I see my statements the other day caused more of a stir than I had intended. I saw threads locking down as fast as they pop up, so I apologize for the delayed response.
I was hoping my comments would lead the discussion to be more about the games (and the fact that games on both systems look great) as a sign of my point about performance, but unfortunately I saw more discussion of my credibility.
So I thought I would add more detail to what I said the other day, that perhaps people can debate those individual merits instead of making personal attacks. This should hopefully dismiss the notion I'm simply creating FUD or spin.
I do want to be super clear: I'm not disparaging Sony. I'm not trying to diminish them, or their launch or what they have said. But I do need to draw comparisons since I am trying to explain that the way people are calculating the differences between the two machines isn't completely accurate. I think I've been upfront I have nothing but respect for those guys, but I'm not a fan of the mis-information about our performance.
So, here are couple of points about some of the individual parts for people to consider:
• 18 CU's vs. 12 CU's =/= 50% more performance. Multi-core processors have inherent inefficiency with more CU's, so it's simply incorrect to say 50% more GPU.
• Adding to that, each of our CU's is running 6% faster. It's not simply a 6% clock speed increase overall.
• We have more memory bandwidth. 176gb/sec is peak on paper for GDDR5. Our peak on paper is 272gb/sec. (68gb/sec DDR3 + 204gb/sec on ESRAM). ESRAM can do read/write cycles simultaneously so I see this number mis-quoted.
• We have at least 10% more CPU. Not only a faster processor, but a better audio chip also offloading CPU cycles.
• We understand GPGPU and its importance very well. Microsoft invented Direct Compute, and have been using GPGPU in a shipping product since 2010 - it's called Kinect.
• Speaking of GPGPU - we have 3X the coherent bandwidth for GPGPU at 30gb/sec which significantly improves our ability for the CPU to efficiently read data generated by the GPU.
Hopefully with some of those more specific points people will understand where we have reduced bottlenecks in the system. I'm sure this will get debated endlessly but at least you can see I'm backing up my points.
I still I believe that we get little credit for the fact that, as a SW company, the people designing our system are some of the smartest graphics engineers around – they understand how to architect and balance a system for graphics performance. Each company has their strengths, and I feel that our strength is overlooked when evaluating both boxes.
Given this continued belief of a significant gap, we're working with our most senior graphics and silicon engineers to get into more depth on this topic. They will be more credible then I am, and can talk in detail about some of the benchmarking we've done and how we balanced our system.
Thanks again for letting my participate. Hope this gives people more background on my claims.