ATI's Radeon X550 chip doesn't appear on the company's website, but that hasn't stopped Taiwanese vendor Info-Tek announcing a pair of graphics cards based on the part.
A mention of the X550 has also been found lurking in ATI's latest Catalyst driver, 5.6, verifying that it's a genuine ATI product.
The driver reveals the X550 is essentially a higher-clocked X300. It's based on the same core as the older chip, the RV370, with four pixel pipelines and a pair of vertex engines. While the X300 is clocked at 325MHz, the X550 comes in at 400MHz. That ups the fill rate from 1.3bn texels per second to 1.6bn.
The X550 is used in Info-Tek's Gecube Radeon HM550 and Gecube Radeon X550 PCIe boards. Both have 128MB of on-board memory but use ATI's HyperMemory technology to grab extra buffer space from the host PC's main memory bank. The HM550 uses a 64-bit memory bus, the other card a 128-bit one. They support video resolutions of up to 2048 x 1536.
Hong Kong's HIS has also announced an X550-based board, the HIS X550 iFan, again with 128MB of on-board DDR SDRAM, clocked to 500MHz and operating across a 128-bit bus. HyperMemory expands the total memory available to the GPU to 256MB. Once more, the maximum supported resolution is 2048 x 1536. The board uses HIS' low-noise active cooling system. ®