When AMD first launched the Radeon HD 2600 XT, we were told that versions of the card with GDDR3 memory would have an 800MHz memory clock. Cards are now available on the market, but with the exception of factory "overclocked" models, 700MHz seems to be the memory clock of choice. In fact, every stock-clocked Radeon HD 2600 XT GDDR3 on sale at Newegg—including models from HIS, MSI, Asus, and Powercolor—features a 700MHz memory clock.
When asked whether the memory clock spec for the Radeon HD 2600 XT GDDR3 had changed, AMD provided the following response:
“The HD 2600XT GPU and its GDDR3 reference design are qualified at 800MHz memory speed. Partners are encouraged to follow the reference design. We do allow our AIB partners to manage their own specifications to some degree including memory configuration. Our AIB partners compete with one another so it is in their interest to have competitive performance and specs.”
Graphics card makers juggle clock speeds all the time, particularly on budget models. However, when everyone seems to have settled on the same slower, 700MHz memory clock, one has to wonder exactly how competitive performance and specs have anything to do with it.
The bottom line is that the Radeon HD 2600 XT GDDR3's memory clock is effectively 100MHz lower than AMD claimed at the product's introduction. Caveat emptor.