Sometimes when I watch a recording, the picture becomes really pixellised and some frames are missing. RW and FF don't work correctly as well. When I tried to FF or RW , the image freezes. I have to wait several seconds to see it playing again.
It's not all the time. 10% or 20% of all my recordings.
When It happens, I can hear the hard drive scratching a lot.

This is the config. Everything is brand new. The RAM has been tested with memtest86+ for 8 hours with no problem.

M2NPV-VM
Athlon64 4600+
512 DDR2 667 (actually 384 with 128 shared with onboard video)
Western Digital 300 GB 16 MB cache ATA133

I thought it would be my hard drive, but I saw that I didn't have much RAM. Do you think my hard drive could be the problem or should I add more RAM or both?

When this occurs what does top show you?
If you play the same recording(s) later do you have the same problem? Are these HD or SD recordings?
Sounds like you may have a bottleneck in your drive I/O, have you enabled "slow deletes"?

Have you repaired/optimized your DB? A very large % of seek problems are caused by DB damage. Directions can be found in any of these places:
http://www.knoppmythwiki.org/index.php?page=RepairingMythConvergDB
http://mysettopbox.tv/phpBB2/viewtopic.php?t=15694
http://mysettopbox.tv/phpBB2/viewtopic.php?t=1043

You may also discover certain recording that you need to rerun mythcommflag with the appropriate options to rebuild the seek tables. The first link below includes directions. You should skip the restore step mentioned.
http://mysettopbox.tv/phpBB2/viewtopic.php?t=14002&highlight=mythcommflag&start=5
http://mysettopbox.tv/phpBB2/viewtopic.php?t=16549&highlight=mythcommflag+rebuild

I didn't run a top command. And actually, I don't know where to look where I run this command. I will run it next time and I will copy and paste it here.

I have the same problem, but it can appear at other moments in the recording.


All my recordings are SD.


I didn't change any settings, so if "slow deletes" is disabled by default, it still should be disabled.



No I haven't. I didn't think it could be a software problem. I was pretty sure it was a hardware problem. I'm gonna check all of this.



weird, I didn't receive any email notifications of your replies!

tjc: I just run the command to repair DB and I got no error. So the problem is elsewhere.

Open an Xterm (Alt-X) and execute top.

If you "can hear the hard drive scratching a lot" when this is occurring, enable the slow deletes. I forget where it is at the moment, somewhere in General of mythtv-setup I believe.

I know how to run "top". I meant I don't know what the values are for?

I will look for slow delete, and let you know