Sapphire Pure Innovation PI-A9RX480 mobo
Overclocker's dream - or too expensive?
The Achilles Heel of the SB400 South Bridge strikes again, unfortunately. SB450 USB 2.0 performance is still lacking when compared to its rivals', and Sapphire suffers as a result. ATI informs us that it intends to resolve the USB 2.0 'issue' in the next iteration of IXP South Bridges. We certainly hope so. Pure performance, which thus far has been good, is only one facet of the motherboard decision-making process.
Overclocking was undertaken by dropping the HyperTransport frequency to 600MHz, RAM to DDR200 at 200MHz HTT, an AMD Athlon 64's FX-55 multiplier down to 6x, and, finally, North Bridge voltage up to 1.32V. No additional cooling was directed at the board and basic stability was determined by running a full loop of 3DMark2001SE without corruption or failure.
Standard stability was achieved at 305MHz HTT. The North Bridge became rather toasty, running at between 75-80²C, although, as mentioned, stability remained unaffected. Adding in a touch more NB juice and installing a 120mm fan directed at the NB, we were able to inch it up a little higher.
Note quite the highest, stable HTT speeds we've seen, but well above average for Socket 939 mainboards, and extremely promising for the slew of CrossFire-compatible boards that we're undoubtedly be seeing in the near future.