Overclocking

To 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 930 MHz core (16% overclock) and 1290 MHz Memory (29% overclock). Pretty solid overclocks! But those were to be expected given that the card is a tuned down HD 5870 GPU.

Basically there are two ways how a Cypress GPU can end up on a HD 5830:
1) It has less than 1440 usable shaders
2) It has less than 32 usable ROPs

Clock binning does not play any role here. So there is a chance that you could get a super overclocker ASIC that would usually end up on a HD 5870, but couldn't make it because of 1) or 2) or both. I expect that we see a wide range of possible overclocks ranging from 820 MHz all the way beyond 1000 MHz.

ASUS includes their SmartDoctor utility with this graphics card to support voltage changes. The maximum you can set is 1.35V, our sample managed 1000 MHz GPU clock at this voltage.

Overclocked Performance

Using these clock frequencies (930/1290) we ran a quick test of Call of Duty 4 to evaluate the gains from overclocking.


The actual 3D performance gained from overclocking is 15.1%. Nice, but still far far away from the HD 5850.

Temperatures

Temperatures are comfortably low, even with overclocking. I wouldn't be surprised if ASUS releases a new BIOS that reduces fan noise a bit at the cost of slightly increased temperatures.

Clock Profiles

Modern 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.


AMD includes their own overclocking utility with Catalyst Control Center. While easy to use, it also limits the maximum overclock to a predefined limit in the BIOS. Here are the upwards limits for overclocking CCC gives you.