The primary symptom is that apps frequently freeze up, graying out. I've read that the gray is a visual signal from compiz for apps that have become unresponsive.
It happens so often that the machine is basically unusable. Every time I interact with an X app, e.g. Firefox and Software Center, they will freeze and go gray. The freeze is system modal: alt-tab doesn't work, so I just have to wait it out. The mouse usually moves, but sometimes not. I'd say 90% of the time the mouse is movable.
I've come to expect waiting at least 30 seconds per freeze before I can use the machine again, often longer. If I scroll a web page, enter a new URL or use a search engine. If I search Software Center, install an app. XTerm is the only exception- it never freezes.
Heck, I've left this machine sitting next to my desktop while I do other work, and have noticed Firefox will grey out the top window every few minutes! All on its own, without me even near the machine.
top shows that compiz is frequently busy, occupying 40-100% of a core. I also experimented with disabling OpenGL in compiz's config mgr, thinking that maybe this machine doesn't have a proper accelerated GPU (doubtful) and that it's emulating the accelerated window mgr features, but found no difference in performance.
I'm about ready to scrap this install, and move to Lubuntu, Mint or some similar lighter distro, in the hopes this situ will improve.
I installed 12.10 onto a Kingston 16GB thumb drive, changed the BIOS boot order, and boot from that. The Q200E came with Windows 8 on a 500GB HD. I've run that a few times, and it never lags like this Ubuntu installation, but I've only surfed the web with it.
Any help appreciated.
- Ubuntu 12.10 64-bit, kernel 2.5.0-17-generic (uname also says "Ubuntu SMP")
- Intel i3 @ 1.4 GHz
- 4GB RAM (1.5-2.0 GB in use typically, per top)
- 4GB swap (0 in use, it's never been touched)
- Kingston 16GB drive; reads at 23 MB/s; writes at 4 to 5 MB/s (per dd)
- It's not a super-slow machine, the benchmarks are okay and the bus speed isn't awful (df if=/dev/zero of=/dev/null bs=1M count=1000 (10GB) 1.55482s, 6.7 GB/s (for comparison, my i7 desktop runs this in 0.635 secs, about 2.5 times faster) )
- dmesg shows no obvious errors, all cores available, memory good