7970 how many WUs most efficient? + While running seti artifacts in firefox


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Questions and Answers : GPU applications : 7970 how many WUs most efficient? + While running seti artifacts in firefox

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Dave
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Message 1408524 - Posted: 27 Aug 2013, 22:37:44 UTC
Last modified: 27 Aug 2013, 22:41:09 UTC

Hi,

I have two different questions.
First, how many WUs would you run on a 7970 + i3 2100? Currenty I'm running 5 WUs Seti@Home v7 7.03 opencl_ati_cat132. They take around 1300s.

GPU load is @ 99%, temperature @ 69°C.

Second question:
While running these 5 tasks, I get strange artifacts in firefox. They show up in the tab bar and vanish when I hover over them with the mouse.

Here's my app_config:

<app_config>
<app><name>setiathome_v7</name>
<max_concurrent>6</max_concurrent>
<gpu_versions>
<gpu_usage>0.167</gpu_usage>
<cpu_usage>0.667</cpu_usage>
</gpu_versions></app>
<app><name>astropulse_v6</name>
<max_concurrent>6</max_concurrent>
<gpu_versions><gpu_usage>0.167</gpu_usage>
<cpu_usage>0.667</cpu_usage>
</gpu_versions></app>-<app>
<name>setiathome_enhanced</name>
<max_concurrent>6</max_concurrent>
<gpu_versions>
<gpu_usage>0.167</gpu_usage>
<cpu_usage>0.667</cpu_usage>
</gpu_versions>
</app>
</app_config>


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Dave

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Message 1408563 - Posted: 28 Aug 2013, 0:27:17 UTC - in response to Message 1408524.
Last modified: 28 Aug 2013, 0:27:43 UTC

Second question:
While running these 5 tasks, I get strange artifacts in firefox. They show up in the tab bar and vanish when I hover over them with the mouse.

Yes, that's a side effect of having an AMD HD7xxx GPU. This is a problem with the GPU manufacturer severely underclocking the 2D memory. You can try to overclock the 2D memory to see if it goes away.
I've tried it, but even with a 2D GPU clock of 600MHz and memory speed of 1050MHz I still see the artifacts. You'll only see them in 2D environments, not in 3D (games and such).

There's also a real possibility that (part of) your screen starts jittering when the GPU reaches a certain temperature. Mine shows vibrations at the top of the screen at 58.5C to 59C.

Sapphire HD7870 GHz Edition, 2 GB.
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Message 1408714 - Posted: 28 Aug 2013, 6:34:11 UTC
Last modified: 28 Aug 2013, 6:35:43 UTC

Thanks for your answer.
It didn't take me long to find this bugreport on firefox:
https://bugzilla.mozilla.org/show_bug.cgi?id=837489

So apparently I'm not the only one and it has nothing to do with SETI.
Setting the gfx.direct2d.disabled to true eliminated the artifacts.

Kinda ironic isn't it? Nvidia fanboys keep saying AMD driver's are bad and now I I tried an AMD gpu and what do I get? Driver problems lol

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Message 1408882 - Posted: 28 Aug 2013, 16:24:35 UTC - in response to Message 1408714.

Thanks for that, it was a worthy read. But it also shows that the real problem isn't in Mozilla or any of the other Gecko engine browsers (Chrome, Pale Moon), as Internet Explorer shows exactly the same artifacts.

It is to do with the speed that the Catalyst Control Center (CCC) sets for the 2D clock. As far as I know it happens when the 2D clock gets downclocked to save energy (goes to sleep). This happens especially during Direct3D and OpenGL sequences. OpenCL calculations make use of the OpenGL processors, so when you run with the OpenGL processors for a while, CCC determines that there's no need to keep the 2D clock at its normal cycles and thus it'll be turned down.

The lower clock is lower than what any GPU tweaking application shows.
E.g. on my HD7870, ASUS GPU Tweak states that my default lowest 2D clock is 600MHz, but it isn't. It's 100MHz.

You can check the value by opening Profiles.xml in C:\Users\{Your Username}\AppData\Local\ATI\ACE\ and looking for the first <Feature name="CoreClockTarget" entry. That's the default values of the 2D clock set by the CCC.

As far as I know, the only way to really get rid of the artifacts is to disable the CCC, then edit that file and change the lower values to higher ones, then reboot and have the computer run with the values you set. I haven't tried that yet, though. ;-)
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Message 1408933 - Posted: 28 Aug 2013, 18:30:44 UTC

btw 3 or Wu's at a time is pretty much all you can run at one time on the 7970
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Message 1409264 - Posted: 29 Aug 2013, 10:47:20 UTC
Last modified: 29 Aug 2013, 10:47:45 UTC

3 WUs simultaneously only? Read something about 8 WUs in the internet -_- Maybe I can find the thread again.

So settings then:
max concurrent 3
GPU usage .33
CPU usage 1 (Dual Core + HT)?

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Message 1409289 - Posted: 29 Aug 2013, 11:58:43 UTC - in response to Message 1409264.

It was 7-8 back on SETI@home Enhanced v6. Now it is about 2-3 with SETI@home v7 with auto-correlation which consumes many more CPU/GPU cycles than before. The trick is to use something like GPU-Z's sensor tab and keep adding workunits until the GPU usage hits 100%. You'll find that sweet spot around 3 workunits for a 7970 - I'd know because I have a 7970 as well.

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Message 1409301 - Posted: 29 Aug 2013, 12:38:22 UTC - in response to Message 1409289.

Ah, thanks. Now I got it.

What should I put in for CPU usage? I have an i3 2100.

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Message 1409312 - Posted: 29 Aug 2013, 13:20:48 UTC - in response to Message 1409301.

One real core should be adequate to feed a 7970. On my Core i7 3930K I've set my CPU usage to 75% of all available cores, which leaves two real cores and two virtual cores (HT) cores free.

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Message 1409476 - Posted: 29 Aug 2013, 19:05:19 UTC

start by freeing a core. if that doesn't help then free up a second core to help feed the beast
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Message 1409696 - Posted: 30 Aug 2013, 8:36:52 UTC
Last modified: 30 Aug 2013, 8:37:47 UTC

So...

In app_config: 1 = one core is reserved for each WU, right? (Which might be a bad solution since I only have a dual core + HT).

What does 0.5 mean then? Only "half a core" is reserved for each WU? And what would be best suitable for a dual core + HT in contrast to a real quad core?

By the way, task manager shows a very low cpu usage. Only at around 12% and reaching 2,4 GHz @ max.

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Message 1409882 - Posted: 30 Aug 2013, 18:26:25 UTC - in response to Message 1409696.

See http://boinc.berkeley.edu/wiki/Client_configuration#Application_configuration for what's what.
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Message 1410091 - Posted: 31 Aug 2013, 9:55:59 UTC

What I also don't quite understand is why some WUs take longer than other.
Been running 4 tasks now, 1 shows around 12 min to complete. The other one 35 min!

Thing is, they're both opencl_ati_cat132 WUs!

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Message 1410102 - Posted: 31 Aug 2013, 10:38:48 UTC - in response to Message 1410091.

Seti doesn't have all tasks of the same length. I don't think any project has tasks that are all exactly the same run time length. Anyway, how long a task takes here at Seti depends on what angle the telescope had when it recorded the data, known to insiders as AR or Angle Range.

Someone else will come along to explain it better, but I think that the higher the AR, the faster the task will be processed. You can see this mythical AR value when you open the task with Notepad (or any other plain text editor). Look for the value in the <true_angle_range></true_angle_range> brackets.
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Questions and Answers : GPU applications : 7970 how many WUs most efficient? + While running seti artifacts in firefox

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