topic The EU is like a mini-cpu in OpenCL* for CPU

EU and Sampler

Biao_W_ — Fri, 21 Mar 2014 09:54:08 GMT

Hi,

I am doing GPGPU computing for video codec applications.

The algorithm adopted may use bi-linear filter which can take advantage of image sampler in OpenCL

However, I am not clear however it works using underlying hardware,

say if I use sampler, will it be possible that the sampler and EU execute at the same time?

Can anyone elaborate EU and sampler's difference/relationship?

Thanks

The EU is like a mini-cpu

Raghupathi_M_Intel — Mon, 24 Mar 2014 20:58:09 GMT

The EU is like a mini-cpu capable of performing a given operation on a given set of data. EUs can have multiple threads that help to keep the EU busy during a high latency operation. Some times, depending on what the program (shader/kernel) is doing, EUs require a texture read, for example. This is done by the sampling engine, which fetches the data (surface) from memory and filter based on filtering mode. While the EU is waiting for the sampler to return the data (called a stall), the EU can switch processing to another thread. When the data arrives, it can switch back to the original thread.

Hope this high level explanation is clear.

Thanks,
Raghu

Quote:Raghu Muthyalampalli

Biao_W_ — Wed, 26 Mar 2014 21:26:58 GMT

Raghu Muthyalampalli (Intel) wrote:

The EU is like a mini-cpu capable of performing a given operation on a given set of data. EUs can have multiple threads that help to keep the EU busy during a high latency operation. Some times, depending on what the program (shader/kernel) is doing, EUs require a texture read, for example. This is done by the sampling engine, which fetches the data (surface) from memory and filter based on filtering mode. While the EU is waiting for the sampler to return the data (called a stall), the EU can switch processing to another thread. When the data arrives, it can switch back to the original thread.

Hope this high level explanation is clear.

Thanks,
Raghu

Thanks for your explanation. I understand from the high level but would like to have a more detailed read.

Do you have something whitepaper introduce the sampling engine, Intel GPU in particular?