Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Why is my computer lagging everytime I try to simply copy (or move to another disk which I think is the same as copying anyway) 200 GB of file from my C:\ drive to the E:\ drive (external hard disk) ?

I mean I opened the Task Manager and

Going to process it shows explorer.exe - 14k. Doesn't look like a big problem with Ram. But I noticed that everytime I try to copy files like 200 GB my computer will be laggy.

What's the cause of the lag here?

(Windows Vista Home Premium sp2)

share|improve this question
Can you please provide your external HDD specs, and your internal HDD specs – wizlog Sep 1 '11 at 3:24
I'll take a stab at your virus protection scanning the file before it lets it copy. Try disabling virus protection temporarily and see if that makes a difference. – Hand-E-Food Sep 1 '11 at 3:26
@wizlog i'm using this external:… – Pacerier Sep 1 '11 at 3:34
@wizlog i don't know how to get the internal HDD specs do you mean this: 500GB HDD DVD-Super Multi DL 802.11a/b/g/Draft-N 3x3 WLAN 4GB DDR3 – Pacerier Sep 1 '11 at 3:35
@Hand i don't have any virus protection installed and i have firewall and defender permanently off. – Pacerier Sep 1 '11 at 3:36
up vote 1 down vote accepted

It could be that the HDD's cache or buffer isn't that large, and/or that the drives need to be defragmented.

I would recomend splitting the files your trying to copy, using Winrar or HJSplit.

I would also close all other programs that read/write lots of data, ex. compression software, video editing software...

You can also try to use software called TeraCopy. Its faster, and it can pause (in case you need to use your computer lag free in the meantime.

share|improve this answer
I never said to click format or anything... – wizlog Sep 1 '11 at 14:50

Everytime I try to copy files like 200 GB my computer will be laggy

The hard disk is the slowest part of most any computer system, and you just told yours to spend the next several minutes (or longer) copying a very large file. The result is taking the biggest bottleneck to system performance and making it even worse.

share|improve this answer
Is there a way to tell the system that it's ok to take 2 times longer to do the transfer but use half the resources so it doesn't bog down my computer? – Pacerier Sep 1 '11 at 5:16
@Joel, copying from the hard disk shouldn't slow down the Explorer GUI. That's a background process to my knowledge. – Hand-E-Food Sep 1 '11 at 5:23
@Hand - "background process" just means it plays nice with the cpu. It's still easy for this kind of thing to peg your disk i/o. – Joel Coehoorn Sep 1 '11 at 15:13
@Joel, I get that, but why would Disk IO interrupt the GUI? Unless there's a lot of paging going on, I'd have thought the Disk IO would have so much down time that other processes would have plenty of CPU time available. – Hand-E-Food Sep 1 '11 at 23:48
@JoelCoehoorn isn't the computer supposed to be smart about it and not use 100% of it's power doing the copy? – Pacerier Sep 24 '11 at 12:15

I had the similar problem with my external HDD. When I tried to copy/move the files like 20-50 GB I got just 15-18 Mb/s transfer speed and system also so slow. I thought it is my system fault but whenever I copy/move on the internal HDD it was giving me the best performance with 25-30 Mb/s transfer speed.

I checked my external HDD on friends system and the same problem was there too then I took the backup of my data which was on external HDD and delete all the partitions have on it and recreated them using Easeus Partition manager. And this wass a miracle my laptop is giving fine performance with 25-32 Mb/s transfer speed on my External HDD.

So lets take a try with backup your external HDD data and then delete the partition and Recreate them.

share|improve this answer
I don't understand with the partition part. I've not modified it since I've bought it so it's basically not partitioned? or do you mean I should do a format? – Pacerier Sep 1 '11 at 5:14
Yes I mean that. If you have not partitioned it its depend on your use. I just suggest you to do so. And delete the E: partition(if it is only available partition on your external HDD) and recreate it. – avirk Sep 1 '11 at 5:23

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .