"By default the app captures at 15fps, which should work for
most screencasts, but you can change it if the default doesn't work
for you.
"Also by default. RecordMyDesktop, encodes the video after it's
done capturing, which requires temporary storage space to store the
captured images. If you don't have the space, you can encode on the
fly, which requires a lot of processing power. Another option
designed to make RecordMyDesktop work on low-power boxes is the
ability to disable compression, which reduces overheads at the
expense of taking more disk space.
"Finally there's the option to enable quick subsampling, which
again helps ease the load on the processor - just use it as a
last-resort, as it might add blur to the videos. We used
RecordMyDesktop on a 1.4GHz Celeron laptop with 1GB RAM and a
dual-core Intel desktop, and it worked just as well on both
machines."