So on GDDR5 vs LPDDR4, what are the pros and cons? GDDR5 has much more bandwidth. Is it more expensive as well? LPDDR4 has significant power savings, so I would expect it to be used for the handheld. Would LPDDR4 be a bottleneck for the type of Polaris that may be in the console at 1080p, even with texture compression?
I'm thinking yes, based on what we've seen from the likes of Tonga and the GTX 950/960, which use GDDR5 with similar texture compression. The 128 bit bus the 960 uses seems to bottleneck it in certain situations.
I thought latency was better on LPDDR4 while still providing "enough" bandwidth (but not as much), iirc.
Imo, not near enough for something targeting better than PS4 according to these rumours.
Say they double the chips and pinouts on that, only landing them at 50GB/s vs the 170GB/s GDDR5 in the then three+ year old PS4.
They could do a fast eDRAM pool...Then that get them to the more developer issue inducing state of the XBO. Even if they do 64MB eDRAM which will be enough for 1080p unlike where the XBO struggles, it still makes the developer think about where to put things.
If I were making it, definitely GDDR5. Or even better, Micron did say they had GDDR5X customers in Q1, not sure of the scale up.
While I'm talking, the latency factor of GDDR5 is often overstated I think, as it's longer in cycles, but since GDDR5 is also clocked much higher, it's similar in actual units of time.