Overclocking The Radeon HD 4890
For our next set of performance metrics, we spent some time overclocking the new Radeon HD 4890 using the Overdrive utility built into ATI's Catalyst drivers.
Using the auto-tune utility built right into the Overdrive tab, we were very easily able to take the reference Radeon HD 4890 (Asus EAH4890) up from its default CPU and Memory clock speeds of 850MHz and 975MHz, respectively, to an impressive 975MHz and 1035MHz. With the card overclocked, we re-ran a couple of benchmarks and saw significant performance improvements, as you might expect. The framerate in our ET:QW benchmark went up by 7.9 FPS (8.8%) and our L4D result increased by 8.74 FPS (10%). With this kind of headroom in a reference cards, we're eager to see what some board parters are able to do with custom designs that feature more elaborate cooling solutions.
We should also point out that Asus' Radeon HD 4890 offerings also include a copy of the company's SmartDoctor Utility that gives uses the ability to tweak voltages for even better overclocks. We weren't able to test SmartDoctor here due to time constraints, but suspect GPU speeds in excess of 1GHz are possible with some additional effort.