Hans, On Sunday 26 November 2006 14:48, Hans du Plooy wrote: > Hi guys, > > Just wondering. If I set a single process to have a nice value of > -1, and the process does not use 100% CPU, why does it make the whole > machine sluggish? > > I'm busy transferring video from VCR to my notebook. Mencoder is > using between 60 and 80% CPU at any time, so performance is not an > issue. But to avoid framedropping when I open or close something > while working in the meantime, or to avoid disaster when updatedb > kicks in, I set mencoder to be nice -1. Even though mencoder still > only uses 60-80% CPU, everthing else is now sluggish - even the mouse > movements are slow and jerky.
There's more to what happens in a computer than CPU usage. I/O matters, too, as do interrupts (the mouse, like all I/O devices, being interrupt-driven). Probably it's I/O load that's slowing your system even when mencoder doesn't need all or even most of the CPU. In fact, I/O limits may be slowing mencoder, too. I'm not sure it will help, but you might want to familiarize yourself with "ionice." As the name suggests, it's the I/O counterpart to "nice," which addresses only CPU consumption. How many independent disk drives do you have? What bus do they use (i.e., SCSI, IDE or SATA)? What spindle RPMs do they use? Have you configured optimal DMA for all your high-throughput devices (disks and your video interface hardware, at the least)? > Thanks > Hans Randall Schulz -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
