View Full Version : 11.5 low CPU usage - how to optimize?

Thomas Helzle
02-14-2013, 09:47 AM
Hey, I could use a bit of advice here.

I'm currently rendering a lot of small previews (960x540) in Layout 11.5 64 Bit on Windows 8 Pro 64 Bit.
No Radiosity but 3 Dome-Lights and some Ambient Occlusion.
It's a GUI for a VSTi Audio Instrument, so it's basically a flat Panel and lots of instanced Knobs (Sorry, can't show it here) and an orthographic camera.

If I have Threads set to Automatic, my 2008 MacPro (running Windows) with Dual Quad Xeon 2.8 GHz, 14GB RAM, GeForce 8800GT reaches only about ~38% of CPU. I tried increasing the thread count (there are some renderers that actually are faster with more threads even if there are only 8 cores and no HT). CPU use increases and with 64 Threads I can get up to ~55% CPU, which still is pretty bad. The rendering takes about 2 Minutes.

Now I wonder: are there any ways to improve this?
In the past I was used to LightWave using pretty much 100% CPU.

I tried disabling the render preview, but that wasn't really significant.
Using LWSN would be a bit of a pain in this case.



02-14-2013, 10:21 AM
the amount of cpu usage varies depending on what the renderer is actually doing, so you may find in some cases that during AA passes it may not reach 100%. without being able to test the scene its hard to pin point where it is having problems. Some things don't multi thread as well as others

02-14-2013, 10:27 AM
Make sure "Enable image caching" is turned off.

Thomas Helzle
02-14-2013, 10:39 AM
Thanks Guys!

3DGFXStudios: You were Spot ON!!!!!!
I switched this on when exploring 11.5 and forgot about it.
Wow, quite some drastic result!

Now all is back to full CPU use as it should be, rendertime is down to 55 seconds - Cooooooool :-)

Thanks a ton!!!!