Hi,

I'm new to Kdenlive but I used to use iMovie. The reason why I switched was that doing any work with video on my iMac took too long. I had a Linux machine I built a year ago that I'd originally intended as a Hackintosh but I built another machine for that instead. The box I'm using for Kdenlive is running Ubuntu 10.04 Beta and has 8GB of DDR2.

When I first tried Kdenlive last week I made a PAL DVD with 80 minutes of footage of rugby match taken in HD with a Samsung VP-HMX20C. It produces MPEG-4 files. I didn't do anything special, I just added all the clips to the timeline and then got it to render to DVD 4:3. It took about 2 hours 35 minutes to render. Both cores were at 100% utilisation.

That was too slow for me (way faster than the mac but I'm an impatient sort of person). So I decided to change the processor in the box. The original one was a core 2 Duo 8200 and I replaced it with a Core 2 Quad 9400.

Doing the same thing today, the render has taken 4 and a half hours. I've looked at system monitor and all four cores are being used, not always at 100% but always with one or two between 95 and 100%, one of the others typically at 75% or higher and the last always at least 55%.

Can anyone suggest why this is happening and if there's anything I can do to speed this up? I'd like to get the render times down below an hour as we use these dvds for analysis purposes and the sooner we can get them out to coaches and players the better.

One other thing to mention is that this Ubuntu is the 32-bit version. After Thursday when 10.04 goes production I'll change to the 64-bit version but the two tests were both on 32-bit so it shouldn't invalidate the results unless the extra speed that should be provided by more cores is limited because there isn't enough memory per core now?

Thanks for your help.

I'm not sure but 64-bit should work better since quad core processors work better with 64-bit. I'm surprised all four cores showed up in system monitor in 32-bit.

Are you using the Kdenlive builder wizard, packages, or manually compiling?
If you are not using the builder wizard and have not modified the render profile or set the decoding threads on the clips' advanced properties, then it should only use roughly 2.5 cores - does for me on my 8 virtual core i7.