I've some strange load issues, it randomly goes from 0.5 to 50-100, apache crashes (not always), then goes back to low again...

Backups are not running, even truned off crons so no scripts would be executed. Still same. No reason.

What issue could this be? Recompiled Apache, still same, changed API - same.

All I got from techs is:

"We are still watching this server to try and find out what is happening during that time. It happens pretty quickly, and seems to be MySQL related. "

No reply since then, did mysql optimization, other things, still same.

Could this be hardware issue? Could bad RAM cause that, anything? HDD? I've tried this command:

hdparm -Tt /dev/sda

/dev/sda:
Timing cached reads: 22584 MB in 2.00 seconds = 11305.02 MB/sec
Timing buffered disk reads: 6 MB in 4.03 seconds = 1.49 MB/sec < huh?

But they made some adjustements and said that it's 1500% better now, so I run and still says
Timing buffered disk reads: 6 MB in 3.63 seconds = 1.65 MB/sec

I'm totally confused. It's like random load or what so ever