# CPU at <40% during video rendering - where is the bottleneck?



## seanspotatobiz (Apr 22, 2010)

If my CPU is less than 40% occupied during video rendering, what can I investigate in my system in order to speed up the process? Could it be my HDDs or my memory?

System drive: Maxtor Diamondmax 22 500GB SATA-II 32MB
Video files: 2 x Maxtor DiamondMax 10 6B160M0 160GB SATA-150 8MB = RAID 1


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## Kornowski (Apr 22, 2010)

Perhaps the video doesn't need more than 40% of your CPU to render. Is it HD? What program are you using?


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## seanspotatobiz (Apr 22, 2010)

Kornowski said:


> Perhaps the video doesn't need more than 40% of your CPU to render. Is it HD? What program are you using?



Hey. The video is HD.

With VirtualDub 1.9.9, the CPU is at less than 40% and with Sony Vegas 9.0c, the CPU is at less than 60%.

I want to know what component of my system is limiting the speed of rendering a video at the end of editing. Depending on the situation, it takes a minute to half an hour (potentially more) to render edited footage to .mp4. What upgrade would enable rendering in less than the current time?


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## Kornowski (Apr 22, 2010)

What format is the video in? I just downloaded VirtualDub and it won't import .mov files, which demand the most processing power. 

When I render HD footage out of Adobe Premiere all my cores are @ 100%. Is it 720 or 1080 you're using?


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## Geoff (Apr 22, 2010)

What are you using to determine your CPU usage?  Chances are the program can't utilize more then 2 cores effectively, and since you have a quad core processor, only half of that can be fully utilized by that program giving you <50% usage.


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## seanspotatobiz (Apr 22, 2010)

Kornowski said:


> What format is the video in? I just downloaded VirtualDub and it won't import .mov files, which demand the most processing power.
> 
> When I render HD footage out of Adobe Premiere all my cores are @ 100%. Is it 720 or 1080 you're using?



The video format is .avi (which made the file humungous (1.2 GB for 10 seconds!) but I wanted it to be lossless for the stablisation filter which I wanted to apply in VirtualDub before importing it back into Vegas. I couldn't open the files which my camcorder produces directly (.m2ts) in VirtualDub; they had to go through Vegas first.

The resolution is 1080 lines.



			
				[-0MEGA-];1459217 said:
			
		

> What are you using to determine your CPU usage?  Chances are the program can't utilize more then 2 cores effectively, and since you have a quad core processor, only half of that can be fully utilized by that program giving you <50% usage.



I'm using Windows Task Manager which I think reports CPU usage for each core individually and shows roughly equal usage across all four cores.


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## linkin (Apr 23, 2010)

I doubt you have a bottleneck, everything appears to be normal.


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## seanspotatobiz (Apr 23, 2010)

linkin said:


> I doubt you have a bottleneck, everything appears to be normal.



I don't understand... are you saying that I have achieved the fastest possible rendering times that the laws of physics will allow? I know that you're not! so what's holding me back?


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## linkin (Apr 23, 2010)

I'd actually say that the software is not taking full advantage of the hardware. therefore, the software you are using is a bottleneck.

It is a sad fact that some software is faster than other software. Try using a different program or updating the one you have.


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## Kornowski (Apr 23, 2010)

See if you can give Adobe Premiere a go. When I use it I use all four cores at 100%.


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## OvenMaster (Apr 25, 2010)

linkin said:


> I'd actually say that the software is not taking full advantage of the hardware. therefore, the software you are using is a bottleneck.
> 
> It is a sad fact that some software is faster than other software. Try using a different program or updating the one you have.



This. I've done video rendering with Nero and with DVDFlick. Nero used ±60% of my dual-core CPU capabilities, but the audio lost sync with video. DVDFlick uses only about 45-50% of my CPU's power, but the results are in sync, and the video looks better, too.


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