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Mac Pro 8 core + ATI Radeon HD 5870 very slow GPU after sleep

Hi,

I recently 'invested' in a HD 5870 for my Mac Pro 3,1 (OS X 10.7.2, Dual Quad Core Xeon 2.8 Ghz, 8 GB ram). It's a fantastic card and makes a big difference to FCP and gaming. HOWEVER. I've noticed a MAJOR issue, if you put the Mac Pro to sleep then after waking the GPU seems to function at one fifth normal speed. I've repeatedly proven this and have even managed to measure it using LuxMark (http://www.luxrender.net/wiki/LuxMark).

After a clean boot my LuxMark results are respectable:

Clean boot - 4299 (GPU only), 7130 (CPU+GPU)

However, after sleep / wake-up:

After sleep - 864 (GPU only)

And you can REALLY feel that slowdown, windows paint slowly, scrolling stutters. (Games are unplayable, only a reboot resolves).

Anyone else seen this issue / have any recommendations?

Mac Pro / MacBook Pro, Mac OS X (10.5.7)

Posted on Jan 25, 2012 5:27 PM

18 replies

philask Author

Level 1

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Mar 16, 2013 9:57 AM in response to Rupe

Sorry Rupe but while Apple appear to have made some changes the bug still exists, although not as noticeable as before.

Previously OpenCL performance was just 20% after sleep what it was before.

I've just tested again using LuxMark 2.0 and I'm seeing 60% after sleep compared to before.

So, not resolved.

Rupe

Level 1

10 points

Mar 16, 2013 10:26 AM in response to philask

I have been benching in games, not LuxMark 2.0. I prefer real world to any and all of these benchmark apps. I am using a UB version of Quake 3 1.3.2 with hires texture pack and the timedemo 1 test. I personally think that this game is the best benchmarking app ever made. It is what allowed me to find this bug in the first place and has consistently helped me to keep on top of any performance issues. My fps rates before and after sleep are maintained, prior to 10.8.3, fps rates would drop by 2/3rds.

Mar 16, 2013 10:58 AM in response to philask

I've also tested in Quake3 via the 5870 and it appears to be fixed on my end. I too dislike benchmark apps since they dont really seem to offer real world performance. Too many people spout off what their numbers are without actually confirming their tests numbers/configurations.

I ran LuxMark 2.0 in the following settings:

Scene: Room (Complex Benchmark)

Mode: OpenCL - GPUs ONLY (CPU IS NOT RELEVANT TO THE BUG!)

The numbers are the same on a FRESH boot and after sleep - only app open was Messages and Luxmark 2.0

I got 284-289 (4 Passes) 2 from Sleep and 2 from fresh boot as my result.

-dx

Mac Pro 8 core + ATI Radeon HD 5870 very slow GPU after sleep