intel Iris 6200

[foldy]

The Windows intel opencl driver release notes say double precision cl_khr_fp64 is supported since (5th generation Intel® Core™ processors and above), this is Broadwell but not Haswell.
But on linux it seems there is not intel driver but an open source driver called Beignet which currently does NOT support double precision.
http://arrayfire.com/opencl-on-intel-hd ... -on-linux/

[bruce]

Thanks foldy. (I had already figured out the Hasswell error and edited my post.)

Now we need to determine if OpenCL2.0 support would be recognized and utilized by FAHBench (on Windows). I've asked that question of the experts but may not get an answer for a few days due to the holiday.

The energy calculations for larger proteins will need Double Precision although most of the other calculations only require SP. I don't expect FAH to support OpenCL 1.2 for GPUs but we might talk them into adding Intel support for 2.0. It would still be a significant development project but it helps to know if it is no longer a futile effort.

[Joe_H]

foldy, Intel has also released a driver package for linux that supports OpenCL 2.0 - OpenCL 2.0 Driver for Linux. The page says the following:

Intel has validated this package on CentOS 7.2 for the following 64-bit kernels.

Linux 4.7 kernel patched for OpenCL 2.0

What additional work is needed for other distributions someone with more Linux experience than me would have to comment.

[foldy]

OK, and this has cl_khr_fp64 double precision support also since (5th generation Intel® Core™ processors)

[bruce]

OK, the official answer is that FAHBench (and OpenMM) is smart enough to detect and use Double Precision if it's provided.

Is Intel OpenCL 2.0 something you have to install?

@foldy: What does FAHClient v7.4.15 report about that GPU? (It'll be "unsupported" but it still should report if OCL 2.0 is present.)

[foldy]

I found that for my 2nd gen intel cpu the gpu part intel driver does not support OpenCL.
So the OpenCL device I see in FahBench and FahClient is the CPU part only.
FahClient v7.4.15 says
Platform:2 Device:0 Bus:NA Slot:NA Compute:2.1 Driver:6.1

On Windows the intel OpenCl 2.0 is not a seperate package but included in the intel GPU drivers.
The other package "OpenCL™ Runtime for Intel® Core™ and Intel® Xeon® Processors" is only for CPU part and not needed for intel GPU part.

[bruce]

So maybe if you install the Intel GPU drivers (separate from the CPU drivers) FAH will find a GPU that's potentially supportable. The laptop I have today as a genuine Intel Atom (ugh) so I can't do any testing myself.

[foldy]

Intel GPU driver is installed but OpenCL not supported because of 2nd gen CPU, so Fah cannot find it.

[ComputerGenie]

Intel GPU driver is installed but OpenCL not supported because of 2nd gen CPU, so Fah cannot find it.

That was the same issue I had with the 530 for PC when I tried it; the 530 would bench, but not work for client.

[foldy]

What is your result running FahBench?
Can you post your FAH logfile to see if FAH lists you intel GPU?

[bruce]

Intel GPU driver is installed but OpenCL not supported because of 2nd gen CPU, so Fah cannot find it.

Right: The original question was:

intel Iris 6200 supports openCL 2.0
device ID:1622 (showed on intel HD Graphic control panel)
is there any plan to support it for calculations?

This whole topic limited to Iris 6200. You've demonstrated that we can forget about older CPUs.

If you do not have a CPU for which Intel supports OpenCL 2.0 FAH will certainly not support it. We MIGHT be able to talk FAH into supporting OpenCL 2.0 if there are enough of them but nobody is suggesting that might be true.

End of story.

[foldy]

By the way FahCores using OpenMM only need OpenCL 1.1 but the intel drivers also support that as OpenCL 2.0 is backward compatible.

[rwh202]

Intel GPU driver is installed but OpenCL not supported because of 2nd gen CPU, so Fah cannot find it.

Right: The original question was:

intel Iris 6200 supports openCL 2.0
device ID:1622 (showed on intel HD Graphic control panel)
is there any plan to support it for calculations?

This whole topic limited to Iris 6200. You've demonstrated that we can forget about older CPUs.

If you do not have a CPU for which Intel supports OpenCL 2.0 FAH will certainly not support it. We MIGHT be able to talk FAH into supporting OpenCL 2.0 if there are enough of them but nobody is suggesting that might be true.

End of story.

Anything post Sandy Bridge should have 1.2 support and post Haswell for 2.0. It's only the very old i7s without support. The vast majority of recent intel desktop and laptop processors should have the required OpenCL support.

In reality, only the higher spec GT3e and GT4e graphics will likely have enough performance to fold current GPU units and are performance comparable to the AMD APUs. These are branded as 'Iris' and 'Iris Pro' graphics. They aren't just shipping in highend laptops - all of our office NUCs have iris graphics and intel has orange of desktop processors featuring them.

However, given the volume of lower spec GT2 graphics, even they might we worthwhile targeting given the number of them, being present in just about every intel processor (often sat entirely idle in most intel gaming desktops with discrete GPUs). They will outperform the accompanying CPUs that still seem to be receiving some development attention.

[foldy]

Post Sandy Bridge (2nd gen) have OpenCL 1.2 support BUT only since Broadwell (5th gen) Intel OpenCL driver supports double precision, which I understand OpenMM needs.
As these iGPUs are mostly too slow to finish the normal GPU work units, they would need to create work units tailored for these iGPUs (maybe also including AMD iGPUs). That seems similar to the work units tailored for the CPUs. Maybe these small work units could also be used on slow dedicated GPUs?
They could fill the gap between slow CPUs and fast GPUs if that is feasible or useful from scientific aspect.

[ComputerGenie]

...
...We MIGHT be able to talk FAH into supporting OpenCL 2.0 if there are enough of them but nobody is suggesting that might be true.
End of story.

Errr...ummmm...no!

...
6h Gen Intel® Core™ i7 and Core™ i5 desktop processors support
graphics programmability features such as OpenCL 2.0 so programmers
can easily take advantage of the graphics compute capabilities...

...Imo, it would only seem logical that whatever the "actual" is, after 9+ total generations (over nearly 7 years between PC and notebook) it's obvious that the 21st Century includes this tech and as such is "worth the effort" to include the millions of units sold..."If you want the project to grow, the software has to include more hardware"...

A little bit back...

Intel GPU driver is installed but OpenCL not supported because of 2nd gen CPU, so Fah cannot find it.

That was the same issue I had with the 530 for PC when I tried it; the 530 would bench, but not work for client.

The 530 is 6th gen (Skylake), supports OpenCL, and doesn't work either.

...This whole topic limited to Iris 6200...

Do we really need a separate thread for every Intel processor that has the exact same issue?

...You've demonstrated that we can forget about older CPUs...

As I pointed out, we can forget about newer ones too (as the 6h Gen Intel® Core™ i7 launch date was Q3'15).