CPU at 16%?

Ron Windeyer · February 1st, 2012, 02:47 AM

Addendum to previous note: it gets more confusing. The mp4 file prepared with GPU assistance, which took longer, is 438 Mb and has a nominal data rate of 25254 kbps (Ok, it varies..). The file prepared without GPU assistance is 382 Mb and has a nominal data rate of 21969 kbps. And I didn't change anything I swear!

To the naked eye they look the same...

HUH??

Gints Klimanis · February 1st, 2012, 04:01 PM

I now have Vegas11. I don't notice a slow down, but I don't notice a speed up with GPU for a basic render of HD footage. I will experiment with over clocking the nVidia 560Ti. There are other factors such as disk write operations and on-CPU cache as well as main memory bandwidth. Bring up the task manager and check out the options to monitor memory and disk operations.

A graph of CPU usage utilization is not an accurate measure of the efficiency of a process, and we should not be distracted by comparing the graphs. If the threads running on each core are stuck waiting for the results of another core or to access the off-chip cache or main memory, then the core will not be used at its full-capacity and its bar graph will be short. If a thread is running highly repetitive math operations that does not need a river of data in to produce a river of data, then the cores will have a large bar graph.

Gints Klimanis · February 1st, 2012, 04:09 PM

Quote:

Originally Posted by Ron Windeyer

The mp4 file prepared with GPU assistance, which took longer, is 438 Mb and has a nominal data rate of 25254 kbps (Ok, it varies..). The file prepared without GPU assistance is 382 Mb and has a nominal data rate of 21969 kbps.

We shouldn't be surprised that different MP4 encoders are used for GPU and CPU, but it would be good to what is different. Which model of GPU? A good feature for the future would be for Sony software to figure out if GPU rendering is better or worse and adjust automatically.

Stefanos Lampridis · March 16th, 2012, 03:26 AM

First of all, great thread.

I had the same question for my machine. cpu was somewhere 15-25% while rendering.

I now work on a project that has some magic bullet effects and sone new blue and some color corecting from Sony's own plugins.

The magic Bullet ones are SLOW. and not using all threads of the cpu

New Blue, cope better

Sony's is way faster, but do only the basic stuff, unfortunately.

Anyway, if i disable the GPU from the magic bullet preferences, cpu DOES engage at high percentages, but does not makes rendering any faster.

Machine: i7 960 (OC@3.6) 24GB ram @ 1600, NO raid, NO ssd's just different hdd for everything.

February 1st, 2012, 02:47 AM	#16
Ron Windeyer Regular Crew Join Date: Jul 2011 Location: Perth West Australia Posts: 27	Re: CPU at 16%? Addendum to previous note: it gets more confusing. The mp4 file prepared with GPU assistance, which took longer, is 438 Mb and has a nominal data rate of 25254 kbps (Ok, it varies..). The file prepared without GPU assistance is 382 Mb and has a nominal data rate of 21969 kbps. And I didn't change anything I swear! To the naked eye they look the same... HUH??

February 1st, 2012, 04:01 PM	#17
Gints Klimanis Inner Circle Join Date: Jun 2003 Location: San Jose, CA Posts: 2,222	Re: CPU at 16%? I now have Vegas11. I don't notice a slow down, but I don't notice a speed up with GPU for a basic render of HD footage. I will experiment with over clocking the nVidia 560Ti. There are other factors such as disk write operations and on-CPU cache as well as main memory bandwidth. Bring up the task manager and check out the options to monitor memory and disk operations. A graph of CPU usage utilization is not an accurate measure of the efficiency of a process, and we should not be distracted by comparing the graphs. If the threads running on each core are stuck waiting for the results of another core or to access the off-chip cache or main memory, then the core will not be used at its full-capacity and its bar graph will be short. If a thread is running highly repetitive math operations that does not need a river of data in to produce a river of data, then the cores will have a large bar graph.

March 16th, 2012, 03:26 AM	#19
Stefanos Lampridis Regular Crew Join Date: Jul 2009 Location: Piraeus Greece Posts: 28	Re: CPU at 16%? First of all, great thread. I had the same question for my machine. cpu was somewhere 15-25% while rendering. I now work on a project that has some magic bullet effects and sone new blue and some color corecting from Sony's own plugins. The magic Bullet ones are SLOW. and not using all threads of the cpu New Blue, cope better Sony's is way faster, but do only the basic stuff, unfortunately. Anyway, if i disable the GPU from the magic bullet preferences, cpu DOES engage at high percentages, but does not makes rendering any faster. Machine: i7 960 (OC@3.6) 24GB ram @ 1600, NO raid, NO ssd's just different hdd for everything.