As you all know Nvidia has recently launched its 8600/8500 series of affordable DirectX 10 graphics cards, and we already know a lot about their performance. We've tested some of them already, and you can find the test results in our Review section, here, here and here.

On todays menu is the most powerful of the Sub $/€200 DirectX 10 bunch, an overclocked Geforce 8600 GTS from MSI. It will be nice to see how the OC version measures up to the reference designs.

According to information available to us at the moment, all Geforce 8600 GTS cards coming directly from Nvidia work at default speeds - 675MHz core and 2000MHz memory - and they use the 60.84.18.00.06 BIOS. That particular BIOS version drew our attention while we were testing MSI's 8600 GTS OC, as we used the 60.84.18.00.08 performance BIOS with another card.

All BIOS versions we got from MSI had the ".06" designation, and so far we don't know if MSI is planning to use the performance BIOS for its overclocked cards. To clear thing up a bit, let's go back in time.

We got an MSI NX8600GTS-T2D256E-HD-OC card which operates at 690MHz core and 2100MHz memory. We thought that the core speed was misread by Nvidia's control panel, so we tried some other tools and got the same values. We were a bit confused, since MSI's product page states that the core on this particular card should work at 700MHz. After we got in touch with MSI we received a new BIOS which set the core clock at 700MHz. Soon after we got another BIOS which raised the frequency even further to 720MHz on the core and 2200MHz for the memory to be precise. At these speeds the card truly deserves the "OC" suffix which denotes overclocked version.

While we were waiting for MSI's response we got a bit curious and used the opportunity to try out the performance BIOS we got from other sources. The performance BIOS designation ends with an ".08", while the standard BIOS ends with ".06". The difference between these two versions is clear, one gets you better performance than the other. However, the performance BIOS has some memory stability issues at higher frequencies, making the choice a bit more difficult. With the ".08" we managed to overclock the MSI NX8600GTS-T2D256E-HD-OC to 785MHz core and 2174MHz memory.

It is clear that our overclocking efforts failed to reach the 2200MHz mark, the speed at which the memory works with the latest MSI BIOS.

To prove that the performance BIOS does a better job even with a lower memory clock we flashed our card using the second MSI supplied BIOS. We raised the core clock from 720MHz to 785MHz and the card worked like clockwork. At first we didn't mess around with the memory clock, but as the results didn't quite match our expectations we pushed the memory to 2220MHz. More than that we couldn't manage.

The results speak for themselves, the performance BIOS still performs better.

It's easy to see the differences. On the same clocks, or with faster memory with the .06 BIOS, the results are always one sided and the performance BIOS wins. All these results came from the same MSI card of course.

The official MSI page states that the overclocked NX8600GTS-T2D256E-HD-OC card works at 700MHz core and 2100MHz memory. We compared the .08 BIOS with the original MSI BIOS at the default 700/2100 clocks. Again, the .08 BIOS outperforms the MSI BIOS.

Quake4 is not the only game we tried out, but it shows that 46MHz higher memory clock doesn't help the .06 BIOS against the 08 performance BIOS. At the end we still have to mention the shortcomings with the 08 BIOS when it comes to memory overclocking.