Re: External USB2 HDD affects speed hda

[Lennart Sorensen]

On Thu, Jun 02, 2005 at 12:14:16AM +0200, Rene Herman wrote:
> Sound scary. Must say I do generally have a lot of faith in this chipset 
> (AMD751/756). The machine's been as stable as a rock for years now. A 
> logic analyser I do not have, nor the ability to interpret it if I did.
> 
> I did just now try two different PCI slots. Again no change.
> 
> Erhhm. rmmoding ehci-hcd works. I suppose it tells the hardware to shut 
> up on module_exit. is there any way to have it tell the hardware the 
> same while keeping it loaded? Any other ideas?

I just tried pluging in my usb2 flash reader which ought to d the same
thing to usb-storage as pluging in the external usb2 hd.

Reading from a 120G SATA WD drive gets about 41MB/s without the USB2
drive connected and about the same with.  That is on an nforce2
motherboard with it's builtin usb controller and using 2.6.10.

Trying on an Athlon64 with a 250G SATA WD drive and the same usb flash
reader, I get 57MB/s both with and without the usb2 drive connected.
That one uses a VIA K8T800 chipset and also 2.6.10.

I wonder what is different with your hardware/software mix.

I tried unloading everything to do with usb to try and see if I could
make it get a higher speed with hdparm, but no change no matter what.

Len Sorensen
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