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Disk copy is so slow

Posted: Fri Sep 21, 2012 8:53 am
by Iceman
Hey guys ... Long time, hope all is well with everyone. Anyway, I remember where I got my best tech help from so I came back for more ...

I've got a ThermalTake BLAC external SATA adapter with a brand new 2TB WD SATA disk w/a 64MB cache (WD2002FAEX). I'm copying about 200 Gb of data from my system disk (Similar but 1GB) and the copy dialog is showing a speed of 3.06 MB/sec ... Windows 7 Pro SP1 ... Any idea why this operation is so slow?

Re: Disk copy is so slow

Posted: Fri Sep 21, 2012 9:14 am
by CDN_Merlin
If they are small files that could be why. Bigger files take less time because there is less writing tot he FAT tables.

Re: Disk copy is so slow

Posted: Fri Sep 21, 2012 10:09 am
by Krom
I have one of those enclosures as well, although I quit using it as much after I upgraded to a pure eSATA enclosure. The peak sequential speed on it was about 35 MB/sec IIRC, but collections of smaller files go a lot slower because of the overhead. Try copying a big file (1+ GB) and see how quickly it moves. Otherwise try different cables/ports, make sure it isn't plugged into a hub, check the speed of the system drive, and try connecting the 2 TB drive to a regular SATA port to see if it improves any.

Re: Disk copy is so slow

Posted: Fri Sep 21, 2012 1:20 pm
by Iceman
Yeah, I was copying like 125,000 small files. When I went to copy a 12 Gb file it transferred lickety split ... I found the same behavior transferring from internal to internal.

Re: Disk copy is so slow

Posted: Fri Sep 21, 2012 2:05 pm
by fliptw
It would be faster to take the 125K files, and just add that to a zip file being created on the destination drive.

Re: Disk copy is so slow

Posted: Fri Sep 21, 2012 8:42 pm
by snoopy
Or... if you're feeling adventurous, using dd to copy an entire partition will go real fast.

Re: Disk copy is so slow

Posted: Fri Sep 21, 2012 10:10 pm
by Krom
3 MB/sec read from an internal 7200 RPM desktop drive is a pretty terrible number even for smallish files. 200 GB in 125,000 files would be an average of about 1.6 MB/file and any 1 TB 7200 RPM drive worth its salt should be able to spit out files that size without dropping under 50 MB/sec after overhead (even the first generation drives in the 1-2 TB range should hit close to 80 MB/sec just reading 128KB chunks). I'd start to think you have a serious fragmentation problem, when was the last time the drive was defragmented? (Windows 7 defaults to an automatic defragment schedule of once a week, but it only does it if the computer is left on so a lot of machines still miss it...)

Re: Disk copy is so slow

Posted: Mon Sep 24, 2012 6:55 am
by Iceman
The source or destination drive? The source could use defragging, the desintation is freshly formatted

Re: Disk copy is so slow

Posted: Mon Sep 24, 2012 8:22 am
by Krom
The source drive, "brand new" drives usually aren't fragmented.

Re: Disk copy is so slow

Posted: Mon Sep 24, 2012 2:48 pm
by Iceman
Will give that a shot, thanks man!