Before You Throw Away That Busted Graphics Card

This past weekend, my four-year old graphics card, an NVIDIA GeForce 8600 GT, finally got busted. Well, it was not totally dead. As a matter of fact, it still receives power and its fan works well. It can still output video, however, not without an annoying pattern of fractals as if I was watching The Matrix’s closing credits.

At first, I thought of disposing the card and buying a replacement, but something hit my mind: I still have another GeForce 8600 GT card in my artillery and that one works as good as brand new. Instead of immediately replacing the defective 8600 GT, what came into my mind was, “what if I would try putting up an SLI setup in which one of the cards works fine and the other does not? Will it work?”.

Without further ado, I proceeded on conducting my experiment with the two GeForce 8600 GT cards. While both of them have the same GPU onboard, do take note that the defective one is factory overclocked and comes with a larger cooler. For the test, the system was composed of the SLI-capable Gigabyte G1.Sniper 2 motherboard, Intel Core i5-2500K processor, two 4GB Kingston DDR3-1600 memory modules, LG Flatron D2342P 3D monitor, and an AcBel 1000 Watts PSU, with Windows 7 Ultimate 64-bit as operating system.

The two GeForce 8600 GT graphics cards were mounted on the motherboard. The faultless yet vanilla card occupied the first PCI-Express x16 slot, whereas the defective one filled up the second slot, resulting in an 8x/8x SLI combination. In my setup, I preferred using a hard SLI bridge rather than the more common tape type. I hooked up the monitor to the first card, booted up the system, and reached Windows’ desktop without any issues. The next course of action was to ensure that the cards are both detected and will run in SLI mode.

To make sure that the system senses the presence of the GeForce 8600 GT cards, I checked out Windows’ Device Manager and saw there that both cards were seen and their drivers were properly installed. GPU-Z and NVIDIA’s Control Panel further confirmed that they were up there and running.

Of course, such a setup would be useless if it was unstable. So, to convince myself that I really got it right, I put the cards to the test using the following benchmarks: PCMark 7’s Entertainment Suite, PCMark Vantage’s Gaming Suite, and 3DMark Vantage. I never expected the combination to be as powerful as today’s midrange offerings, nonetheless, the tests finished up smoothly, minus the fractals.

Like what the aforementioned applications and benchmarks suggest, a working and a defective graphics card can work together in an SLI configuration. However, I stress out that it was simply an experiment and results under different settings may vary depending on the gravity of the graphics card’s defect, GPU involved, or the type of multi-GPU setup (CrossFireX or SLI). Importantly, it is not advisable as the condition of a failing graphics card will eventually worsen or may affect the working card’s performance in the long run.

But for those adventurous, who already tried this at home, feel free to share with us your experiences and thoughts.