Script Speed Variations

[MysteryX]

When I run an AviSynth script with AVSMeter (or encode it), sometimes it performs faster than other times. I'll get a run at 12fps, then the next run will be 11fps or even 10fps. It runs stable, but not always at the same frame rate.

What can causes such variation? The only thing I could think of is that it's using various parts of memory, some of which perform slower than other, but I don't think that makes sense.

Any idea?

[junh1024]

One Possible cause: https://www.google.co.nz/search?q=ASLR

[Groucho2004]

I'd check first for background processes/programs that might eat your CPU cycles secretly like AV software.

[MysteryX]

One Possible cause: https://www.google.co.nz/search?q=ASLR
I wouldn't be surprised if it was related to that; but how would that hurt performance when memory is allocated at certain places?

I have a Quad-core i7, it's not using all of it especially since the bottleneck is the memory transfer between the CPU and GPU.

[MysteryX]

x264-10bit.exe has a higher cost on performance than I expected.

My script runs at 10.3 fps in AvsMeter.

When sending through x264-10bit on "veryslow", it goes at 3fps. CPU usage stays between 75-79%. 8-bit encoding is considerably faster. Is it normal that this is making such a poor use of the CPU?