Slow USB 3 transfer?

[kyrcy]

I see no real difference between transfer rates of usb 2 and usb 3 external hard disks (of similar specifications) connected to an ASUS P8Z77-M motherboard. Transfer rates start around 100mb/s, but drop quickly to around 30-40mb/s. I have all drivers installed and flashed latest bios. ASUS support has not been helpful. Any suggestions?

[aedipuss]

are you mixing up your b and B? b is bits and B is Bytes. if you meant "B" those numbers are in the ballpark for consumer hard drives using usb 3

[Theodor]

Intel usb chipset drivers are not compatible with every external hd enclosures...
Same problem with the asrock mobo....same problem over here...

[kyrcy]

I bought a pci express usb 3.0 expansion card (NEC chipset) to try. A Verbatim 3.5" 3TB External Drive works fine at a speed around 100MB/s, but a Toshiba 2.5" 500MB External Drive does not work (when connected the drive sounds like continuously trying to spin but failing). Any idea what might be the problem?

[hech54]

I have one of those portable external HDD reader devices that connects HDD to your computer via USB....and it only works on ONE of my six USB ports. I still have yet to figure out why. I doubt you will solve your problem decisively.

[hello_hello]

I bought a pci express usb 3.0 expansion card (NEC chipset) to try.

I have one of those. It gave me a lot of problems initially. Often it'd only connect at USB2 speed (Windows would pop up with a "this device can perform faster" message.... or something to that effect) or it'd keep disconnecting. Then one day I disabled over-clocking and the problem went away, which seemed kind of odd.
Anyway.... after a bit of experimenting I discovered I could overclock and fix the problem too by manually setting the PCI BUS speed in the BIOS (100Hz, I think), instead of leaving it on "Auto". Seems the card is rather fussy about the PCI bus speed. Even if you're not overclocking, you could still try setting it manually if possible.

Just something to try.....
I've pretty much only used mine with one USB3 hard drive dock so I don't know if it would solve the problem for every USB3 device, but now the card is "stable" it's only marginally slower than SATA. It's definitely much, much, much faster than USB2.

http://en.wikipedia.org/wiki/USB_3.0#Speed_issues

[vhelp]

may i ask what speed tester are you guys using ?

i have a pci-e usb3 card that i've been using for a year now, and connected to WD external usb3 1tb drives. i assume they are at the 3x speed. but i'd like to be sure. thank you.

[hello_hello]

I just tried a "how fast can I transfer files" speed tester.

A 7GB MKV, internal drive to external drive via USB3, 1 minute, 20 seconds.
Same file via USB2, about 4 minutes, 30 seconds.

[DarrellS]

HD Tune Pro is a good program. They have a free trial...

http://www.hdtune.com/

[vhelp]

is there anything much smaller and not a suite ? i would write something myself if i knew exactly what i needed to get the correct results.

[aedipuss]

you could try crystal disc mark. http://crystalmark.info/download/index-e.html#CrystalDiskMark
get crystaldiskmark 3.02 portable in a zip. it's under 1mb.

[nic2k4]

... a Toshiba 2.5" 500MB External Drive does not work (when connected the drive sounds like continuously trying to spin but failing). Any idea what might be the problem?

2.5" drives get their power from the USB port. The problem you describe is caused by the port not supplying enough power to spin-up the drive. Easiest solution is to get a USB Y cable from ebay.

...and it only works on ONE of my six USB ports. I still have yet to figure out why.

Some motherboards have ports that can supply extra power. On my Gigabyte board, the rear ports can supply 3 Amps instead of the standard 0.5 A.

As for the maximum transfer speed issue, it is dependent on the drive itself. USB3 Flash drives can easily sustain 100 Mbps, but mechanical drives are still limited to much less than that (think around 40 Mbps sustained); it's a physics thing. Burst speeds are a different story; they can be much higher, but the buffer size will limit how long that speed can be sustained.

[hello_hello]

As for the maximum transfer speed issue, it is dependent on the drive itself. USB3 Flash drives can easily sustain 100 Mbps, but mechanical drives are still limited to much less than that (think around 40 Mbps sustained); it's a physics thing. Burst speeds are a different story; they can be much higher, but the buffer size will limit how long that speed can be sustained.

Well unless my math is bad I averaged about 90MB/s when transferring a 7GB file to test my transfer speed over USB3.
I think the last time I benchmarked a mechanical drive it started at around 110MB/s sustained at the beginning of the drive and was down to something like 50MB/s by the end of it.
Of course that's reading/writing a large, unfragmented file. When reading/writing a bunch of small files spread over the disc then seek times etc come into it and things can be a fair bit slower.