Gigabyte’s first single-card SLI trick impressed us as a feat of engineering, but its performance left us cold. This time ‘round, the company’s engineers got almost everything right. The GV-3D1-68GT is not only faster than a single 7800 GTX, it’s faster than two 6800 GT cards running in conventional SLI. The only problem: This behemoth weighs as much as six Quarter Pounders!
Gigabyte’s original GV-3D1 merged two nVidia GeForce 6600 GT cores on a single card, but it was compatible only with Gigabyte’s nForce4 GA-K8NXP-SLI motherboard—and could be purchased only as part of a $495 videocard/mobo bundle. Never before or since have two eight-pipe GPU, dual 128MB, 128-bit interface videocards been so freakin’ expensive.
The GV-3D1-68GT pulls off the same engineering trick, but it pairs two much faster, 16-pipe GeForce 6800 GT cores (each running at 375MHz) and offers dual 256MB frame buffers (clocked at 500MHz and with 256-bit memory interfaces). The capper is that the new board is compatible with any nForce4 SLI motherboard.
All those components add up to some serious mass—and a need for some serious cooling: Heatsinks and fans mounted on both sides of the 10-inch-long circuit board contribute nearly two inches to its girth, and the entire package tips the scales at a staggering two pounds, 4.3 ounces (compared with 12 ounces for a standard 6800 GT card). Despite all this bulk, Gigabyte saw fit to provide just a single mounting bracket, which left the card keeling over in our mid-tower-mounted motherboard’s 16x PCI-E slot. We recommend that buyers jury-rig some additional support for this monster’s ass-end.
In fact, anyone who’s considering installing the GV-3D1-68GT in their machine should take note of all its dimensions. The heatsink on the back of the card, for instance, came into contact with the supplemental 12-volt power connector on our Asus A8N-SLI Deluxe motherboard—we had to push hard before it would seat properly—and if we were utilizing the case’s second hard drive cage, we would have run into even more problematic clearance issues. The aforementioned fans are loud—they stood out among all the other machines contributing to the Lab’s cacophony—but at least they don’t generate the type of high-pitched whine that sets your teeth on edge.
Two DVI connectors are installed on the mounting bracket, along with a video-out port. Anyone interested in editing their own analog videos should note that video-in is not supported. If you’d like to run four monitors—not in SLI mode, of course—you can plug in a second mounting bracket that’s outfitted with a pair of analog VGA connectors. The card also supports dual Dual-Link DVI, so you can drive two 30-inch Apple Cinema Displays from a single card. Just like a conventional 6800 GT card, the board draws additional power through a six-pin plug (Gigabyte provides a Molex Y cable if your power supply isn’t equipped with the appropriate cable).
As you can see from our benchmark chart, the GV-3D1-68GT handily beats the performance of both a single GeForce 7800 GTX and that of a pair of conventional GeForce 6800 GT cards running in SLI. In our test rig, the card ran Doom 3 (at 1600x1200 resolution with 4x antialiasing and 8x anisotropic filtering) nearly three frames per second faster than two 6800 GT cards, 18.5fps faster than a single 7800 GTX, and 21.8fps faster than a single 7800 GT. Not bad.
At press time, the average street price for a single GeForce 6800 GT card was about $325, so the GV-3D1-68GT’s $600 list price represents at least a $50 discount over buying two separate cards (thus overcoming our next biggest objection to its predecessor). On the other hand, you could pick up a single GeForce 7800 GTX for the average street price of $510, or a single 7800 GT for $400, and two of either of those cards in SLI will definitely leave Gigabyte’s board with a poor body image.
To be absolutely fair to Gigabyte, however, two 7800 GTX boards cost more than a grand, and two 7800 GT boards will set you back more than $800. Compared with that, $600 for a board that beats the stuffing out of either single card is a good deal. Unlike those two boards, however, the only way you can further increase your PC’s performance is to chuck this card and replace it with two more. Still, this card is a good value for the money.
+ Sly and the Family Stone
Faster than a single GeForce 7800 GTX; cheaper than two GeForce 6800 GTs.
- Sly Stallone
Morbidly obese; obnoxiously loud. Slighty more expensive than a single 7800 GTX.