed any level of success.
Use a GX2 and you face the same issues as a 'normal' SLI user. The driver is helpful in that respect, but some games titles simply don't work, rendering (ho ho) half your GX2 redundant. It's a well understood situation for all current SLI users and hopefully those considering it, and the reality is that it might not be any problem whatsoever, if the games you play have and will continue to have good support.
Definitely worth pointing out, since the title of "fastest single graphics card ever", will realistically only apply in supported situations, should the on-paper promise translate.
Again, since it's SLI, you get access to SLI antialiasing modes, where the two GPUs combine to increase AA quality for the approximate performance you'd get from a single GPU at its lesser equivalent mode. Think 8x SLI AA performing at the level of single GPU 4x AA. But remember the way the hardware goes about the business of multisampling means that the IQ from 8x say, isn't what you'd get from a multisample mode with a true EER (edge equivalent resolution, a measure of sub-pixel coverage) of 8x8, where each sub-sample occupies its own discrete planar space in the pixel.
And as mentioned on a previous page, the heat produced is fearsome, requiring use of a well ventilated chassis moreso than any single graphics card we've yet tested. Which makes us wonder about factory overclocked versions and what they'll make the user deal with, bringing us on nicely to one such example.
