RAID stripe size increases encoding speed?

[eagleone]

I frameserve from Vdub to CCE. I have noted a significant increase in CCE encoding speed by changing the stripe size from 16 to 64k. Any other similar experiments?

How can I benchmark it better to find the optimum stripe size? I can not use a general benchmark for this, I have I/O meter and Win2k's performance counters.

[dmonty]

To get the most from your RAID setup you will need to make some compromises. What is the main purpose for your PC? If you use it mostly for video then set your stripes to the largest size. This would work better for you since video requires heavy sequential read/writes. A larger stripe size allows your PC to retrieve more data in a single pass. For example: In theory a 64K strip would return 4x more data than a 16K stripe during a single pass. Please note that while this is great for video or large files its slow for most apps. For office apps and games you might want to stick with a 16k or 32k stripe.

While I can't recommend any benchmarking tools here are some RAID tips you can try:

I recommend that you use identical hard drives for the greatest increase in performance. While it is not necessary, your disk array capacity will be equal to the number of drives times the smallest drive. Also speed of the array will depend on the speed of the slowest hard drive. So if you built your array from spare parts you might want to upgrade.

If you have the room you might want to add another HD to serve as a 'dump' for your movies. This should increase speed even further because I/O does not need to be performed by the same drive or array. Example: a video source on drive 'c:' that is being sequentially read and written to drive 'd:'

Oh... One more thing. Video encoding is almost completely dependent on CPU speed and available memory. If the size of your stripes is having this much impact on your encoding speed then I suspect that you’re caching video in your HDD’s swapfile. If this is correct then you would benefit from more memory.

Hope this helps,

D