hard disk speed regression (DMA is off)
Bug #72255 reported by
Tormod Volden
This bug report is a duplicate of:
Bug #71318: mkinitramfs doesn't include new pata drivers that switched from ide.
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Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux-source-2.6.19 (Ubuntu) |
Confirmed
|
High
|
Unassigned |
Bug Description
I am running 2.6.19-6-generic on an otherwise clean Edgy install. Everything feels slower, the mouse pointer is jerky, and booting time is slower (104s vs 64s).
Disk access (buffered) is slower in 2.6.19:
$ sudo hdparm -Tt /dev/hda
/dev/hda:
Timing cached reads: 616 MB in 2.00 seconds = 307.81 MB/sec
Timing buffered disk reads: 4 MB in 3.41 seconds = 1.17 MB/sec
versus 2.6.17:
$ sudo hdparm -Tt /dev/hda
/dev/hda:
Timing cached reads: 596 MB in 2.00 seconds = 297.95 MB/sec
Timing buffered disk reads: 50 MB in 3.04 seconds = 16.46 MB/sec
I have a SAMSUNG MP0804H, ATA DISK drive.
Changed in linux-source-2.6.19: | |
status: | Unconfirmed → Confirmed |
Changed in linux-source-2.6.19: | |
importance: | Undecided → High |
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(I am booting with init=/bin/bash to avoid any background activity.) Turning off DMA in .17 (hdparm -d0) gives the same speeds as in .19. hdparm -d in .19 reports 0 (off). Trying to enable it with hdparm -d1 gives:
HDIO_SET_DMA failed: Operation not permitted