When I run my Slack today I noticed that it booting process took double time to finish. Loading KDE - too. When I run XMMS I had to wait about 30 secs before it was ready to work. Normaly I wait only 1 or 2 secs.
I took a look in /proc/cpuinfo about it's clock. It was normal - about 500 mhz. I tried df -h about the free space.. it was more than 2 GBs (the whole linux partition is around 4GBs). I tried free -m about the memory usage. Without X I got around 43 MB (if that's the measure unit) free with total of 128MBs RAM. With X I got only 3 or 5 MBs free. Is that normal? I tried ps -AH, top and lsmod to find out what is loaded, and didn't find anything unusual. Any suggestions what should I do now?

cpu useage? (top followed by "P")

did you try......cat /proc/modules
and see what has loaded......you can do this as user or root

It is all tip-top today. Normal speed. Strange thing, though...