WD 640GB TOO SLOW?

[pi4]

Hey guys

When I copy files from one partition to another on the same DRIVE (WD 640GB Caviar Blue) the max speed is 45 MB/s .
Is that fast or too slow?


Any solution..


Thanks

 

[Soul_keeper]

That sounds about right. When copying you are both reading and writing at the same time. Assuming both your partitions are on the same drive you can roughly expect the copy speed to be 1/2 of the max sustained transfer rate. Move operations are generally faster (depending on the file system involved it can be near instant in the same partition), but across two different partitions you'd still have to read/write concurrently. If you are copying between two different drives then the operation will be much faster.

 

[pi4]

That sounds about right. When copying you are both reading and writing at the same time. Assuming both your partitions are on the same drive you can roughly expect the copy speed to be 1/2 of the max sustained transfer rate. Move operations are generally faster (depending on the file system involved it can be near instant in the same partition), but across two different partitions you'd still have to read/write concurrently. If you are copying between two different drives then the operation will be much faster.

Thank you

 

[sminlal]

That sounds about right. When copying you are both reading and writing at the same time. Assuming both your partitions are on the same drive you can roughly expect the copy speed to be 1/2 of the max sustained transfer rate.

Actually that's the very best you can expect under ideal conditions. In most cases the speed will be a lot slower than that because the head will have to continually seek back and forth between the file being copied from and the file being copied to. That's even more likely to be the case when you're copying between partitions since that usually forces the to and from files to be further apart on the drive.

 

[pi4]

But the speed is 45 MB/s when I move files from one partition to another.

 

[sminlal]

From a quick Google search it looks like the peak transfer rate for the 640GB WD Blue is about 110MByte/sec. When you copy from/to the same drive you're actually transferring 90MByte/sec (reading 45MByte/sec and writing 45MByte/sec). The other 20MByte/sec of potential performance is lost either because the data isn't at the outermost tracks where performance is best, or because the head is having to seek back and forth.

45MByte/sec is actually very good performance for copying between two partitions on the same hard drive. I suspect that either the files happen to be physically close together (for example, from a file at the end of the first partition to another one at the beginning of the second partition) or the files in question are small enough to fit in RAM cache.

 

[Soul_keeper]

yes, can always give a more detailed response

 

[pi4]

From a quick Google search it looks like the peak transfer rate for the 640GB WD Blue is about 110MByte/sec. When you copy from/to the same drive you're actually transferring 90MByte/sec (reading 45MByte/sec and writing 45MByte/sec). The other 20MByte/sec of potential performance is lost either because the data isn't at the outermost tracks where performance is best, or because the head is having to seek back and forth.

45MByte/sec is actually very good performance for copying between two partitions on the same hard drive. I suspect that either the files happen to be physically close together (for example, from a file at the end of the first partition to another one at the beginning of the second partition) or the files in question are small enough to fit in RAM cache.

For copying yes, but what about moving speed?
Is that enough cuz I have installed TeraCopy and the speed is45MB/s

 

[sminlal]

There's no difference between moving and copying except that when you do a move the input file is deleted as the very last step after the copy is finished.

Copy = read input file, write output file

Move = read input file, write output file, delete input file

 

[pi4]

I don't know, that's the only speed that TeraCopy shows, not even higher or lower speed.