Why is my computer taking so long to copy from one drive to another?

Question

I have two disk drives in my computer of about 120GB each. The 'C' drive has about 50Gb of data and the other drive (E) is almost empty. When I try and copy a large directory (65gb) from the 'C' drive to the E drive it take over 5 hours.

On my other machine this is achieved in about 30 mins or so.

I've tried copying from this machine to the other and that takes an age to complete.

Any suggestions as to what is going wrong, and how I can fix it?

Solution

If the drive is external via USB then you will be limited by the USB bus speed. USB2 drives tend to top out between 25 and 30Mbyte/sec, at 25Mbyte/sec g5Gb will take 45 minutes minimum. Some USB drives are slower then this (I had an old PATA->USB adaptor that won;t go above 10Mbyte/sec)

If you are copying many small files, or if the source disk is very badly fragmented, then you will not get close to the maximum transfer speed as the drive heads will be bouncing around all over the place (while the drive heads are moving from location to location no data can be transferred), unless of course both drives are decent SSDs. If it is a mix of large and small files you might find that it has started with a directory full of small ones so is estimating the total time using the speed it is copying them, and it will speed up once it hits the larger files.

Comments

[tombull89]

are the disks SATA or PATA/IDE?

[Jens Erat]

Are there really different disks or maybe partitions? Are you always copying the same data? Copying lots of small files takes much longer than copying few large ones. Both 5h and 30 minutes are reasonable values. How are you able to copy 65GB of data from a disk only containing 50GB of data?

[Jim]

Ops Sorry. The C drive had 75Gb of data not 50Gb. Jim

[Keltari]

you need to provide a lot more information. Are C: and E: partitions on the same drive, or are they two separate physical drives. what type of drives are they? SATA or IDE? how are they connected? SATA, IDE, USB? Comparing it another machine is apples and oranges and offers no useful information. Its like saying my Ferrari can drive from home to work in 30 minutes, but my Ford takes 5 hours. In other words, that is to be expected.

[Sirex]

unless its usb 3.0

[sawdust]

Operating on the same IDE channel is irrelevant. You cannot perform disk-to-disk transfers with IDE. Data will be disk-to-memory, and then memory-to-disk. (Some SCSI host-bus-adapters did have disk-to-disk transfer capability.)

[HaydnWVN]

In my experience copying from one drive to another on the same channel is certainly quicker than transfer between channels.

[Jim]

Both drives are IDE internal drives, but one is on the same channel as the CD Drive. I tried it on the IDE channel that the C drive is on but neither would work, and the interface cable is very short.

[Jim]

Not USB but both are internal IDE drives. They have both been defragmented and the E drive was also recently formatted as well. Diagnostics show them both as being 100%! It is true that there were lots of small files, but I have deleted them now and it still takes about the same time per Gb as before.