USB 3.0 Transfer speed dies at 25%

robjonaldo · 11 Jul 2017 at 21:11

Hi there.

Does anyone have any idea as to why my USB 3.0 drops off like this?

Ive disabled USB legacy in bios and enabled caching for this device in device manager but its made no difference. Also tried 3.0 port on back of mobo but same result.

My USB 2.0 gets a solid 22MB/s without this slowing down using the same usb port.

The pc is about 4 years old now but I have purchased a new usb stick today and I'm just pretty dismayed at the speed it seems to be getting due to this. Starts off fine then just dies...

windows file transfer

HD Tune

USB 2.0 in the same port

ED209 · 11 Jul 2017 at 21:15

Have you got any other USB 3 devices like HDDs or USB sticks to try? it could be a faulty USB stick but without another USB stick\HDD to test it maybe a bit hard to narrow down.

whats the make of the mobo and USB stick you bought?

screen shot of my USB 3 HDD - Seagate expansion drive

robjonaldo · 11 Jul 2017 at 21:18

Mobo is MSi Z68a-GD55-G3 and USB which I have just got today is a SanDisk Ultra 32GB

Plugging the USB 3.0 into another 2.0 port reads about 35 MB/s solid

lude1962 · 11 Jul 2017 at 21:30

what model sandisk is it?

lude1962 · 11 Jul 2017 at 21:38

how much use has the ocz 60gb had?

the hd tune results are probably accurate for the usb drive
sd ultra:with speeds up to 100MB/s
that speed isn't usually sustainable, write speeds are a lot lower

robjonaldo · 11 Jul 2017 at 21:39

Flair ultra 150Mb/s
SDCZ73-032G-G46

robjonaldo · 11 Jul 2017 at 21:44

The SSD has had a lot of use yeah. The build remains unchanged from when it was put together. Specced by the people on this forum from my post in 2011.
My one hard drive has been replaced and is only a few months old

Disco_P · 12 Jul 2017 at 01:10

It's a lovely feature of the drive. It has about 1GB cache of super fast storage that can be written to at about 100MB/s and then the rest of it is slow flash that can only be written to at about 20MB/s.

My HDD has something similar which allows for nearly 500MB/s writes for the first 1.5GB then down to 100MB/s for the rest.

GWANGY · 13 Jul 2017 at 13:26

yOU MIGHT BE BUFFERING ALSO IN YOUR pc .. SAMSUNG RAPIDWRITE DOES THE SAME , IT TAKES 1,2,4 GB (MAX 25%) OF YOUR DRAM AND USES THAT AS A BUFFER, SO THAT IF YOUR FILE FITS IN THE BUFFER IT FINISHS ALMOST INSTANTLY. BUT DISCO P SOUNDS BETTER, LOOK UP "SSD SLC CACHE".