Messages in this thread | | | Date | Thu, 2 Jun 2005 16:37:44 -0400 | Subject | Re: External USB2 HDD affects speed hda | From | (Lennart Sorensen) |
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On Thu, Jun 02, 2005 at 03:11:12PM +0200, Rene Herman wrote: > Many thanks for trying but our systems really are quite different. I'm > on an old fashioned north/south-bridge system, where everything does > compete for bus bandwidth but on newer systems it's all some form of > "hub architecture" (intel nomenclature) or whatever nVidia calls it. I'm > not too familiar with it, but I do believe that on that system one > needn't really expect a misbehaving EHCI controller to have (much?) > effect on IDE throughput. > > Would you be willing to enable CONFIG_USB_DEBUG and then look at > /sys/class/usb_host/usbN/registers, for usbN your EHCI bus (the second > line of that file will say EHCI for that one)? Example for me:
I will try and do that when I get a chance. I can also try it on a machine with an add in ehci card (Via KT133 chipset + NEC ehci card).
> bus pci, device 0000:00:09.2 (driver 10 Dec 2004) > EHCI 1.00, hcd state 1 > structural params 0x00002204 > capability params 0x00006872 > status 0008 FLR > command 010009 (park)=0 ithresh=1 period=256 RUN > intrenable 37 IAA FATAL PCD ERR INT > uframe 2dee > port 1 status 001000 POWER sig=se0 > port 2 status 001000 POWER sig=se0 > port 3 status 001000 POWER sig=se0 > port 4 status 001000 POWER sig=se0 > irq normal 0 err 0 reclaim 0 (lost 0) > complete 0 unlink 0 > > When my IDE throughput is normal, the "status" line is always as above, > but after switching on the USB2 HDD (and even after switching if off > again and/or unplugging it) "Async" and/or "Recl" start toggling on and > off (and IDE throughput drops) until I rmmod ehci-hcd. You'd need to > check the file a few times in a row... > > In fact, anyone who could do the same would be much welcome. Certainly > with the EHCI controller on a PCI card, and even more certainly with a > VIA VT6212 EHCI controller on a PCI card.
> Your 41MB/s for the SATA disk on nForce2 does seem a bit low. The 50 > here is with a PATA Maxtor 120G on a UDMA66 controller. I just checked > and I see that with current kernels hdparm -a hasn't as much influence > as it used to have on the hdparm -t result, but try after a "hdparm -a N > /dev/sda" (sda for SATA, right?) for at least N = 256, 512, 1024, 2048 > and 4096...
Well the SATA is using an Sil3112A controller. Not sure how fast they are.
The system also isn't entirely idle, so who knows what might affect the speed. I only get 30M/s at the moment on the same type of WD 120G SATA drive on an ICH5R chipset, although I am pretty sure I have got more than that when it was idle before.
Len Sorensen - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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