XFX R7850 Core Edition 1GB Review - PAGE 3

AMD's Pitcairn GPU is manufactured using a 28nm process with a total transistor count of 2.8 billion. The XFX R7850 contains 16 CU's, 1024 SP's (Stream Processors), 64 Texture Units, 32 ROPs and 1GB of GDDR5 memory. Core and memory clocks are 860MHz and 1200MHz, respectively. The card has a maximum Powertune limit of 150W and a average power draw around 130W and a minimum of 10W when idle.

The XFX R7850 has a total of 8 Elpida memory IC's (#W1032BBB6) with a maximum data rate of 5Gbps, leaving very little room for overclocking the memory. AMD has placed the R7850's power circuits at the rear of the PCB, as this seems to be the trend with smaller PCB's nowadays.

XFX's IP-5X fan is paired with a densely packed fin array and outfitted with a dual-heat pipe running through the copper cooling block. Overall the design performs extremely well when operating the R7850 at stock speeds, but quickly succumbs to heat generated from overclocking the core and memory.

Overclocking:

Overclocking the XFX R7850 proved to be a bit of a challenge due to the aforementioned cooling capabilities of the card. Starting with basic steps, I began increase the core clock 10MHz at a time until it failed to pass Unigine's Heaven 3.0 benchmark, at which time I increased the voltage by increments of 5 until it passed "Rinse & Repeat". This led to a stable overclock of 1035MHz core and 4948MHz on the memory, which required a voltage setting of 1.125v.

The XFX R7850's stock pixel fill-rate, texture fill-rate and bandwidth are 27.5 GPixel/s, 55.0 GTexel/s and 153.6GB/s respectively. As we increased the clock speeds, these reached 33.1 GPixel/s, 66.2 GTexel/s and 158.3 GB/s