OverclockingTo find the maximum overclock of our card we used a combination of GPUTool and our benchmarking suite.
The overclocks listed here were achieved with the default fan and voltage settings as defined in the VGA BIOS. Please note that every single sample overclocks differently, that's why our results here can only serve as a guideline for what you can expect from your card.
The overclocks of our card are 770 MHz core (10% overclock) and 1048 MHz Memory (13% overclock).
Overclocks are not very spectacular, but decent, considering that we used the stock cooler. With more extreme forms of cooling and voltage increases I'm sure there will be quite a bit more headroom.
I would also like to point out that the shader clock is locked to the core clock in a ratio of 2:1. Whether this is a limitation of the current driver or a limitation of the clock design is not known yet.
Overclocked PerformanceUsing these clock frequencies we ran a quick test of Call of Duty 4 to evaluate the gains from overclocking.
The actual 3D performance gained from overclocking is 8.5%.
A Radeon HD 5870 overclocked to 1000 / 1370 reaches 132.3 FPS in the same test.
While idle temperatures are OK, load temperature is close to what I would consider a limit for any graphics card.
Due to NVIDIA's fan profile in the BIOS, the card will reach 96° maximum at which point the fan speed will ramp up some more to bring the card down to 91°. My guess is that at 90° the fan would slow down again, but it never reaches that level while load is applied. This is also the reason why overclocking does not increase the temperatures any further, the fan goes up to 96°, spins faster and stays at that speed.
Clock ProfilesModern graphics cards have several clock profiles that are selected to balance power draw and performance requirements.
The following table lists the clock settings for major performance scenarios and the GPU voltage that we measured. We measure on the pins of a coil or capacitor near the GPU voltage regulator.
Desktop clocks are not a typo, based on all data we have, these are the clock speeds the card is running.
|Desktop||50 MHz||68 MHz||101 MHz||0.96 V|
|Blu-Ray Playback||405 MHz||162 MHz||810 MHz||0.99 V|
|3D Load||700 MHz||924 MHz||1400 MHz||0.99 V|