W8CCW said:
Yesterday evening I discovered that I have not getting the backup that
I want out of SyncToy. To facilitate working on the problem I decided
to offload the current backup to a spare 1 TB drive in the same box. I
created a folder called Drive E, did a control A select in Win 7
Explorer, click on Copy, and select folder Drive, click on Paste and
here we are 19 hours later waiting for 250 G to be transfered.
Both drives are Seagate SATA on the same MSI MB. Is this normal?
To "bound" or tell you how bad a drive can be, consider the transfer
rate achieved when you defragment a drive.
One of my OSes, does that at around 1MB/sec. My best case is around 3MB/sec
(on another computer, with a different Windows OS). The reason those speeds
happen, is the transfer size is tiny, and there is a lot of head movement
per megabyte of data. During defrag, the disk head flies around like crazy.
If your drive has many small files, transfer rates are going to suck just
like defragmenting does.
If the drive was say, your "movie" drive, and there were a relatively
small number of gigabyte sized files, then something is seriously wrong.
On the one hand, it's possible to have extreme fragmentation. One way
to achieve that, would be to have a quad TV tuner in the PC, and record four
TV programs at the same time. That could cause the four, gigabyte sized
recorded files, to have thousands of fragments. Copying severely fragmented
files (just freshly recorded), would suck in the same way as our small file
example would, because the disk head has to move to find every fragment.
Smooth contiguous files, written with no other interference at the time,
can transfer at 125MB/sec+.
What I use for disk to disk transfer, is Robocopy. I use the command line,
but there is also a GUI. Note that, that tool is extremely dangerous, when
doing things like the "mirror" option. Mirror would erase any destination
folder contents not needed to mirror the source disk. If you accidentally
point the mirror operation at the wrong drive, you lose the contents
of the destination drive. I've had just one accident with Robocopy so
far, and had to modify my procedures a bit so it won't happen again.
http://technet.microsoft.com/en-us/magazine/2006.11.utilityspotlight.aspx
Robocopy does non-blocking I/O, and can issue read and write requests at
the same point in time (to two different drives). So it can overlap
commands. I find it generally good, and achieves an average of perhaps 40MB/sec
with my crappy $50 drives here. That's an average - transfer rate can vary
from 3MB/sec (doing the small files again) to 125MB/sec (copying my pagefile
or hiberfile on an OS partition). The long term average while copying
thousands of files, is in the 40MB/sec ballpark. If I copy A-->B then
B-->A, I usually get a *different* average value - don't ask me why.
That happened even when disk A is exactly the same model number as disk B.
If we do the math for you, 250GB is 250000MB in 19*60*60 seconds or
250000/68400 = 3.65MB/sec, which would be fine if you had a million
small files on the drive. You may find Robocopy does a little better -
I think it's a lot better than the file system copy routine, for
comparison.
Just for the record, this is a typical command line I use for moving the
entire contents from one partition to another. I run this in an MSDOS
(command prompt) window. I keep a logfile for each transfer, mainly
to compare the numbers at the end of the log. If copying a partition off
to another partition, then back again, I like to verify I got all the files.
robocopy L:\ E:\ /mir /copy:datso /dcopy:t /r:3 /w:2 /zb /np /tee /v /log:robocopy_ell_to_e.log
Typical log results:
****************************************
-------------------------------------------------------------------------------
ROBOCOPY :: Robust File Copy for Windows :: Version XP026
-------------------------------------------------------------------------------
Started : Tue Sep 06 20:23:59 2011
Source = L:\
Dest = E:\
Files : *.*
Options : *.* /V /TEE /S /E /COPY
ATSO /DCOPY:T /PURGE /MIR /ZB /NP /R:3 /W:2
------------------------------------------------------------------------------
NOTE : NTFS Security may not be copied - Source may not be NTFS.
NOTE : NTFS Security may not be copied - Destination may not be NTFS.
26 L:\
same 2.9 g hiberfil.sys
same 2.0 g pagefile.sys
...
Total Copied Skipped Mismatch FAILED Extras
Dirs : 14376 14375 1 0 0 0
Files : 178733 178731 2 0 0 0
Bytes : 39.895 g 34.896 g 4.999 g 0 0 0
Times : 0:29:50 0:16:06 0:00:00 0:13:44
Speed : 38778320 Bytes/sec. <--- my long term average copy rate
Speed : 2218.913 MegaBytes/min.
Ended : Tue Sep 06 20:53:50 2011
****************************************
Paul