PowerColor HD 6850 PCS+ is a special version of Radeon HD 6850 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. Radeon HD 6870 and HD 6850 are not high-end cards but rather products made with medium budget in mind, so called Gamers’ sweet spot cards.
PowerColor overclocked its HD 6850 PCS+ card as you can see from the GPUZ screenshot. Clock speed is 820 MHz and 1100 MHz memory, which is 6% more on core and 10% more on memory compared to reference clocks.
The Barts PRO is quite similar to the Bart XT except, of course, for the fact that it has two SIMDs less, or simply, it has 48 Texture Units (TMUs) and 960 Stream processors. 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).
Bart PRO ended up clocked at 775MHz for the GPU and 4000MHz for 1GB of GDDR5 memory paired up with a 256-bit memory interface.