When ATI, the graphics division of AMD, first launched the Radeon HD 4890 video card at the beginning of April, we noted that the RV790 core it uses had a few tweaks in it. It is a respin of the original RV770 silicon, with retrained and rearchitectured power paths for greater power efficiency. We also noted that ATI engineers also used decoupling capacitors in a decap ring to increase signal integrity.

This enabled ATI to boost the core clock to 850MHz, up 100MHz from the Radeon HD 4870, but several reviewers were already overclocking the board up close to 1GHz using stock cooling for an additional performance boost.

Now, ATI and its Add-In Board partners are shipping factory overclocked graphics cards set at 1GHz, the first to break the 1GHz barrier using standard air cooling solutions. This enables the GPU to achieve 1.6 TeraFLOPs, a large jump over the 1.35 TeraFLOPs of the stock Radeon 4890. The GDDR5 memory may also be clocked higher, depending on the board partner.

The RV790 dies are tested after production at TSMC, and binned based on ATI's series of quality assurance tests. The highest performing chips are set at 1GHz for use in the new cards. AMD does warn that "damage caused by overclocking AMD’s GPUs above factory-set overclocking is not covered by AMD’s product warranty, even when such overclocking is enabled via AMD software".

Interestingly, AMD was the first to ship 1GHz CPUs back in March of 2000. It was the mighty Athlon built on a 0.25 micron process that bested the Pentium III.

Although most games will see a boost in performance, games using DirectX 10.1 such as S.T.A.L.K.E.R: Clear Sky and Tom Clancy’s H.A.W.X. should see an additional boost due to optimizations already present in the hardware.

General purpose GPU-accelerated Stream applications such as video transcoding and post processing should also see a jump in performance, as will OpenCL applications.


Radeon HD 4890 1GHz cards announced or shipping:

ASUS EAH4890 Formula
PowerColor PCS++ HD4890
Sapphire HD 4890 Atomic Edition
XFX’s ATI Radeon HD 4890 Black Edition