usb external much slower than internal HDD

[dethman]

my usb external 500gb is much slower than my internal drives, i know there should be a disparity, it's about 2-3x slower. my internal drive benches at around 60mb/sec peak, while usb is 20mb/sec.

to copy a 350mb file takes the internal about 7 sec, the usb around 18 seconds.

i know the usb 2.0 drivers are installed, and my other external 300gb drive with different enclosure also does the same. am i missing something?

 

[Fishbone Walker]

If you know there should be a disparity, what are you expecting?

 

[dethman]

there's TOO much of a disparity. usb 2.0 drives should run around 70-80% of internal speeds, but right now it's at around 30-40% which is very subpar.

 

[Budman]

Originally posted by: dethman
to copy a 350gb file takes the internal about 7 sec, the usb around 18 seconds.

holy ****** that's very fast. 350 gigs in 18 seconds??

that's very fast.

 

[dethman]

Originally posted by: Budman

Originally posted by: dethman
to copy a 350gb file takes the internal about 7 sec, the usb around 18 seconds.

holy ****** that's very fast. 350 gigs in 18 seconds??

that's very fast.

sorry. mb.

 

[LOUISSSSS]

does your external have 2 x usb connectors for the pc? if yes, u should connect both as i read that both are used to transfer files and to supply hdd with power

 

[dethman]

Originally posted by: LOUISSSSS
does your external have 2 x usb connectors for the pc? if yes, u should connect both as i read that both are used to transfer files and to supply hdd with power

no, all enclosures i have seen have one. power is supplied by an ac adapter.

 

[RebateMonger]

I use a LOT of USB backup drives. I used to believe the estimates (26 Megabytes per second) about USB 2.0 speed. And I'd never actually TIMED any large backups. But recently I've actually timed some LARGE (300GB) backups, and found that USB 2.0 runs about 10 Megabytes per second when running Windows NTBackup. That's a LOT slower than internal IDE drives are capable of.

These numbers come from several Server 2003 servers with SCSI RAID 1 or RAID 5 drive arrays, USB 2.0 connections, and several brands of factory USB 2.0 drives. These were both typical system backups, and backing up large numbers of data files.

 

[ForumMaster]

well technically USB 2 is rated at 480Mbps which is 60MBps. say 45-55MB for best case. you say you're only getting 20MB? have you tried a different port? is it connected to a hub? try connecting directly to your computer.

 

[dethman]

Originally posted by: ForumMaster
well technically USB 2 is rated at 480Mbps which is 60MBps. say 45-55MB for best case. you say you're only getting 20MB? have you tried a different port? is it connected to a hub? try connecting directly to your computer.

no hubs. directly to the motherboard. i was expecting around 45MB/sec realistically. i'm running an abit nf7-s 2.0 so it's not a cheap motherboard issue. cpu utilization is only 4% so it's not that. i'm stumped.

 

[w00t]

it's external even if you have usb 2.0 it's not going to be as fast as SATA or PATA

 

[corkyg]

Typical maximum sustained data transfer rates:

USB 2.0 = 40 MBps
IDE PATA = 74 MBps

Both have higher burst rates. I would say that those opimum numbers are pretty close to 2X. There are variances in brands of drives.

Firewire will out perform USB 2 on a sustained data transfer basis.

 

[kmrivers]

Firewire FTW!