Overclocking

Overclocking can be performed in a few ways for the X850 XTPE. The first is the way many normal (non-enthusiast) end users will try. This is using Overdrive version 3 within the catalyst drivers.

To begin overclocking with overdrive you first need to unlock the card. This is performed by clicking the padlock at the top right of the overdrive tab. Once unlocked the drivers report this, even after a reinstall of the drivers.

You can see from the screenshot above that the card reports the core speed and temperature along with the memory speed. You can also select to use the enchanced clocks for 3D only, and to apply the settings at start-up. When you’ve decided which options you wish to use you can overclock in 2 ways. The first is to manually overclock by moving the sliders on the left of the tab to the desired settings. Very easy.

Equally as easy is the automated clock configuration utility. When run the system tests various clock speeds for artefacts. The utility will then report back the recommended enhanced clocks to you and allows you to apply them.

When we ran the utility on our system Overdrive found the maximum safe settings to be 580mhz core and 600mhz memory. So a 40mhz increase in core speed over stock and 10mhz memory.

In order to find our maximum overclock manually we turned to Powerstrip. It has been our preferred overclocking tool for sometime and never fails us. Using Powerstrip we found the maximum clocks to be 621mhz core and 621mhz memory. We were able to run 625core and 630 memory for a while without issue however eventually some artifacting did occur.

Here's how the overclock affected our performance in a few tests.

Doom3 1600x1200 High/4xAA	FPS
X850 XTPE @ 540/590	44.2
X850 XTPE @ 621/621	48.4

CS:Source VST 1600x1200 4xAA 16xAF	FPS
X850 XTPE @ 540/590	98.83
X850 XTPE @ 621/621	110.10

Synthetic/Theoretical performance.

Before we conclude, for those who are interested, here are the results we obtained from Shadermark 2.1 when running the X850XTPE through the standard benchmark.

Next: Conclusion