Slow write speeds to internal SATA HDD (~1-2MB/s)

[Devinology]

I have an internal SATA HDD in a new build that has very slow write speeds but normal read speeds when transferring data. I have tested it in HDtune and the outputs are normal. When transferring files FROM the HDD to other drives (internal m.2 SSD or USB drives) the transfers go at decent speeds. When transferring TO the HDD from the same sources, the speed crawls at 1-2 MB/s. Sometimes it starts out a little faster, although far below what it should, and then quickly drops to the 1-2 MB/s speed. I get this speed with any file sizes, either many small or one large.

The drive is a 3TB WD 3.5 inch drive I ripped out of an external casing, so I bought it as an external USB drive. It is SATA III 6GB/s and 5400RPM. I did this because I put an SSD in the computer for the OS, programs, and games, and I don't need a great HDD in it. I have a ton of external USB drives so I figured I may as well use one for this instead of buying a new HDD to put into it. I don't need great performance out of it as I don't run anything off of it, but I should be able to back things up onto it faster than this.

The drive is connected to one of the SATA controllers on the motherboard with a SATA cable that I know is functional. HDtune puts it at about 150MB/s write capability. I should be able to get at least 50-70 MB/s writes out of it. The drive passes SMART tests and other HDD tests perfectly.

Anybody have any idea what's going on?

PC stats:

Windows 7 ultimate x64 fully updated.
BIOS updated to F20 firmware. Mostly default BIOS settings (except for CPU OC, and RAM XMP mode).
Fully updated motherboard using official Gigabyte drivers for the board.

Gigabyte GA-Z170X-Gaming 5 (rev. 1.1)
Samsung 850 evo m.2 250GB
WD 3TB 5400rpm SATA III 6Gb/s
G.Skill Ripjaw V 16GB 3200MHz
Intel i5 6600K OC to 4500MHz
Geforce GTX 1070 Strix OC 8GB
CM Hyper 212 EVO (with an extra fan attached)
Bitfenix Shinobi ATX case with 6 120mm case fans (3 in, 3 out)
Topower 650W PS

 

[rhysiam]

What happens if you copy a single large file? I have seen 5400rpm drives slow to a crawl when backing up loads of tiny files because their IOPS are so terrible, and that becomes the issue rather than raw throughput.

 

[strelniksergey]

I have the same trouble.

Did you find the fix?

 

[The Paladin]

transfer rates and speed of writing have to be taken in account,. a 1TB 7200 RPM Black WD transfers at 160MB/s that random write/read, and a lot slower on 4Kib files. but when copying in windows the speed never gets that high anmyways, and that is normal.

run Crystal Disk Mark and see what I am talking about. as for your 5400rpm drive, the speed of transfer rate will be slower.

what is the model of your WD 3TB I am curious what buffer size they have on that ex-usb-external drive