Review: Overclocking the Radeon HD 4890 to 1GHz @ Anandtech

[WiCKeD]

Anandtech explores overclocking on the newly released HD 4890, benefits in games from core/memory increases and showcases its performance.

Adjusting core clock speed has a much higher impact on performance than only adjusting memory speed. At stock clock speeds the 4890 is much more compute bound than memory bound, and this is where the difference comes in. While the 900MHz core clock variant will not offer huge performance gains over the stock card, the performance gains will be fairly proportional to the clock speed increase.

Despite the fact that a 50MHz bump only offers a maximum potential average performance improvement of about 6%, we often see realized performance gains of between 3% and 5% on 900MHz core clocked 4890 hardware. This is certainly a much better return than we saw even with a 23%+ memory overclock. Even so, 5% real world performance isn't the holy grail. So we decided to test multiple core clock frequencies ranging from 850MHz to 1000MHz in 50MHz increments.
...
In non-CPU limited situations, the approximately 10% to 13% performance improvement out of a potential 17.6% improvement is nothing to sneeze at.

Full Article @ Anandtech