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Rendering on Quad core processor
Hopefully a simple answer to this…
I’m sure that when i normally render 100% .AVI stuff it uses 100% CPU but i’ve just noticed that my both my pc’s (Quad core) are currently rendering their respective projects at around 30% CPU. Both the projects are very similar in that they include a couple of different media types (.avi & .PNG) and involve quite a lot of .PNG graphic layers
Anyone know why this is? Any way of increasing the CPU % for these jobs?
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8 Replies
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Can i just clarify: I’m rendering the projects to MPG2 for DVD. I normally work with just .AVI material on the timeline plus a few Pro titler events – this is when i see 100%. The two projects that i’m currently working on consist of about additional tracks of .png files, some continuous, some just short events, as well as the .avi video.
Cheers
Chris.
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Sorry. Also, i’m using Pro 8.0c.
Just tried rendering another project, one of the simpler ones that i mention previously, and the CPU shoots straight up to 100% as normal. Must be something to do with the .png files that i’ve included.
Any ideas?
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If you have added any FX’s that are not multi-threaded, Vegas will have no choice but to use a single thread which will only use 1 CPU. What FX’s do you have on this project that the other projects don’t have?
~jr
http://www.johnrofrano.com
http://www.vasst.com -
Thanks for the pointer.
The only external effect that i’m using is Magic Bullet Looks 1, and that’s only occasionally on the timeline. The rest are effects/pans/crops etc that are all from within Vegas.
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Right, i’ve found the culprit and it’s doesn’t seem to make sense.
My Computer renders at 100% of CPU when i render a single project from it’s timeline. However, when i start using nested files it renders at around 30-38% of the CPU.
Why does it appear that Vegas is giving me less power just when i need it??
At the moment my 10 min project is taking around 3 hours to render. It is quite a complex project but still, 3 hours!!!. where’s the rest of the CPU gone!!
Thanks
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I ran into this sort of problem years back, on a wedding video, in Cineform, with many dozens of JPEG files in 6MPixel and 8MPixel sizes.
Without really thinking about it, I had all assets on one hard drive, and I was rendering back to that hardware. Being an audio guy, I should have know immediately that this could be a bad idea, but it took me awhile to get the clue.
Hard drives are we know them have two primary performance metrics. One is their straight-streaming performance.. maybe 25-50MB/s or more for a good drive these days. If you run a simple HDD benchmark, that’s the number you get.
The other is the seek time, usually quoted as an average … it might take 5ms (milliseconds) to seek from track to track. For large files, you of course have more seeking… since the distance between files is more. So large PNGs, video files, etc. all on the same drive… could be bad. And where are you writing the render… not back to the same drive, I hope?
Anyway, essentially, as you add tracks, the performance of the drive moves away from that streaming peak, and toward the seek time. And not surprisingly, if you have more cores, the effect is all that much worse, since you’re hoping to render multiple segments of video at the same time.
I’m not sure just how smart Vegas gets about this if you have more memory (hopefully, a 64-bit version of Vegas and at least 4-8GB of memory)… when there’s more memory, individual buffers can be larger, minimizing the number of seeks per second. But I don’t know what Vegas does in this respect.
In any case, try directing your output to one drive, move the video or PNG to another if possible, and see if that helps. Don’t worry if the C: drive is involved; if you actually need page swapping during a render, you’re already beaten. Another trick to try — cut the render down to two or three cores, and see if the CPU utilization actually goes up.
-Dave
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That’s an interesting observation about nested projects. I have not noticed this behavior but I’ll have to keep an eye out for it in the future.
~jr
http://www.johnrofrano.com
http://www.vasst.com -
Thanks for your responses.
What you have said, Dave, makes perfect sense. I AM rendering to different drive to that of the source files but the source files are spread not only across one drive, in different locations, but also over to another networked computer via a 1GB connection. The main drive that most of the source files are on is connected to the PC by USB as i haven’t got around to getting the correct E-SATA card to utilise the RAID facility. I’d imagine that all of this leads to a bit of a bottleneck situation, which is what i’m seeing.
Just out of interest, do you think that having some of the source files located in places with quite long directory addresses also causes a problem? We’re only talking about 100 character long or so…
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