Since I quit using multithreading avisynth, I decided to run 4 separate encodings each with AA to multithread. Here's my problem. My CPU is not running at 100% like it should. Sometimes each encoding runs at 25% (1/4 of my quad core), sometimes it runs at 0-5%. Therefore my CPU is never running at 100%, more like 60%. I'm running 4 of this on a lossless source, 3 of them use the one on my external hard drive (through USB 2.0), and 1 use a copy on my main hard drive. Each encoding has its own filters (yes, I made 4 copies of the same filter) Here are the only problems I can think of: 1) Some encodings are using virtual RAM, and my hard drive can't move fast enough. But I don't see my hard drive light being steady. 2) My external hard drive's USB 2.0 is the bottleneck (running at 30MB/s). My external's light is blinking good, but I don't know how it can be a bottleneck. Yes, the lossless source is 100Mbps, but each encoding is running from 0.01-0.05fps, a 30MB/s connection isn't good enough for 3 encodes? Anybody got a clue as to what is preventing my computer from using 100% of my CPU?

You didn't tell use what you are using to encode. Xvid or X264?

And, what format is the lossless source in? Uncompressed RGB, x264-lossless, Huffyuv, FFV1, Snow, Lagarith, CorePNG, WARP, ... ?

x264 lossless

Yes, your external HDD and the USB connection are the bottlenecks. Even with a local harddisk (XviD TGEDIT preset ~25Mbps), I notice some slowdown with 4 simultaneous encodes. Do make sure that you have enough memory though. Run taskmgr to verify your memory load. Also, you may want to ensure that each encode is using 1 thread only. The Windows kernel is not particularly efficient for multiple multi-thread CPU-intensive programs. From my experience, 4 single-threaded encodes run faster than 4 quad-threaded encodes in my Q6600 machine.

I confirmed hard drive bottleneck as well, but why would 4 encodings running at 0.02fps cause a hard drive bottleneck, even if the source is x264 lossless and I'm encoding to x264 lossless?

you have 3 simultaneous reads of 100 mbps going on your external. and since it appears you're also writing back to it, that's 3 simultaneous writes. you have 6 simultaneous I/O operations working on your external. no HDD can realistically handle all the seeking and transferring such large amounts of data in this fashion well.

I would suggest to you to just use the MT avisynth. There should be nothing wrong with MT("AA()",4,8) (4 threads, 8 overlap, insert your appropriate AA filter as well)

@kemuri 9 It would still be a problem when the hard drive is supposed to read 1 frame per minute for each encode? @the guru There would be something wrong whwn you are on a 32 bit OS. I tried MT, but it would only use 2 cores + x264 or 3 cores in virtualdub before running out of memory.

I have a Q6600 + 3GB RAM on a 32bit Vista. The memory problem is because of multithreading, because all I did was write setmtmode (2,x) before everything else. I tried (2,0), ran out of memory. (2,3), barely allowed, no encoding. (2,2), can encode, but speed improvement not as great as running 2 separate encodings.