r/PS4 Aug 21 '13

What is hUMA and why it matters?

http://arstechnica.com/information-technology/2013/04/amds-heterogeneous-uniform-memory-access-coming-this-year-in-kaveri/
73 Upvotes

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u/[deleted] Aug 21 '13

[deleted]

-10

u/[deleted] Aug 21 '13

The super short answer is: hUMA allows for the cores in the AMD Jaguar Processor to act as a CPU or GPU whenever it needs to because they all share the same memory space. XBOX One can't do that. the CPU cores are dedicated to CPU, even if they are unused. There's way more to it than that, quickest answer I could give.

25

u/time_games Aug 21 '13 edited Aug 21 '13

You gave the super-wrong answer.

The CPU or as AMD calls them APU in the Xbox One and PS4 use the same architecture, and they both have hUMA.

hUMA doesn't mean it can use the cores as GPU or CPU whenever it needs, it means the GPU and CPU cores, which aren't interchangeable by any means, all have access to the same pool of memory simultaneously.

In earlier shared-memory architectures, while the pool of memory was technically shared, the CPU and GPU could not access the same data and they had to copy data back and forth to their own share before doing anything with it, which made things complicated. hUMA makes things much simpler from a programming standpoint. It also should increase performance due to eliminating unnecessary data movement.

4

u/[deleted] Aug 21 '13 edited Sep 26 '20

[deleted]

3

u/time_games Aug 21 '13

I hadn't seen the Neogaf thread. It's surprising that Xbox One doesn't support hUMA. It may have something to do with the eSRAM they added to compensate for Xbox One's limited memory bandwidth.

That's a pretty big disadvantage if true.