How to Silence a Radeon HD 4870 or 4890

Additional details and conclusion

We have of course extensively tested the card once modified and the temperature of the card remained stable even though the temperature of the room was artificially increased. We have also pushed the clock speed of the Radeon HD 4890 from 950 MHz to 950 MHz for the GPU and from 975 MHz to 1100 MHz for the VRAM. The card remains stable too, but we have modified the cooling procedure in the BIOS thanks to the Windows tool Radeon Bios Editor requiring the original BIOS of the card. But this is another story.

Without overclocking the card, you will benefit at default clock speed from the excellent performance level of the card while having it now as silent as the Mac Pro. With such a beast in your Mac Pro you will be running all games at max specifications without much problem, as well as using all GPU-demanding Pro applications. You will also have a good GPU to handle Snow Leopard and its Grand Central and Open CL.