Single page Print

Ganging up: The GTX 295


Inside of this quintessentially Cash-meets-Vader cooling shroud is a pair of circuit boards, each of which has mounted on it a GT200b GPU and associated memory. Like so:


A mock cutaway of the GeForce GTX 295. Source: Nvidia.

This is how Nvidia likes to do its multi-GPU graphics cards, dating all the way back to the GeForce 7950 GX2. Somewhere in there is a PCI Express switch chip that allows two GPUs to share a single PCIe x16 slot.

What you get from the GTX 295 is not quite as much computing power as a pair of GeForce GTX 285 cards. All 240 stream processors are intact on each GPU, but one ROP partition is deactivated. As a result, each GPU can output 28 pixels per clock rather than 32, with a corresponding drop in antialiasing power. Also, because ROP partitions have memory controllers in 'em, each GPU has a 448-bit aggregate path to memory and 896MB of RAM instead of a full gigabyte. Many of these numbers will no doubt sound familiar if you know about the GeForce GTX 260, which also has one of its ROPs deactivated.

Why the gimpy GPU? Many reasons: to keep chip yields up and costs down, to reduce the power envelope, to make everything fit into a small space, or because it somehow makes sense. Yes, it's a little weird that the GTX 295 has 1792MB of GDDR3 memory onboard. Doesn't really matter, though, at the end of the day. The GTX 295 will be plenty potent with a pair of GPUs in this configuration—to say the least.


Yep, the 295 does indeed require an 8-pin PCIe power connection in addition to a 6-pin. That's pretty much a foregone conclusion. The connector you might not have been expecting, though, is the HDMI port on the back (or is it front?) of the card, which replaces the analog video output. Only makes sense, I suppose. The other connector of note is a single SLI interface, which protrudes from the top of the card, threatening quad SLI.


Despite its dually nature, the GTX 295 is still only 10.5" long. Well, "only" is a strong word, but let's say the 295 is no longer than the 285 or the Radeon HD 4870 X2, which is nice. GTX 295 cards like this one seem to be selling right now for a prevailing price of $499. That's a whole heck of a lot of money, and you'll presumably be using it with a pricey 30" LCD monitor or something similar. Otherwise, there's little point to a video card that costs half a grand.

Not that Nvidia isn't trying, of course. The firm helpfully points out that the GTX 295's dual GPUs can either pair up for peak graphics power or be split so that one card handles graphics duties and the other does PhysX calculations. We're still a fair distance from the day when an entire GT200b GPU is best used for physics, though. We do have a copy of Mirror's Edge for the PC, which has been fortified with additional PhysX vitamins and minerals, and we plan to have a look at it very soon.