I was hunted by this bug to but observed some behaviour that might help... I required a i386 12.10 desktop install for some rebuilds. Therefore I installed it on a VirtualBox install on my Intel Core i7-2600 CPU @ 3.40GHz with 32GB RAM. At first it ran fine, but since I was in a hurry doing full rebuilds, I assigned more RAM and cores to the VM instance. Since then I am suffering the same performance degredation.
At first I thought it just had to do with VirtualBox, so I installed the 12.10 i386 desktop natively on a build machine (Intel Core i5-2300 CPU @ 2.80GHz) with 16 GB RAM). After installation it ran fine for a while but then it also began to behave weird after I ran apt-get upgrade this morning. Since it ran initially fine on the VirtualBox instance, I recalled I changed the config. After restoring the settings to to what I think it used to be, all was fine. I have measured performance on my VirtualBox instance, varying ONLY the amount of assigned RAM. All other settings have been kept constant. I used time(1) to measure performance of 'sudo apt-get update'. I took 3 measurements, the times are below. I think it's safe to assume that the amount of RAM is of importance for this bug. I have not been able to test with a 64-bit kernel but it might not be reproducible with that. Please let me know if you require additional information about one of my systems. HTH, Mark Base Memory: 16384 MB Reading package lists... 42% <- aborted at this point real 9m42.187s user 0m7.952s sys 0m7.548s Base Memory: 15360 MB real 0m44.337s user 0m2.556s sys 0m1.096s Base Memory: 12288 MB real 0m10.399s user 0m1.192s sys 0m0.456s -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1107150 Title: B75 Chipset I/O Problems To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1107150/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs