Windows 7 Forums
Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.

Windows 7: Dramatic slowdown copying two files at once

09 Feb 2016   #1

Windows 7 Ultimate x64
Dramatic slowdown copying two files at once

This is a problem I've had for several years now. I fully expect two file operations at a time to be slower than if run sequentially, but not this much slower. If I copy a file or group of files to (or from) my NAS I get a speed varying from over 100 megabytes per second down to 30. I can't explain why it sometimes goes at 30 instead of 100. If I launch a second operation while the first is still running, they both slow down so that the net speed is now 10 to 15 megabytes per sec. When one of the operations finishes the other does not resume at 100mb/s, it gradually increases (just averaging no doubt making it look like the speed increase is gradual) and tops out at around 10 to 30mb/s.

This behaviour has been consistent for several years and is a bit annoying. I can easily launch operations consecutively using various kludges like disk commander programs, the 'queue' option in WinRAR etc, but I wish I didn't have to. Also the random reduced speed on single file copy operations annoys me. Instead of taking a few tens of seconds to copy a file suddenly it takes a couple minutes for the same file.

The behaviour seems to occur between any of the drives in my system, from SATA hard drives to SATA2 SSD to the networked NAS. I can copy between distinct pairs of drives without a penalty, but if it's the same pair... bang... one tenth of the speed.

Only other thing I can think of that might be relevant... I also get 'kernel freezes' for a second or two if I perform big directory operations on the NAS. You usually only notice this if music is playing - there's a half-second or so pause in the music, even with VLC set to use a 5-second buffer. If you let the NAS RAID partition fill up then these pauses become irksome, like everything freezes for 30 seconds at a time. I never let it fill up these days.

The NAS is a Thecus N7700pro, SSD is a Samsung 830-series, SATA drives are mostly Seagates. Network card is "Realtek PCIe GBE Family adapter".

Motherboard is Gigabyte GA-EX58-UD4P, CPU is 6-core Intel i7 970 at 3.2GHz.

I suspect a dodgy driver for anything from mobo chipset to a disk drive or network card... no idea how to narrow it down. Also if this was 'normal' Windows 7 behaviour I would have expected to see more complaints using Google...

My System SpecsSystem Spec
11 Feb 2016   #2

Windows 7 Ultimate x64

Hrrrmmmph. Since I was looking at the issue I decided to Google and found a few irate individuals with similar issues over the years, usually having problems with 100mb NICs running at a few hundred kb/s speeds instead of close to the 10mb/s max.

Eventually spotted a few things
1. Add a DWORD registry entry DisableBandwidthThrottling, value 1 to
2. Went into Device Manager, NIC properties, Power Management tab and turned off "Allow the computer to turn off the device to save power"

After clicking OK to this, NIC and network shares etc went offline while it thought about it, then when it came back up I can suddenly copy two files using two Windows Explorer windows at around 49mb/s each (without rebooting).

Not sure which of the above two changes fixed it.
My System SpecsSystem Spec

 Dramatic slowdown copying two files at once

Thread Tools

Similar help and support threads
Thread Forum
Dramatic FPS drop when recording
This has only started happening recently, on games such as AssaulCube Reloaded, or Minecraft, or even CS 1.6 With minecraft I usually get 70-130 FPS when not recording, but then when I start recording with Fraps, it drops to 8-10 FPS. With AC Reloaded I usually get 90-140 FPS, but then when I...
Windows Journal freeze or slowdown with 2mb or larger files
Hello, I'm new here so apologies if this has been asked before. I've been having problems with windows journal when a note file reaches 2mb or more. I use an (older) tablet pc with a core duo CPU running Windows Home Edition and I wonder whether this may be the problem as upgrading my RAM to...
Dramatic download speed change
Hi. Before I begin let me tell everyone that my download speed is terrible, so please no laughing etc. lol. :P A few days ago my download speed increased dramatically. I was told by my ISP a few months ago that because of the old lines in my neighbourhood that the maximum speed I could reach was...
Network & Sharing
copying files to mydocs or program files
I tried doing this. Example.... game files/data from my XPdocs on C: to my win7 docs on D:.... couldnt do it, just gave me a chime, no dialogue box or anything. Also tried to move a file from my desktop to either mydocs or to program files folder, same thing. After that, even took ownership of...
General Discussion

Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 17:00.
Twitter Facebook Google+