We know about Haswell’s massive shader count, and we know why it has them, but what is Crystalwell exactly? The answer is simple, really wide DRAM on the package, not that fast, but more than wide enough to make up for it.
SemiAccurate’s sources are now saying that Crystalwell bearing Haswell GT3s use a DRAM variant, likely DDR3 or LP-DDR3, for their memory. That memory, referred to eDRAM, although not in the classic sense of, “IBM can’t fab that chip at economically viable yields because they use….” type eDRAM, it is not on the same die. Crystalwell puts custom designed DRAM on an interposer with a 512-bit wide data path to the CPU/APU.
If that memory is a low power DDR3/1066 variant, a 512-bit wide data path give it the same bandwidth as 128-bit wide GDDR5 running at a bit over 4GHz. If Intel slaps 1GB of that memory on Haswell GT3, you are looking at the same ballpark memory capabilities as a mid-range GPU. It goes without saying that this blows any integrated GPU out of the water in that regard, Trinity included. This memory will open up new vistas for the user to marvel at how awful the Intel drivers are, how broken their release schedule is, and do it at great speeds.S|A