Memory upgrade makes Ubuntu painfully slow
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
NULL Project |
Invalid
|
Undecided
|
Unassigned | ||
grub2 (Ubuntu) |
Invalid
|
Undecided
|
Unassigned | ||
Oneiric |
Invalid
|
Undecided
|
Unassigned | ||
linux (Ubuntu) |
Fix Released
|
Low
|
Andy Whitcroft | ||
Oneiric |
Fix Released
|
Low
|
Andy Whitcroft |
Bug Description
When upgrading the system memory of an Acer Veriton 1000 from 1GB to 2GB, the Ubuntu 11.04 operating system becomes unusable slow. The problem is reproducible and only occurrs when both memory modules are inserted (operation in dual-channel mode). When booting from the live CD the problem does not occur, only when booting the operating system from hard disk after installation. When booting from the live CD, the hard drive can also be mounted and accessed with normal performance.
The following diagnostic steps have already been performed:
- upgraded system BIOS to latest version available
- tried different memory modules (same outcome)
- run memtest86 (all memory ok)
- run ubuntu and other Linux from live CD (works ok)
- installed Windows XP on hard drive (boots and runs with normal performance)
- installed Fedora Linux 15 on hard drive (boots and runs with normal performance)
More information:
- Performance is already very slow at the Ubuntu Grub Bootloader Menu (before OS kernel is loaded): takes about 20 seconds to draw the main screen, 20 more seconds to draw the edit screen when using "e" button on a grub list element
- Besides the very poor performance no errors are shown; OS can also be booted in about 10mins (instead of 30 seconds when only one mem module is inserted)
- When OS is booted, bottleneck seems to be disk I/O, but hard disk activity is only very low; no kernel / system errors visible, system responsiveness also ok as long as no disk access happens.
I suspect Ubuntu to apply some special settings already at GRUB bootloader level when installing to a hard drive, or access memory in a special way. These "settings" seem not to be compatible with the systems dual channel memory access mode.
Please inform me when any additional information is required, I'll be glad to provide.
Kind regards,
H.
affects: | ubuntuone-dev-tools → ubuntu-community |
affects: | ubuntu-community → null |
Changed in null: | |
status: | New → Invalid |
Changed in linux (Ubuntu): | |
assignee: | nobody → Andy Whitcroft (apw) |
status: | Confirmed → In Progress |
Changed in linux (Ubuntu Oneiric): | |
status: | In Progress → Fix Committed |
importance: | Undecided → Low |
tags: | removed: 1000 channel dual grub io memory upgrade veriton |
Changed in grub2 (Ubuntu): | |
status: | New → Invalid |
Changed in grub2 (Ubuntu Oneiric): | |
status: | New → Invalid |
I could not find a project to attach this issue to, looking for someone with knowledge about Ubuntu bootloader concept / details.