Odd finding about GPU Performance with Aero GUI Enabled/Disabled
26 Oct 2013 22:07:36 UTC
Topic 197234
(moderation:
I stumbled again onto a weird effect I discovered years ago (originally with Vista) but forgot about :
For my 24/7 crunching rig (Win 7 x64), I had the Aero GUI disabled (Visual Effects set to : optimize for maximum performance), thinking I may free a bit of performance.
As it just runs along by itself without me performing any manual task on it, I did not need a shiny looking desktop.
I'm not sure if it's the same with NVidia GPUs/Drivers, but with ATI disabling the Aero GUI actually decreases GPU performance, in my case on Einstein by approx. 5% (which is quite something).
[ Of 3 Cards in the System, both the HD7850 which is running the display is affected as well as the 2nd HD7850 which is just crunching. The 3rd, a HD7750 running only in a 4x PCIe2.0 slot does not show any difference. ]
I can only guess this occurs as the Video Drivers are naturally fully optimized for Aero, but not at all for the classic desktop (non-Aero) option.
Why that affects OpenCL performance in the same way actually surprised me.
...just thought I'd share that piece of info, in case there are other users who think disabling Windows Aero GUI might give them a performance edge.
To make sure, run both variants and compare at least a day worth of results for yourself in your configuration.
In case your OnBoard or On-CPU GPU is used for the Desktop and crunching (relatively low performance GPU w/ shared Memory), above statement may not apply - but it's still worth a test.
Odd finding about GPU Performance with Aero GUI Enabled/Disabled
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The performance hit is because the setting is optimizing for a system from a dozen years ago. The main hit you're taking is that Windows doesn't cache dialogs that are hidden behind something: As a result every time you restore a minimzed window or move a non-minimized one, you're forcing Windows to redraw part of the screen even though nothing has changed. This is only a good idea on systems which are extremely memory limited.
For a more detailed explanation see: http://blogs.msdn.com/b/oldnewthing/archive/2013/03/27/10405554.aspx
Thanks for the explanation..
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Thanks for the explanation.. but he's not doing any of this on his dedicated cruncher. I don't have anything else to offer, though.. :p
MrS
Scanning for our furry friends since Jan 2002
Thanks, that's the first
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Thanks, that's the first msndn reference I see about the issue.
Indeed though, the effect on GPUs not rendering the Desktop (2nd VGA cards) is still clouded.
I assume all (faster) cards are affected as all Display Devices in one system share the same display driver settings set by Windows for Aero/2D Rendering.
Maybe that component sets them all back a bit, causing the small performance penalty across the board (also notable in 3D Benchmarks, if I remember correctly)...