PowerColor HD 6870 PCS+ is a special version of Radeon HD 6870 card that comes factory overclocked and strapped with special cooling.
Just a reminder – at the end of October 2010, AMD launched two new graphics cards from its Northern Islands family Radeon HD 6870 and HD 6850 cards. Radeon HD 6870 beats the Radeon HD 5850 but it is slower than Radeon HD 5870.
PowerColor overclocked it HD 6870 PCS+ card as you can see from the GPUZ screenshot.
The Barts XT, known as the HD 6870 card, has 14 SIMDs, with 80 Stream Processor per SIMD (total of 1120 Stream Processors) and 56 texture units (TMUs). As noted it has a 256-bit GDDR5 memory interface and comes with 32 Raster Operation Processors (ROPs). The fully enabled Barts, or the Barts XT, has 2TFLOPS of computational power. The reference Barts XT GPU ended up clocked at 900MHz for the GPU and 4200MHz for 1GB of GDDR5 memory paired up with a 256-bit memory interface.