randomshinichi
4th November 2010, 12:24
One day, I notice that my encodes aren't going at the 90-120fps rate they used to. Then I check Windows Task Manager, and WTF, x264_64.exe only uses 3 threads! BTW I'm running a Phenom II X6 1055T at 3.8GHz, it's been stable for some time now, so the OC can't be the problem.
So I thought maybe the x264 builds were the problem. After all, they're at build 1649, and the latest is 1745 or something. But none of the vanilla builds I found online would work with vfw4x264.exe, which I assume is a wrapper.
I tried adding --threads=7, making sure Threads is set to 0 in the GUI (BTW increasing the number there doesn't change the commandline in the settings pane), but it seems it's just ignored. Also, sometimes x264_64 changes its number of threads, sometimes 5 threads, maybe 4, and it stayed at 3 threads for a long time, using just 40% of my CPU.
OK that's strange, when I checked "Slow first pass", it's finally using 6 threads sometimes, and as a result it's proceeding at the same speed as without "slow first pass". My settings are as follows:
program --level 4.1 --pass 2 --bitrate 650 --stats ".stats" --slow-firstpass --b-pyramid strict --ref 4 --me umh --output "output" "input"
Maybe the first pass just doesn't require much CPU? But that means the bottleneck is in the input, i.e. vfw4x264, which should then speed up, but itself isn't using all my CPU (only 30%). My hard drive isn't being hammered either. So what's the problem?
So I thought maybe the x264 builds were the problem. After all, they're at build 1649, and the latest is 1745 or something. But none of the vanilla builds I found online would work with vfw4x264.exe, which I assume is a wrapper.
I tried adding --threads=7, making sure Threads is set to 0 in the GUI (BTW increasing the number there doesn't change the commandline in the settings pane), but it seems it's just ignored. Also, sometimes x264_64 changes its number of threads, sometimes 5 threads, maybe 4, and it stayed at 3 threads for a long time, using just 40% of my CPU.
OK that's strange, when I checked "Slow first pass", it's finally using 6 threads sometimes, and as a result it's proceeding at the same speed as without "slow first pass". My settings are as follows:
program --level 4.1 --pass 2 --bitrate 650 --stats ".stats" --slow-firstpass --b-pyramid strict --ref 4 --me umh --output "output" "input"
Maybe the first pass just doesn't require much CPU? But that means the bottleneck is in the input, i.e. vfw4x264, which should then speed up, but itself isn't using all my CPU (only 30%). My hard drive isn't being hammered either. So what's the problem?