Disk throughput xcopying large files under Windows XP

[vitoprimo]

I have a Windows XP box with 2 hard drives installed on IDE primary using cable select as master and slave.

Both source and destination partitions have been defragmented. The source file is located contiguously on the source drive. When I use XCOPY to copy a large (13GB) file from one disk to the other the resulting throughput is roughly 6 megabytes per second.

This seems absurdly slow to me. During the xcopy the only programs running are Norton AntiVirus, Zone Alarm, and Task Manager. CPU utilization (measured using Task Manager) during the xcopy, which takes roughly 35 minutes, ranges from 5-35% with an average of about 25%.

The hardware is:
EPoX 8RDA+
512MB RAM
Athlon XP 1200
Primary IDE master: Maxtor 6Y1200L0
Primary IDE master transfer mode: Ultra DMA Mode 6
Primary IDE slave: Western Digital WD800JB
Primary IDE slave transfer mode: Ultra DMA Mode 5

Both drives spin at 7200 RPM and both have 8MB caches.

I was expecting a throughput rate in the vicinity of 20-30 MB/s.

 

[Smilin]

With those drives having probably 40MB/sec transfer rates 20-30MB/s is probably an unrealistic expectation.

You've got your drives both on the same IDE controller which means you can't simultaneously read from one drive and write to the other.

Try putting your 2nd drive on your second controller.

6MB/sec seems very low even for that setup, but definately try moving your drive and see what you get.

 

[lansalot]

You can realistically expect in the region of 11-12mb/s. As the man says, you can't read/write to both at the same time, so that's why you are approximately half your achievable rate.

 

[vitoprimo]

D'oh!

OK, I figured out what was wrong. It turns out, some months ago, I disabled the write cache on both drives. It dawned on me a little while ago so I re-enabled the cache on both drives and re-ran the xcopy procedure.

Throughput this time: 28.1 megabytes per second.

Gotta love that write cache.

Thanks folks for the feedback.