Linux Overclocking Software

On the other side of the table, the overclocking situation for ATI/AMD on Linux is much gloomier. The ATI Windows Catalyst display drivers support GPU/memory overclocking and there is a host of third party utilities available, but the situation isn't the same when it comes to the fglrx drivers and overclocking. At this time the fglrx drivers do not allow the end-user to overclock their graphics card. However, it is worth mentioning that in the 8.26.18 drivers an OverDrive state had appeared in aticonfig for PowerPlay. The third party utility available for ATI graphics cards under Linux is Rovclock. Rovclock is maintained by Sebastian Witt, and unfortunately is not nearly as extensive as NVClock. Rovclock 0.6e only offers a command-line interface with a very limited set of options. The options available are for setting the core clock, memory clock, xtal frequency, and memory timings. Another shortcoming with this project is only the Radeon 7500 series through the Radeon X800 series is supported. There remains no support as of yet for the X1000 series -- the R300 support for Rovclock was only delivered earlier this year.

ATI Radeon X300 Series

Radeon overclock 0.6e by Hasw ([email protected])

Found ATI card on 01:00, device id: 0x5460
I/O base address: 0x2000
Video BIOS shadow found @ 0xc0000
Reference clock from BIOS: 27.0 MHz
Memory size: 65536 kB
Memory channels: 0, CD,CH only: 0
tRcdRD: 5
tRcdWR: 3
tRP: 5
tRAS: 10
tRRD: 3
tR2W-CL: 3
tWR: 5
tW2R: 2
tW2Rsb: 1
tR2R: 2
tRFC: 17
tWL(0.5): 2
tCAS: 4
tCMD: 0
tSTR: 1
XTAL: 27.0 MHz, RefDiv: 9

Core: 297.0 MHz, Mem: 229.50 MHz

ATI Radeon X1800 Series

Radeon overclock 0.6e by Hasw ([email protected])

Found ATI card on 06:00, device id: 0x7100
I/O base address: 0x5c00
Video BIOS shadow found @ 0xc0000
Invalid reference clock from BIOS: 0.0 MHz
Memory size: 262144 kB
Memory channels: 0, CD,CH only: 0
tRcdRD: 3
tRcdWR: 1
tRP: 3
tRAS: 6
tRRD: 1
tR2W-CL: 1
tWR: 1
tW2R: 0
tW2Rsb: 0
tR2R: 1
tRFC: 13
tWL(0.5): 0
tCAS: 0
tCMD: 0
tSTR: 0
XTAL: 27.0 MHz, RefDiv: 13

Core: 0.15 MHz, Mem: 0.0 MHz

Outside of NVIDIA and ATI for video card overclocking, gMGA clock is available for overclocking the Matrox G400 and GlideControl can overclock 3Dfx Voodoo cards (if you still have any of them laying around). No Linux speed utilities are available for XGI Volari graphics cards. Outside of video card overclocking, Powertweak was an open-source utility that was working on CPU voltage/speed adjustment abilities, but unfortunately this program has not seen a release in over three years. One program that supports VCore, Vdimm, and Vagp adjustments is 8rdavcore, which is specific to Epox EP-8RDA series motherboards. Unfortunately, that is about it when it comes to software utilities to aide in overclocking under GNU/Linux. If you are interested in under-clocking your ATI GPU for power or cooling conservation, the fglrx drivers support PowerPlay and dynamic clock functionality also works with the open-source Radeon drivers. For CPU under-clocking, cpufreq supports Enhanced Intel SpeedStep Technology (EIST) as well as AMD Cool 'n' Quiet.

If you have come across any other Linux overclocking utilities, be sure to share your experiences over at the Phoronix Forums.