Scientific computing and parallel computing C++23/C++26

Nicholas Wilson iamthewilsonator at hotmail.com
Sat Jan 15 09:03:11 UTC 2022


On Saturday, 15 January 2022 at 08:01:15 UTC, Paulo Pinto wrote:
> On Saturday, 15 January 2022 at 00:29:20 UTC, Nicholas Wilson 
> wrote:
>> ....
>>
>> Definitely. Homogenous memory is interesting for the ability 
>> to make GPUs do the things GPUs are good at and leave the rest 
>> to the CPU without worrying about memory transfer across the 
>> PCI-e. Something which CUDA can't take advantage of on account 
>> of nvidia GPUs being only discrete. I've no idea how cacheing 
>> work in a system like that though.
>> ...
>
> How is this different from unified memory?
>
> https://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#um-unified-memory-programming-hd

there still a PCI-e in-between. Fundamentally the memory must 
exist in either the CPUs RAM or the GPUs (V)RAM, from what I 
understand unified memory allows the GPU to access the host RAM 
with the same pointer. This reduces the total memory consumed by 
the program, but to get to the GPU the data must still cross the 
PCI-e.



More information about the Digitalmars-d mailing list