OpenCL

[mutluit]

Hello,

in my laptop there are 2 GPUs (one internal as APU, and the other as standalone on MoBo). Where at AMD can I download technical documentations for these GPUs? I mean full documentation, not a simple broschure or so. I need the data for OpenCL programming, ie. data like #shaders, #pipelines, #ComputeUnits etc.

$ lspci
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Richland [Radeon HD 8650G]
01:00.0 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Sun PRO [Radeon HD 8570A/8570M]

Thx.

[mutluit]

Related question:

The CodeXL web site says "Note: Support for pre-GCN GPUs has been discontinued in the latest releases and is available only in the legacy AMD CodeXL 1.9 release."

So, do the above said GPUs use GCN, or are they pre-GCN?

[dipak]

HD 8570M belongs to 1st generation GCN family, whereas HD 8650G is a pre-GCN product.

You can find the list of legacy graphics products here: Legacy Graphics Products 

Thanks.

[mutluit]

Thank you.

Where can I find further information about the other features of these GPUs, like #shaders, cache, memory, pipelines, #CUs etc.? Ie. programmer documentation for these GPUs.

[dipak]

I usually refer this below wiki page to quickly find information about any AMD GPU. It's a really useful reference.

List of AMD graphics processing units - Wikipedia 

Another good way to get OpenCL specific information is via "clinfo" utility. It comes with the driver. It prints detailed information about all the detected GPUs.

Thanks.

[mutluit]

From these tables at wikipedia I collected the following data for my 2nd GPU:

GPU: Mobile Model: "Radeon HD 8570M / 8650M (Sun Pro)", GCN 1st gen (28 nm), Cfg 384:24:8

Cfg means: Unified Shaders : Texture Mapping Units : Render Output Units

And clinfo says:
AddressBits: 64
Compute Units: 5

It seems that normally 64 shaders make up 1 Compute Unit.

I wonder why this is not the case with the above GPU: it has only 5 CUs. Shouldn't that rather be 384/64 = 6 ?

[dipak]

I'm not sure why this difference is. From the wiki data, it looks like the gpu has 6 CUs. However, if the clinfo reports 5CUs, then it should have 5*64 = 320 PEs. Can you please run some other utilities like GPU-Z to verify the gpu information?

[mutluit]

Hi dipak, appreciate much your helpful input.
Unfortunately GPU-Z seems to be a Windows-Only utility. I don't have any Windows; I'm using Linux.
Do you, or anybody else, know a similar tool for Linux (other than clinfo)?

Thx

[dipak]

By the way, this official page says that HD 8570M has 5CUs - https://www.amd.com/en/product/6941 

For more official specs, please see: https://www.amd.com/en/products/specifications 

Thanks