Stefan Mileschin

We are indeed dealing with a refresh of the previous Hawaii XT GPU now baptized Grenada XT, featuring GCN 1.1, 6200 million transistors, 2816 shading units, 176 TMUs, 64ROPs and 44 Compute Units. The available VRAM is now 8GB instead of 4GB GDDR5 and now runs at higher frequencies than on 290X cards by default (1500MHz, 6000MHz effective); this surely helps when running multiple cards for a CrossFireX setup and using multiple monitors. Speaking of the frequencies, the defaults of the GPU on OEM cards have been raised to 1050MHz and with its pre-overclocked card HIS has added extra 20MHz.

http://www.madshrimps.be/articles/article/1000747/