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On Fri, 2011-01-14 at 19:06 +0100, Josef Wolf wrote:
Hello folks.
I am trying to track a performance bottleneck on the USB interface. The strange thing is that I sometimes get good performance and other times bad performance.
For example, I have a memory stick which should go about 5MB/s for write.
From this stick, I sometimes get the promised 5MB/s. But sometimes I get only about 120kb/s. It is the same stick, plugged into the same port, without reboots. But for some strange reason, sometimes it is recognized as a "full speed device" (this is the slow mode) and sometimes as a "high speed device" (this is the fast mode). Please check the two excerpts from /var/log/messages below.
This is opensuse-11.2 running on a 2GHz Athlon dual core 4850e with USB2.0 on-board.
Any ideas?
Jan 13 17:15:42 raven kernel: [4988831.356060] usb 6-3: new full speed USB device using ohci_hcd and address 10 Jan 13 17:15:42 raven kernel: [4988831.496420] usb 6-3: not running at top speed; connect to a high speed hub Jan 13 17:15:42 raven kernel: [4988831.508147] usb 6-3: New USB device found, idVendor=1307, idProduct=0165 Jan 13 17:15:42 raven kernel: [4988831.508191] usb 6-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 Jan 13 17:15:42 raven kernel: [4988831.508208] usb 6-3: Product: USB Mass Storage Device Jan 13 17:15:42 raven kernel: [4988831.508226] usb 6-3: Manufacturer: USBest Technology Jan 13 17:15:42 raven kernel: [4988831.508243] usb 6-3: SerialNumber: 00000000000025 Jan 13 17:15:42 raven kernel: [4988831.508513] usb 6-3: configuration #1 chosen from 1 choice Jan 13 17:15:42 raven kernel: [4988831.510720] scsi16 : SCSI emulation for USB Mass Storage devices Jan 13 17:15:42 raven kernel: [4988831.511044] usb-storage: device found at 10 Jan 13 17:15:42 raven kernel: [4988831.511051] usb-storage: waiting for device to settle before scanning Jan 13 17:15:43 raven kernel: [4988832.519175] scsi 16:0:0:0: Direct-Access Ut165 USB2FlashStorage 0.00 PQ: 0 ANSI: 2 Jan 13 17:15:43 raven kernel: [4988832.532181] usb-storage: device scan complete Jan 14 07:26:51 raven kernel: [5039900.748961] usb 6-3: USB disconnect, address 10
Jan 14 18:47:12 raven kernel: [5080721.042097] usb 2-6: new high speed USB device using ehci_hcd and address 8 Jan 14 18:47:12 raven kernel: [5080721.158891] usb 2-6: New USB device found, idVendor=1307, idProduct=0165 Jan 14 18:47:12 raven kernel: [5080721.158936] usb 2-6: New USB device strings: Mfr=1, Product=2, SerialNumber=3 Jan 14 18:47:12 raven kernel: [5080721.158953] usb 2-6: Product: USB Mass Storage Device Jan 14 18:47:12 raven kernel: [5080721.158971] usb 2-6: Manufacturer: USBest Technology Jan 14 18:47:12 raven kernel: [5080721.158988] usb 2-6: SerialNumber: 00000000000025 Jan 14 18:47:12 raven kernel: [5080721.159415] usb 2-6: configuration #1 chosen from 1 choice Jan 14 18:47:12 raven kernel: [5080721.170350] scsi17 : SCSI emulation for USB Mass Storage devices Jan 14 18:47:12 raven kernel: [5080721.170657] usb-storage: device found at 8 Jan 14 18:47:12 raven kernel: [5080721.170664] usb-storage: waiting for device to settle before scanning Jan 14 18:47:13 raven kernel: [5080722.171201] scsi 17:0:0:0: Direct-Access Ut165 USB2FlashStorage 0.00 PQ: 0 ANSI: 2 Jan 14 18:47:13 raven kernel: [5080722.172581] usb-storage: device scan complete
Silly question: are you plugging it in to the exact same USB connector each time? One says 'ohci_hdc' and the other says 'ehci_hdc'. So different drivers are used. That would only happen if there was different USB hardware involved. -- Roger Oberholtzer OPQ Systems / Ramböll RST Ramböll Sverige AB Krukmakargatan 21 P.O. Box 17009 SE-104 62 Stockholm, Sweden Office: Int +46 10-615 60 20 Mobile: Int +46 70-815 1696 SHAW'S PRINCIPAL Build a system that even a fool can use, and only a fool will want to use it. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org