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rj
11-15-2014, 07:26 PM
So I was moving multiple gigabytes from one file to another, and I noticed if I had 4 running it would be insanly slow, as in 2-3 MB/ps. At first I thought "I have a multicore computer, copying multiple files shouldn't take any longer" until I remember that I was a idiot and it's using the harddrive (I think my harddrive speed is 5400 or 7200 RPM, I know it's just average speed nothing fast, I also have a SSD built in the computer but it's only 21 GB useable)

So I paused all copying except for 1 file, and I noticed it stays at a flat 21-23 Mb/ps for the most part but sometimes it jumps all the way up to 60 mb/ps. How can I get it to consistently stay at those speeds?

http://i.imgur.com/dRNQZw5.png

I wasn't running anything else, any explanation as to why is randomly triples speed?

bonsai
11-15-2014, 08:12 PM
That average speed is about what you can get out of your setup.

The peaks are a little bit of lol windows and a little bit of random chance. It's not a sustainable rate.

If you set up a perfect disk test by doing sequential read/writes and having everything tuned just right you can get the highest numbers from a setup but real life is what it is.

If your files are defragmented copies will probably go faster since the disk head will (most likely) need to move around a lot less. If the file is scattered all over the place, you lose much of your time to repositioning the disk and it does not get close to maximum speed.

This is probably why your multiple copies dogged out the system. You were asking it to run the disk all over the place reading and writing things and pushed it into the lowest performance.

rj
11-15-2014, 08:18 PM
That average speed is about what you can get out of your setup.

The peaks are a little bit of lol windows and a little bit of random chance. It's not a sustainable rate.

If you set up a perfect disk test by doing sequential read/writes and having everything tuned just right you can get the highest numbers from a setup but real life is what it is.

If your files are defragmented copies will probably go faster since the disk head will (most likely) need to move around a lot less. If the file is scattered all over the place, you lose much of your time to repositioning the disk and it does not get close to maximum speed.

This is probably why your multiple copies dogged out the system. You were asking it to run the disk all over the place reading and writing things and pushed it into the lowest performance.

How much faster do you think a 7200 RPM harddrive would be compared to 5400?

Home
11-15-2014, 08:27 PM
You could always try Robocopy with threads.

-Home

bonsai
11-15-2014, 08:30 PM
How much faster do you think a 7200 RPM harddrive would be compared to 5400?

Probably not much, maybe another 10MB/s. The speeds you're getting sound about average for a 7200rpm desktop to me. 20-30MB/s ave, 40-60 peak.

Some drives are better than others, they do all sorts of things to speed them up. So there are 7200rpm drives that perform better but they cost more.

Solid state or raid/caching are where you get the big improvements.

rj
11-15-2014, 10:15 PM
Probably not much, maybe another 10MB/s. The speeds you're getting sound about average for a 7200rpm desktop to me. 20-30MB/s ave, 40-60 peak.

Some drives are better than others, they do all sorts of things to speed them up. So there are 7200rpm drives that perform better but they cost more.

Solid state or raid/caching are where you get the big improvements.

Yea, I tested copying a file on my SSD and it was 1.5 GB/s for like half a second then it just went down to 50 MB/s

Wish it was bigger though, can't afford to get one that would replace my harddrive

acow
11-18-2014, 06:32 PM
Yeah it sucks, my HDD's performance is starting to wane, sometimes my bandwidth isn't even my limiting factor for downloads but rather "writing to disk" is (100+ mbps home connection ^_^)