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I got a new Dell laptop recently, with an i7 processor and 6GB RAM, with 2 320GB hard drives. I thought this machine would have a lot of horsepower, and in most respects it does.

But I find it to be very slow to transfer files between its two hard drives. I transferred about 100GB between the 2 drives recently, and it took hours. The transfer dialog box reported a transfer rate of 20 to 30 MB per second, which is ridiculous. I just did a test and it tkes about 12 seconds to transfer a 820 MB file, at about 60 or 70 MB per second.

Is this normal? I thought it would be much faster to transfer data between hard drives, like in the region of hundreds of MB per second. Is there something I could do to speed this up?

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Since it's a laptop - does it actually have two hard drives, or one drive with two partitions? – DMA57361 Aug 22 '10 at 16:37
@DMA also a good thing to point out. If it was 2 partitions that would cut your transfer rate down a fair bit as the actuator has to read and write to the same drive. – John T Aug 22 '10 at 16:49
I have 2 separate hard drives – DaveDev Aug 22 '10 at 17:51
up vote 1 down vote accepted
like in the region of hundreds of MB per second.

If that is what you're after, you'll want a SSD. Regular 5400rpm SATA drives (which is more than likely what your laptop has) will get the speeds you have reported. I'm assuming it is an ATA/66 interface meaning 66MB/sec.

Certain SSDs on the other hand will easily achieve 100MB/sec and higher:

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Hi John, thanks for the info. Just to note, the two drives are operating at 7200 rpm. Should I expect a performance improvement with this? – DaveDev Aug 22 '10 at 18:00
@Dave, Moreso than 5400rpm, but you still won't see write speeds in the 100's of MB per second. – John T Aug 22 '10 at 18:46
7200RPM will be faster but you really won't see more than maybe 80-90MB/s and that is on large files. If you are copying a lot of small files it will be a lot slower, similar to the range you experienced. The other thing to check is for bad sectors/SMART errors. I had a drive copy really slow and it ended up going bad a few hours later. But it was going at like 5MB/s so I doubt that you have a bad drive. – Nori Nov 30 '10 at 16:19

30MB/s really isn't that slow and it has nothing to do with processor / memory but more to do with the I/O controller chip.

All hard drives have fast burst/peak, so copying single files can be quick - what takes ages is either continued large file copies or many small files - e.g. 10,000,000 1KB (9,765MB) files should take a lot longer than a single 10GB files.

Sata 2 ports may advertise as 3GB/s, but the real throughput is no where near that!

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