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cyseal
Adept III

Blender Cycles and Crimson 16.11.5

Testing with Crimson 16.11.5

I used this test file ps test.blend from :anchor: T50082 OpenCL issue and motion blur (AMD 7870 Pitcairn)

Render time with 16.11.3 is 15.28 seconds

Render time with 16.11.5 is 53.78 seconds.

ps test161005.png

Difference is 40 seconds ! That is very noticable performance drop.

Memory usage and memory peak are the same.

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18 Replies
dipak
Staff
Staff

Re: Blender Cycles and Crimson 16.10.4

H Sam,

Thanks for reporting. Actually a newer version (Crimson 16.11.5) is available now. Could you please check with that driver and share your observations?

Regards,

cyseal
Adept III

Re: Blender Cycles and Crimson 16.10.5

Additional testing with 16.11.5: in rendering process Blender stops and Windows is giving me the message something like

Driver stopped responding and has been recovered.

I haven't seen it clearly.

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dipak
Staff
Staff

Re: Blender Cycles and Crimson 16.11.5

Hi Sam,

Here is my finding (please check the timing) after running the attached blender file with Crimson 16.11.5 using the latest blender build (blender-2.78-05b181f-win64).

ps test.jpg

I ran it for multiple times with the "Motion Blur" option and observed more or less similar timing (i.e. within 15-17 seconds). Only for the first run, the timing was higher (close to 60 seconds) because of the kernel loading and building.

Did you refer the first run timing? Or Did I miss something during the testing? Just want to make sure that we are on same page.

P.S. Rendering without the motion blur option, I got the same observation as you mentioned here :anchor: T50082 OpenCL issue and motion blur (AMD 7870 Pitcairn)

Regards,

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cyseal
Adept III

Re: Blender Cycles and Crimson 16.11.5

Ah yes, when installing new version, kernel resets itself and takes more time to render in the first run. I forgot about that.

If you render without motion blur checked I got only 3.07 seconds to render but with almost black screen. User from the https://developer.blender.org/T50082

got 2.96 seconds without motion blur.

When I render more complex scene with sampling about 2000, Blender sometimes freezes and I got message about driver stoppped responding and had reset.

I used latest Blender version and 16.11.5.

ps test3.png

Is it possible to improve driver and OpenCl so that it loads the kernel faster and renders within 3 seconds particular scene?

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dipak
Staff
Staff

Re: Blender Cycles and Crimson 16.11.5

So, long kernel loading time is the issue here. I'll check with some other drivers and get back to you.

Btw, do you know how to force the blender to load the render kernels each time so that we could get the same effect as first run?

Regards,

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cyseal
Adept III

Re: Blender Cycles and Crimson 16.11.5

Yes, kernel loading and the black screen.

For example Fiji and Polaris (3xx and 4xx) cards do not have black screen issue. This was reported before.

Btw, do you know how to force the blender to load the render kernels each time so that we could get the same effect as first run?

Sorry, I don't know that.

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dipak
Staff
Staff

Re: Blender Cycles and Crimson 16.11.5

Hi Sam,

Here are observations regarding the two issues.

Issue 1: Long time difference

Actually the time difference is not there if you consider the kernel loading time for both the cases. Normally kernel loading (hence compiling) happens for first run and it saves those compiled kernels (CLBIN files in <user>\AppData\Roaming\Blender Foundation\Blender\<version>\cache\kernels). Next onward, it loads the compiled kernels if they exist (even though driver is different). So, the total render time is much less. I guess, your observed time difference is for that reason only. Please remove those CLBIN files before each run and check.

[As I checked for both the drivers with and without motion blur options, I didn't observe much difference. Please find the attached files for details.]

Issue 2: Not rendering properly without the motion blur option

My observation was same as yours. It's also working fine on Hawaii. So, as reported you earlier, the problem seems with SI cards only. I'll report this to concerned team.

Regards,

cyseal
Adept III

Re: Blender Cycles and Crimson 16.11.5

I saw the news for the AMD Radeon Software Crimson Relive Drivers Leaked, Massive Update

Will Cycles OpenCl fix for 7xxx cards be included ?

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dipak
Staff
Staff

Re: Blender Cycles and Crimson 16.11.5

Doesn't seem so. With Crimson ReLive 16.12.1, rendering without the motion blur on SI cards looks improved though some issue is still there.

Regards,

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