Slow Drive to Drive transfers- stalls sometimes.

Community Forums/General Help/Slow Drive to Drive transfers- stalls sometimes.

Amon(Posted 2011) [#1]
I have a big problem. When copying anything from one drive to another I get a transfer speed of just under 900kb. I have no idea what is causing it or why all of a sudden it started happening.

I'm using Microsoft Security Essentials and ZoneAlarm firewall. Don't diss ZoneAlarm firewall as it's the only free firewall out there that hasn't made my Windows Install go doollaly.

A bit more info: I have an external HD (USB) and another internal one but transfers are always slow, like I said around 900kb whether it's a bunch of small files or large files.

Has anyone got any ideas what could be causing it?


Yasha(Posted 2011) [#2]
Are both of the drives working correctly?

A disk that's had some physical problems may fall back to PIO mode if DMA isn't available, which is incredibly slow. You can check this in your device manager, in the IDE channel box.

It's a long shot, because I actually have no idea what the above paragraph means, or what PIO and DMA are, but it happened to me once and results in incredibly slow disk access.

Last edited 2011


D4NM4N(Posted 2011) [#3]
Is it an older PC?
It might be a silly question but it is not a USB 1 port is it? (or somehow running at mk1 speeds due to an incorrect USB driver or something? -and i mean the driver for the usb hw, not the drive itself)


big10p(Posted 2011) [#4]
I believe USB devices can share the available bandwidth equally between all devices. Try unplugging some USB devices and see if the transfer rate improves.


BlitzSupport(Posted 2011) [#5]
As Yasha suggests, I'd be checking if DMA is enabled for the internal drive/s. I don't think it's that long a shot, either, having been there myself. (If it's not in DMA mode, check if it's been disabled in the BIOS.)


xlsior(Posted 2011) [#6]
Could be a bum cable, too.

Another possibility: if its an older system with IDE drives, you may need to (re)install the IDE busmastering drivers.

It could also be a drive circling the drain - do you have s.m.a.r.t. enabled?


GfK(Posted 2011) [#7]
Could be a bum cable, too
That's a nasty mental image I really didn't want!


jsp(Posted 2011) [#8]
Was approx. 900kb not around the speed you got with a USB 1.1?
Could it be that the external drive or the computer hub limits the speed to that standard?
Does it show correctly in the Device Manager.


Floyd(Posted 2011) [#9]
You might try using a different USB port. I think I had an old PC with faster ports on the back of the machine.

On second thought the rear ports may just have provided more power.


xlsior(Posted 2011) [#10]
Very good point: USB 1/1 is 12 megabit, which is 1.5 megabyte/sec of raw speed *max*, shared among the other ports on the same controller... which could easily translate to 900kb/sec real world transfer speed.

My old computer had some ports that were USB 2.0, and some that were USB 1.1. Plugging it in a different port may very well make a difference, as does making sure you aren't using a USB 1.x hub.