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: Hard Drive Speed Rapidly Decreasing.

20 Dec 2012   #1

Windows 7 Ultimate x64
Hard Drive Speed Rapidly Decreasing.


I run my computer off an SSD.

But I have 2 Samsung 2TB drives for storage.

I regularly have to transfer filed from one 2TB drive to the other. Until not it has always been a fairly speedy process.

The problem I am having:

I am transferring a large file (5GBish) and for the first 5/10 seconds it transfers between 120 MB/sec - 150 MB/sec, but after that it suddenly starts slowing down, until about a minute later it's sitting at around 20 MB/sec.

I'm sure this never happened before? What is going on?

See pic for example:

My System SpecsSystem Spec
20 Dec 2012   #2

Ultimate 32bit

Maybe there are many files which is small enough to decrease your transfer rate .
My System SpecsSystem Spec
20 Dec 2012   #3

Windows 7 Ultimate x64

Is it just one file?
My System SpecsSystem Spec

27 Dec 2012   #4

Windows 7 Ultimate x64

Yeah, single 6-8GB files.
My System SpecsSystem Spec
27 Dec 2012   #5

Win 7 Pro 64-bit 7601

Assuming your hard drives are formatted with NTFS (standard), I'd say it's normal.

File transfers to NTFS drives are cached, they appear to go faster in copy-paste as the stuff is actually loaded to RAM while it is waiting to be written in the HDD, the speed of this is higher. For small files the trick can fool the user as the process says it has finished the copy well before it has actually written everything to disk. This is an issue for USB drives formatted with NTFS (mainly hard drives, flash drives and SD cards are formatted with FAT32 or exFAT), as it tricks the user into thinking he can disconnect the drive while it is still writing (causing data loss).

With big files, this kind of caching isn't particularly useful as the transfer speed is the same regardless, so the shown speed decreases until it eventually matches the actual transfer speed.
Around 20 MB/s is normal transfer speed for a HDD (the fact the files come from a SDD is irrelevant, the HDD cannot write faster than that anyway).

If you use third-party file transfer software like FastCopy, you will see actual file transfer speed since the beginning, again around 20 MB/s, as such performance-optimized programs cache only a few dozen MB at a time, and only if actually advantageous to do so (like when you are copying files inside the same hard drive).
My System SpecsSystem Spec

 Hard Drive Speed Rapidly Decreasing.

Thread Tools

Similar help and support threads
Thread Forum
Storage Space Rapidly Decreasing for no reason
Today I noticed my storage space, last I recall being 20GB out of the 464GB, was hovering around 100kb and changing infrequently. I havent downloaded anything since Monday. I deleted 15 gigs worth of games and then ran malwarebytes. It found around 20-30 trojans and 120-130 pups. It deleted them...
Performance & Maintenance
hard drive losing space rapidly (170gb over past week)
I was baffled to find my main drive with 80mb space left after freeing up 170gb of space last week. This has happened repeatedly, WinDirStat can't figure out what's taking up all the space, I've run disk cleanup, defragged and ran multiple different virus scans, all to no avail. Literally my entire...
Performance & Maintenance
Hard drive space decreasing rapidly
Hi there, My hard drive space is suddenly decreasing rapidly (30MB every few seconds), and I don't know what's causing it. It was 14 GB a couple of days ago. I've restarted my computer, and I've deleted some data, so it's just under 1 GB now (it got to a critical point earlier where it was at 96...
Performance & Maintenance
Hard disk space rapidly decreasing
Hello, Fours days ago i installed a game on my pc (Harry Potter and the deathly hallows 2) and after ending it i uninstalled it and that's when the problem started. I kept seeing this even after uninstall.... I have to to uninstall again and again but i just get this. The main problem...
General Discussion
Memory Decreasing Rapidly
Hello, well y was on my computer yesterday and i noticed my computer's memory is decreasing for no given reason, i checked it again today and noticed it decreased again. I'm really worry and what is happening i'm not sure if it's a virus that i have on my computer. I checked with my Antivirus...
Performance & Maintenance

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 08:55.
Twitter Facebook Google+