Advanced Micro Devices on Tuesday officially confirmed existence of two new graphics cards that will serve performance-mainstream market. While the new boards seem to offer decent performance, they will be available for a limited time in limited quantities. Still, the new products will inevitably slowdown the possible demand towards dual-chip graphics gars from AMD’s partners.

“AMD is excited to announce the newest member of its flagship ATI Radeon HD 2900-series, the ATI Radeon HD 2900 Pro. The ATI Radeon HD 2900 Pro features the powerful next-generation unified shader architecture with 320 unified stream processors, comprehensive DirectX 10 support and built-in HDMI multimedia features for an immersive HD gaming experience,” a statement by AMD reads.

Unlike expected previously, the ATI Radeon HD 2900 Pro graphics card features the same fully-fledged ATI R600 graphics processor with 320 unified shader processors (SPs), 16 texture units (TUs), 16 render back ends (RBEs) and 512-bit memory controller, but clocked at 600MHz instead of 742MHz on the HD 2900 XT model. The Radeon HD 2900 Pro also retains 512-bit memory bus and can come equipped with 512MB or 1GB of GDDR3 memory clocked at 1600MHz, just a little down from memory frequency of HD 2900 XT models.

AMD’s partners will sell ATI Radeon HD 2900 Pro 512MB for $249, whereas the model with 1GB of memory will have manufacturer suggested retail price of $299. It is interesting to note that some 1GB versions will have print-circuit boards with 12” length that may not fit into mainstream computer cases.

“The ATI Radeon HD 2900 Pro is available today on a limited basis subject to supply constraints,” AMD stressed in its short press statement.

AMD has been criticized for quite some time for having a gap in its DirectX 10 lineup between $179 and $399 price-points on which the company responded that its partners will sell dual-chip ATI Radeon HD 2600 X2 graphics cards for about $249 to fight Nvidia’s GeForce 8600 GTS. But now that AMD’s partners started to sell the HD 2900 Pro for $249, it will not only distract attention from the lower-performance Radeon HD 2600 X2 (in fact, even two Radeon HD 2600 chips have only 240 unified shader processors compared to HD 2900’s 320 units), but will also cause some potential ATI Radeon HD 2900 XT buyers to change their minds, as the XT model has just a slight performance advantage over the Pro.

Typically, add-in-board partners would hardly be happy with a product that does not fit into the current lineup, however, this does not seem to be the case with the ATI Radeon HD 2900 Pro, as it is an extremely limited edition offering.

“The HD 2900 Pro is not something AMD needs. Those are just ‘defective’ graphics cards [that could not run at 742MHz’ and there are very few of them, just about several thousands worldwide. In fact, we only accepted orders [on them] for several days,” said a representative of an add-in card supplier who wished to remain unnamed.