Previously, when you wanted two 3D cards inside your PC (for the purposes of fast, high-resolution, high-detail gaming), you needed to buy two cards from ATI or Nvidia, plug each card into your PC's power supply, and join them together via either Nvidia's internal SLI connector or ATI's external CrossFire dongle. Through that process, you limit your expansion options--the bulky cards block adjacent slots--and increase the likelihood of requiring a massive power supply. Thanks to its all-in-one dual-3D-chip package, the GeForce 7950 GX2 solves all of those problems. A single GeForce 7950 GX2 still takes up two expansion slots' worth of space, but instead of losing two adjacent slots, now you lose only one. And because it requires but a single connection to your PC's power supply, you don't need the 600-watt, 750-watt, or 1-kilowatt power supplies that have become far too common. Instead, Nvidia recommends only a 400-watt power supply to power a single GeForce 7950 GX2, a marked improvement.
So it's neither the design of the card nor its requirements that hold us back, but rather the 3D chips themselves. The GeForce 7000 series has been a solid performer for Nvidia. It helped usher in the dual-card SLI era, and even though ATI's Radeon X1000's can jump through a few more hoops, I think most gamers would argue that this current generation of 3D chips has served the gaming public well. If that sounds like an epitaph, you're not far off. The problem is Windows Vista, or more specifically, Vista's updated multimedia programming interface, DirectX 10.
DirectX is Microsoft's Rosetta stone for combining hardware and software. As long as software programmers and hardware developers design their products to cue into DirectX, compatibility should be guaranteed. The current version for Windows XP is DirectX 9.0c. Microsoft has stated that Vista will support DirectX 9 software and hardware but that the OS will ship with DirectX 10. The GeForce 7950 GX2 (along with the rest of the GeForce 7000 series), however, is a DirectX 9 part. This means that while it will work with Vista, it won't support the latest and greatest 3D features, so your $600 investment will be out-of-date only six months after you buy it, assuming Microsoft hits its targeted January Vista release date. While Nvidia (or ATI) has yet to announce a DirectX 10 chip, you can bet that such cards will be out or will be very near release by the time Vista launches.
All of which is too bad, because the GeForce 7950 GX2 really is a fast 3D card. Its core specs aren't as fast as Nvidia's single-card flagship, the GeForce 7900 GTX. That card has a 650MHz clock speed for the GPU and 800MHz for the memory, whereas the GeForce 7950 GX2 has a 600MHz GPU clock and only 500MHz for each chip's 512MB of DDR3 RAM. We're not surprised by the clock speed reductions given the heat and power issues inherent to running two fast GPUs in a single-slot package, but we were surprised by the performance results. (Props to Sarju Shah, GameSpot's illustrious associate hardware editor, for sharing his benchmark scores with us).
|1,600x1,200 (max. quality, no AA, no AF)|
On most of the charts, the GeForce 7950 GX2 hangs so close to a pair of GeForce 7900 GTX cards that the performance is basically the same. That's especially impressive given that two 7900 GTX cards will run you about $1,000. ATI's Radeon X1900 XT running in CrossFire mode wins by 500 points or so on 3DMark, but that too is an expensive setup, going for roughly $950. ATI still wins for 3D image quality, since on some games you can turn on more image quality features at the same time. But from a sheer dollars-per-frame-rate point of view, if Nvidia had released the $600 GeForce 7950 GX2 even three months ago, we might have called it the best deal we'd ever seen.
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|High Quality mode, 4X antialiasing, 8X anisotropic filtering|
If you're wondering about whether you can build your own GeForce Quad SLI PC now that the 7950 GX2 seemingly makes it look easy, the answer is not yet. The 7950 GX2 is Quad-capable, but like the first generation GeForce 7900 GX2 boards, Nvidia will keep Quad SLI system-builder only for now. From what we understand, Nvidia is waiting to get the drivers ready and is making sure the retail motherboards are all up to snuff. Along with the press review material, Nvidia sent us a list of motherboards and the BIOS updates we'd need to make for each of them to get Quad SLI to work. We imagine that Nvidia wants to wait for the motherboard compatibility issues to work themselves out before flipping the DIY switch.
We should add that with the GeForce 7950 GX2, Nvidia has put its ForceWare Release 90 drivers up for download on its Web site. With that driver set, you get Nvidia's new Control Panel, which gives you a more user-friendly interface for managing your display and 3D settings, similar to ATI's Catalyst Control Center software, released last year. Nvidia also claims its new software improves various video image-quality tweaks. Our resident home-theater PC guru, Dan Ackerman, is going to tackle that next week. Since the video improvements apply to all of Nvidia's 3D cards, and we don't expect many people will buy a GeForce 7950 GX2 for home theater needs, we will discuss the video improvements in their own article.
ATI test bed (ATI Catalyst 6.5 drivers)
AMD Athlon 64 FX-60 CPU, Asus A8R32-MVP Deluxe motherboard, 2GB (1GB x 2) Corsair XMS Memory, 160GB Seagate 7200.7 Serial ATA hard drive, Windows XP Professional SP2.
Nvidia test bed (ForceWare version 84.21 driver, ForceWare 91.29 driver for 7950 GX2):
AMD Athlon 64 FX-60 CPU, Asus A8N32 SLI Deluxe motherboard, 2GB (1GB x 2) Corsair XMS Memory, 160GB Seagate 7200.7 Serial ATA hard drive, Windows XP Professional SP2.