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Comment by pandaman | Hacker News Reader

Wow, memory access on NVidia is pretty bad. AMD has a separate unit that coalesces memory requests and goes through cache so if you do strided loads, for example, the next load will likely be reading data cached by the previous one and it does not matter how many lanes are active. AMD has 64-wide "wraps" btw and it does not seem superior to NV in computation on the same number of ALUs.

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I did my grad research on disease transmission simulations on GPUs, so this is super interesting to me. Could you please hit me with some papers or presentations?

The NVIDIA memory model also goes through L1 cache - but that's obviously not very big on a GPU processor (also true on AMD IIRC). Like <128 bytes per thread. It's great if your threads hit it coalesced, otherwise it's pretty meaningless.

I program AMD chips in game consoles so I use a different set of manuals but AMD has a lot of docs available to public at http://developer.amd.com/resources/documentation-articles/de...

At glance there is a lot of legacy stuff so I'd look at anything related to GCN, Sea Islands and Southern Islands. Evergreen, R600-800 etc are legacy VLIW ISA as far as I know.

There also fairly recent GCN3 ISA from 2015 available that shed light on their modern hardware architecture.

Well, sheds light on their Compute Unit architecture.

A friend of mine will be starting an epidemiology grad program this fall. Do you have some good basic pointers on the use of GPUs in the field? Also .. what is your opinion of the field in general?

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