Thanks to Sporran.
On the ESRAM:
On ESRAM bandwidth number:
On balancing the GPU:
On GPGPU:
http://www.eurogamer.net/articles/digitalfoundry-vs-the-xbox-one-architects
If you guys find something more interesting, throw it up and I'll add to the OP, obviously keeping the word count of quoted text to a minimum.
On the ESRAM:
Leadbetter said:"If you're only doing a read you're capped at 109GB/s, if you're only doing a write you're capped at 109GB/s," he says. "To get over that you need to have a mix of the reads and the writes but when you are going to look at the things that are typically in the ESRAM, such as your render targets and your depth buffers, intrinsically they have a lot of read-modified writes going on in the blends and the depth buffer updates. Those are the natural things to stick in the ESRAM and the natural things to take advantage of the concurrent read/writes."
On ESRAM bandwidth number:
The same discussion with ESRAM as well - the 204GB/s number that was presented at Hot Chips is taking known limitations of the logic around the ESRAM into account. You can't sustain writes for absolutely every single cycle. The writes is known to insert a bubble [a dead cycle] occasionally... one out of every eight cycles is a bubble so that's how you get the combined 204GB/s as the raw peak that we can really achieve over the ESRAM. And then if you say what can you achieve out of an application - we've measured about 140-150GB/s for ESRAM
On balancing the GPU:
Leadbetter said:Every one of the Xbox One dev kits actually has 14 CUs on the silicon. Two of those CUs are reserved for redundancy in manufacturing, but we could go and do the experiment - if we were actually at 14 CUs what kind of performance benefit would we get versus 12? And if we raised the GPU clock what sort of performance advantage would we get? And we actually saw on the launch titles - we looked at a lot of titles in a lot of depth - we found that going to 14 CUs wasn't as effective as the 6.6 per cent clock upgrade that we did."
On GPGPU:
Leadbetter said:Microsoft's approach to asynchronous GPU compute is somewhat different to Sony's - something we'll track back on at a later date.
http://www.eurogamer.net/articles/digitalfoundry-vs-the-xbox-one-architects
If you guys find something more interesting, throw it up and I'll add to the OP, obviously keeping the word count of quoted text to a minimum.