GPGPUs

[Atash]

On Friday, 16 August 2013 at 12:18:49 UTC, Russel Winder wrote:
> On Fri, 2013-08-16 at 12:41 +0200, Paul Jurczak wrote:
> […]
> Today you have to download the kernel to the attached GPGPU 
> over the
> bus. In the near future the GPGPU will exist in a single memory 
> address
> space shared with all the CPUs. At this point separately 
> downloadable
> kernels become a thing of the past, it becomes a 
> compiler/loader issue
> to get things right.

I'm iffy on the assumption that the future holds unified memory 
for heterogeneous devices. Even relatively recent products such 
as the Intel Xeon Phi have totally separate memory. I'm not aware 
of any general-computation-oriented products that don't have 
separate memory.

I'm also of the opinion that as long as people want to have 
devices that can scale in size, there will be modular devices. 
Because they're modular, there's some sort of a spacing between 
them and the machine, ex. PCIe (and, somewhat importantly, a 
physical distance between the added device and the CPU-stuff). 
Because of that, they're likely to have their own memory. 
Therefore, I'm personally not willing to bank on anything short 
of targeting the least common denominator here (non-uniform 
access memory) specifically because it looks like a necessity for 
scaling a physical collection of heterogeneous devices up in 
size, which in turn I *think* is a necessity for people trying to 
deal with growing data sets in the real world.

Annnnnnnnnnnndddddd because heterogeneous compute devices aren't 
*just* GPUs (ex. Intel Xeon Phi), I'd strongly suggest picking a 
more general name, like 'accelerators' or 'apu' (except AMD 
totally ran away with that acronym in marketing and I sort of 
hate them for it) or 
'<something-I-can't-think-of-because-words-are-hard>'.

That said, I'm no expert, so go ahead and rip 'mah opinions 
apart. :-D