jp (jipe4153.delete@this.gmail.com) on July 27, 2012 7:08 am wrote:
> The idea that it's easier to
> squeeze more theoretical performance with multi-threading and SSE instructions
> on a CPU is unfortunately not true.
>

I agree, but the question is if the superior programmability and better performance in some branching and data irregular workloads (and maybe most importantly, more consistent performance across many workloads), together with Intel's growing process technology advantage and maybe also advanced packaging (such as TSV stacking of DRAM to enable very high memory bandwidth for SIMD applications) will turn out to be the killer advantages of the CPU.

My answer is yes, not least because of the many historical precedents where an opportunity to eliminate a co-processor at the expense of raw performance and complexity, and to the benefit of consistency and programmability/flexibility, has been pursued with a great deal of enthusiasm by the industry. Let's not forget that the origins of the GPUs lay in their ability to accelerate 3D graphics when the CPU was no longer enough. They are not a natural, inescapable feature of general-purpose computing.

And for large-scale HPC deployments, we have already seen that throughput-optimized CPUs are (at least for the moment) preferred by the most demanding customers and that they can deliver significantly higher efficiency than CPU + GPGPU systems even with regard to peak theoretical performance, not to speak of the performance that will realistically actually be achieved.