|ASUS EAH4870 DK TOP 512MB Video Card|
|Reviews - Featured Reviews: Video Cards|
|Written by Matt Williams|
|Sunday, 21 December 2008|
Page 13 of 15
ASUS HD 4870 Overclocking
The EAH4870 DK Top comes from ASUS already overclocked, but that wasn't good enough for us. Most manufacturers leave a certain margin of safety when establishing factory overclocking speed. This ensures that more cards will be capable of sustaining the set clock speeds and cuts down on warranty service due to failed overclocks. We decided to explore this margin, and after some stability testing, settled on 855MHz for the GPU core and 1175MHz (4700MHz effective) for the memory. Needless to say, this card had considerable headroom left, even on top of the factory overclocking performed by ASUS. To make things interesting, we also ran these benchmarks at reference HD 4870 speeds to test ASUS' claim of a 9% performance increase.
With 3DMark06 as our measure, we see roughly a 5% increase in performance with the EAH4870 DK Top over reference 4870 clock speeds. By overclocking the EAH4870 beyond the factory speeds, we were able to achieve a total increase of 12% in the SM 2.0 tests and 10% in the SM 3.0 tests.
After upping the resolution and enabling some post processing , the results became even more pronounced. The ASUS overclock yielded a 6-7% increase over reference, while our additional overclocking brought this up to a 16-17% lead.
To supplement our synthetic testing with 3DMark06, we fired up our favorite Crysis benchmarking tool and got to work. Here we see the 9% performance increase that ASUS claims in their advertising, as well as a 15-16% increase when using our own overclocking. I'm sure ASUS would love to stick the latter figure on their box, but I appreciate conservative, honest advertising. Overall, these are excellent overclocking results and, while we don't have specific figures in this review, the overclocked EAH4870 DK Top is definitely reaching towards GTX 280 performance.