USB 2.0 external HDD transfer rate too slow

[Guest]

I am running Kubuntu 8.04 on a Dell Latitude c610. My machine only has one USB 1.1 port, so I am using a PCMCIA USB 2.0 cardbus with a VIA chipset. The good news is everything I have plugged into the card has worked. The problem is it only works at USB 1.1 speed. Actual file transfer rates are around 700 K/s. This is true of USB 2.0 HDD and USB 2.0 flash drives. I have already made sure they are not mounted synchronous. How do I get high speed transfer rates? Here are the details:

matt@matt-laptop:~$ sudo hdparm -t /dev/sdb                   
[sudo] password for matt:                            

/dev/sdb:
 Timing buffered disk reads:  4 MB in 3.62 seconds =  1.10 MB/sec
matt@matt-laptop:~$ sudo hdparm -t /dev/sdb             

/dev/sdb:
 Timing buffered disk reads:  6 MB in 4.84 seconds =  1.24 MB/sec
matt@matt-laptop:~$ sudo hdparm -t /dev/sdb             

/dev/sdb:
 Timing buffered disk reads:  6 MB in 4.04 seconds =  1.48 MB/sec
matt@matt-laptop:~$ sudo hdparm -T /dev/sdb             

/dev/sdb:
 Timing cached reads:  86 MB in 2.00 seconds = 42.93 MB/sec
matt@matt-laptop:~$ sudo hdparm -T /dev/sdb          

/dev/sdb:
 Timing cached reads:  74 MB in 2.00 seconds = 36.93 MB/sec
matt@matt-laptop:~$ sudo hdparm -T /dev/sdb          

/dev/sdb:
 Timing cached reads:  74 MB in 2.01 seconds = 36.79 MB/sec
matt@matt-laptop:~$ sudo lsusb                 
Bus 004 Device 002: ID 04cf:8818 Myson Century, Inc. USB2.0 to ATAPI Bridge Controller                                     
Bus 004 Device 001: ID 0000:0000                        
Bus 003 Device 001: ID 0000:0000                        
Bus 002 Device 001: ID 0000:0000                        
Bus 001 Device 001: ID 0000:0000                        
matt@matt-laptop:~$ sudo lspci | grep -i usb
00:1d.0 USB Controller: Intel Corporation 82801CA/CAM USB Controller #1 (rev 02)
03:00.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 61)                                    
03:00.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 61)                                    
03:00.2 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 63)

matt@matt-laptop:~$ sudo dmesg | grep -i usb                  
[  21.758718] usbcore: registered new interface driver usbfs          
[  21.758770] usbcore: registered new interface driver hub           
[  21.782558] usbcore: registered new device driver usb            
[  21.809878] USB Universal Host Controller Interface driver v3.0       
[  21.810558] uhci_hcd 0000:00:1d.0: new USB bus registered, assigned bus number 1                                       
[  21.810879] usb usb1: configuration #1 chosen from 1 choice         
[  21.810931] hub 1-0:1.0: USB hub found                    
[ 785.174112] uhci_hcd 0000:03:00.0: new USB bus registered, assigned bus number 2                                       
[ 785.174460] usb usb2: configuration #1 chosen from 1 choice         
[ 785.174543] hub 2-0:1.0: USB hub found                    
[ 785.277783] uhci_hcd 0000:03:00.1: new USB bus registered, assigned bus number 3                                       
[ 785.278151] usb usb3: configuration #1 chosen from 1 choice         
[ 785.278221] hub 3-0:1.0: USB hub found                    
[ 576.553708] ehci_hcd 0000:03:00.2: new USB bus registered, assigned bus number 4                                       
[ 576.563508] ehci_hcd 0000:03:00.2: USB 2.0 started, EHCI 1.00, driver 10 Dec 2004                                      
[ 576.564219] usb usb4: configuration #1 chosen from 1 choice         
[ 576.564520] hub 4-0:1.0: USB hub found                    
[ 788.941148] usb 4-4: new high speed USB device using ehci_hcd and address 2 
[ 788.988045] usb 4-4: configuration #1 chosen from 1 choice          
[ 789.291091] usbcore: registered new interface driver libusual        
[ 789.428086] Initializing USB Mass Storage driver...             
[ 789.431374] scsi2 : SCSI emulation for USB Mass Storage devices       
[ 789.437824] usbcore: registered new interface driver usb-storage       
[ 789.438350] USB Mass Storage support registered.               
[ 789.438871] usb-storage: device found at 2                  
[ 789.438880] usb-storage: waiting for device to settle before scanning    
[ 790.526691] usb-storage: device scan complete

[linuxlvr]

Re: USB 2.0 external HDD transfer rate too slow

u stated your answer.
your machine only supports 1.1
that limits your hdd to 1.1 even tho its capable of going to 2.0

[Guest]

Re: USB 2.0 external HDD transfer rate too slow

Is it correct that USB 1.1 transfers top out at 12MB/s? If so, why are the transfer rates 700KB/s? Under windows with all the same hardware transfers were usually 10-15MB/s, so I know the machine is capable of more. Any other ideas? If I disable ehcl and force full-speed rather than high-speed will I be able to get full-speed transfers rather than these sub-low-speed rates? I have exhausted my own abilities where this is concerned, so any help is greatly appreciated.

[dibl]

Re: USB 2.0 external HDD transfer rate too slow

USB transfer rates:

http://www.everythingusb.com/usb2/faq.htm

It's unlikely that the one USB port is going to run at 100% rate just for your test, given the other tasks that the OS has to take care of. But yes, it should approach the USB 1.1 speed, assuming the other hardware in the daisy chain can support it.

Also, don't confuse Mbits with Mbytes -- a little obfuscation that creeps in at every opportunity. Read 'em carefully.