HIS Radeon HD 5850 1GB video card review
 

While a reference Radeon HD 5870 makes use of a full Cypress core with all of its Stream Processors, texture units, ROPs and so on intact, the Radeon HD 5850 finds itself with a reduced unit count in some areas, with AMD making the most of the redundancy built in to a modern graphics core to allow them to sell parts that would otherwise not be fully functional. This means that all Radeon HD 5850 cores have two of their SIMD arrays disabled, to leave the board with 1440 Stream Processors, while this reduction also removes two texturing units with it to leave this part with eighteen texturing units to match its SIMD count. Clock speeds are also reduced for this SKU, with an 850MHz core clock speed on the Radeon HD 5870 becoming a 725MHz core clock on the Radeon HD 5850, while the 1GB of GDDR5 memory utilised by both boards sports a 1000MHz clock here against 1200MHz for the higher performance part.

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