While computer enthusiasts are generally optimistic about overclocking prospects of ATI Technologies’ latest visual processing unit (VPU) RADEON X1800 XT, such optimism may be too early, as in order to boost the clock-speeds of their RADEON X1800 XT-based graphics cards manufacturers have to use new designs of print circuit boards.

ATI Technologies recently allowed its partners to overclock the RADEON X1800 XT 512MB products from stock-speeds of 625MHz/1500MHz for VPU/memory to 700MHz/1600MHz frequencies. However, it seems that for the reasons of stability the manufacturers have to use newer print circuit boards (PCBs) revision 109-A52031-20 that has slightly redesigned power supply circuits with more MOSFETs. Besides, graphics cards makers have to utilize new BIOS versions that push up voltages and apply some other changes.

 
RADEON X1800 XT with 109-A52031-20 PCB

So far only ASUSTeK Computer, HIS and Sapphire Technologies have formally introduced the RADEON X1800 XT-based graphics cards with substantially increased clock-speeds. A source familiar with Sapphire Technologies’ products said that “current owners” of the RADEON X1800 XT 512MB graphics cards would be happy if they flash their current cards and see performance increase due to overclocking. However, the source stressed that Sapphire would not change “anything the user has”, but customers are likely to download and flash those BIOS versions on typical graphics cards. Sapphire, on the other hand, would “not give a guarantee one these cards”.

RADEON X1800 XT with 109-A52031-10 PCB

The original RADEON X1800 XT 512MB graphics cards built onto 109-A52031-10 PCBs are not good overclockers in general: the chips hardly work even at 660MHz. Flashing a new BIOS and increasing voltages will allow higher overclocking potential, the older PCB revision is not designed to handle such voltages, hence, overclocking may affect stability and lifespan of the product.

The overclocked RADEON X1800 XT 512MB graphics cards were meant to replace NVIDIA’s GeForce 7800 GTX 512 on top of the hill.