Messages in this thread | | | Date | Wed, 5 Mar 2008 01:27:30 +0300 (MSK) | From | "Lev A. Melnikovsky" <> | Subject | ehci-hcd affects hda speed |
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Hi,
I have recently installed a VT6212L-based PCI USB controller into my old rock-stable P3B-F computer just to discover that, even being idle, it significantly slows down main PATA hard drive. I have found an earlier thread with similar (?) problem (archived at http://marc.info/?t=111749614000002&r=1&w=2 ) but it provides no solution. Can this behaviour be explained? Can it be fixed?
There's one thing that makes me optimistic: USB traffic _speeds_up_ hda. That is hdparm gives ~20% improvement in buffered reads if a USB flash is inserted and another xterm simultaneously runs # dd if=/dev/sda of=/dev/null bs=1024
Here's what I see:
------------------------------------------------------------------------------ # hdparm -t -T /dev/hda /dev/hda: Timing cached reads: 312 MB in 2.01 seconds = 155.60 MB/sec Timing buffered disk reads: 88 MB in 3.06 seconds = 28.77 MB/sec # modprobe ehci-hcd # hdparm -t -T /dev/hda /dev/hda: Timing cached reads: 274 MB in 2.01 seconds = 136.58 MB/sec Timing buffered disk reads: 44 MB in 3.10 seconds = 14.20 MB/sec # rmmod ehci-hcd # hdparm -t -T /dev/hda /dev/hda: Timing cached reads: 286 MB in 2.01 seconds = 142.48 MB/sec Timing buffered disk reads: 90 MB in 3.06 seconds = 29.44 MB/sec ------------------------------------------------------------------------------
And here's what I have (kernel 2.6.24.3):
------------------------------------------------------------------------------ #lspci -v
00:09.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 62) (prog-if 00 [UHCI]) Subsystem: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller Flags: medium devsel, IRQ 5 I/O ports at d000 [size=32] Capabilities: [80] Power Management version 2
00:09.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 62) (prog-if 00 [UHCI]) Subsystem: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller Flags: medium devsel, IRQ 9 I/O ports at b800 [size=32] Capabilities: [80] Power Management version 2
00:09.2 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 65) (prog-if 20 [EHCI]) Subsystem: VIA Technologies, Inc. USB 2.0 Flags: bus master, medium devsel, latency 32, IRQ 11 Memory at d3800000 (32-bit, non-prefetchable) [size=256] Capabilities: [80] Power Management version 2
# cat /proc/interrupts CPU0 0: 100814528 XT-PIC-XT timer 1: 4057 XT-PIC-XT i8042 2: 0 XT-PIC-XT cascade 3: 1013 XT-PIC-XT 4: 2 XT-PIC-XT 5: 7165568 XT-PIC-XT bttv0, FM801, uhci_hcd:usb2, uhci_hcd:usb3 8: 25956003 XT-PIC-XT 9: 661413 XT-PIC-XT eth1, uhci_hcd:usb4 10: 4 XT-PIC-XT 11: 13526145 XT-PIC-XT eth0, ehci_hcd:usb1 12: 1068179 XT-PIC-XT i8042 14: 710123 XT-PIC-XT ide0 15: 4365 XT-PIC-XT ide1 NMI: 0 Non-maskable interrupts TRM: 0 Thermal event interrupts SPU: 0 Spurious interrupts ERR: 0 ------------------------------------------------------------------------------
Please let me know if I missed something important.
Thanks -L
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