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CPU not fully loaded when rendering?
I have built a new machine specifically for video editing and other CPU intensive tasks to keep things moving fast. I usually render HD YouTube videos and HD home movies, nothing professional or anything so I bought Sony Vegas Movie Studio HD 11.0 (not Platinum or Pro, just the basic). The specs of my new computer are:
Mobo: GIGABYTE GA-Z77X-D3H
CPU: Intel Core i7 3770k (default, not overclocked)
Cooler: Coolermaster Hyper 212 EVO (works a treat, i7 sits at ~25degC idle and only works up 50-60degC when rendering)
Memory: 16GB (4x4GB) Corsair Vengeance DDR3 1600MHz
Disk 1: OS/Programs disk OCZ Vertex 4 128GB SSD SATAIII
Disk 2: Raw video/project media/rendered video drive WD Black 1TB SATAIII
Video card: NONE – using the i7s integrated Intel HD Graphics 4000With all this raw horsepower, Vegas only utilises 70% of the CPUs power. I’ll admit whilst I am quite pleased that unlike most other programs Vegas is using all 8 threads of the processor rather than just the 4 cores it still doesn’t use them 100%.
I’m using the Windows Media Video V11 render profiles (due to the edition, I can’t alter specifics) and even tried Sony AVC to compare with (also only uses 70%) but I like the WMV profiles better.
Basically, my question is why is it like this and can I get it to utilise 100%? My guesses are:
– All threads are used, so being 2 threads to a core means the core is actually fully loaded
– My “basic” copy of Vegas is restricted to make it slower and try to get you to upgrade
– The memory isn’t running at 1600MHz all the time and the access times are a bottleneck (seems to change, sometimes at 1066 then 1333)
– Disk r/w times are the bottleneck (doubt it, but possible)
– No graphics card with features like CUDA to help out encoding added (I don’t think the basic Vegas edition can use this anyway)Any ideas? Thanks!
If you need more info, just ask.
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1 Reply
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First of all, assuming that the task manager is counting both threads per CPU in its formulation for full CPU percentage, you’ll probably never get to 100%, at least as if it’s being calculated the same way you would for a real 8-core machine. The idea of the hyperthreading system is to fill in pipeline delays (eg, read/writes to/from cache or memory) by swapping the CPU register set to the alternate thread. That’s going to utilize the CPU’s basic hardware better than a straight four-core chip, usually (basically, as long as you don’t start thrashing on-chip cache), but it’s still not going to match that of an 8-core. So that may be your first bottleneck.
Disc speed matters more, obviously, as your CPU increases in performance. You’re probably fine with a single file in and out to the same drive, but in general, writing back to the primary media source drive will case increased seeking — and thus, very decreased HDD performance. You can test this by writing the output to a different drive… the C: drive is fine (you have no seek issues with an SSD, though of course, you’d like to minimize writing to them, they don’t have as many write cycles as a magnetic HDD), or any external drive. At least, as long as you’re not rendering any crazy formats, something MPEG-ish is good.
And I hope you didn’t mean actual RAW, eg, uncompressed video when you say “Disk 2: Raw video”… Raw HD video is going to make most any single HDD a bottleneck.
-Dave
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