Usb 3.0 · DIGIT-ARC

G

Hi Guys,

I understand that to use USB 3.0 super speed flash drives i need usb 3.0 port on motherboard and driver supporting it (win7)

The specs for USB 3.0 says

USB.org - SuperSpeed USB

SuperSpeed USB brings significant performance enhancements to the ubiquitous USB standard, while remaining compatible with the billions of USB enabled devices currently deployed in the market. SuperSpeed USB will deliver 10x the data transfer rate of Hi-Speed USB, as well as improved power efficiency.
SuperSpeed USB has a 5 Gbps signaling rate offering 10x performance increase over Hi-Speed USB.
SuperSpeed USB is a Sync-N-Go technology that minimizes user wait-time.
SuperSpeed USB will provide Optimized Power Efficiency.No device polling and lower active and idle power requirements.
SuperSpeed USB is backwards compatible with USB 2.0. Devices interoperate with USB 2.0 platforms. Hosts support USB 2.0 legacy devices.

But the current devices for example Flash Voyager® GT USB 3.0 64GB USB Flash Drive specs says-
*www.corsair.com/media/catalog/product/cache/1/small_image/165x/9df78eab33525d08d6e5fb8d27136e95/f/l/flashvoyagergt3_hero_2.png

*www.corsair.com/usb-drive/flash-voyager-gt.html
•Interface: USB 3.0
•Max Sequential Read/Write (using ATTO Disk Benchmark): 135 MB/s sequential read — 83 MB/s sequential write (USB 3.0)
•Unformatted Capacity: 64 GB

Another one-
*www9.pcmag.com/media/images/323268-kingston-datatraveler-ultimate-3-0-32gb.jpg?thumb=y

The Kingston DataTraveler Ultimate 3.0 Generation 2 (32GB) features USB 3.0 technology, with potential data transfer rates of 80MB/sec (read) and 60MB/sec (write)—more than twice the speeds offered by USB 2.0.

*www.usb.org/kcompliance/view/view_item?item_key=310ac21bda0f4f964a451084abfbf1eecb8de20d&referring_url=/kcompliance

So why USB 3.0 transfer speeds are at 135 MB/S,60 -80MB/S .The spec say 5Mbps ~=625MB/S.

So is this because of EMI/Motherboard limitation? or Windows limitations or anything else?

see there are limitations for the hard disk read write speeds that can bottle neck the USB 3 speeds. So they shown the variation limit.

G

thatsashok said:
see there are limitations for the hard disk read write speeds that can bottle neck the USB 3 speeds. So they shown the variation limit.

oK.If HDD doesnt bottleneck speed.What else is the limiting factor?

W

usb is just a medium to transfer.the only limiting factor is devices at both ends.flash drives use cheap chips compared to costly ssd drives from ocz,corsair etc.ocz vertex 3 has 550MB/s maximum read throughput and 500MB/s write speed.if you have a laptop with such a drive & a same drive in a portable external enclosure then you will see these speeds when transferring files through usb 3 port.

One line- Theoritical is never real.

USB 2.0 theoritical speed = 480mbps ~ 60MB/s, ever seen that?

To supports full speed USB 3.0 specs, flash drive makers need more expensive memories, making the end price costly, hence they use slower memories to keep cost down.

I get max 12MBps speed write and 22-25MBps on pen drives in USB 2 ...soo at least would love to get 120MBps write speed and 200 MB read speed and that will be 10x the performance

first of all practical max speed is always less than theoritical speed....
second both hardware should support the max max speed otherwise the one with the lower speed decide the max speed...
so here its because of hardware in pendrive....

sujoyp said:
I get max 12MBps speed write and 22-25MBps on pen drives in USB 2 ...soo at least would love to get 120MBps write speed and 200 MB read speed and that will be 10x the performance

Till date, I have seen 27MB/s max in 2.0, and 100MB/s (peak,not avg) in 3.0. Though avg speeds in 3.0 are around 60-80MB/s. All are write speeds.

W

as of now you need fast ssd like ocz vertex 3 to get avg read/write speeds of ~400MB/s & above

G

I have sata hdd.Using amd fx 6100 Proci.Win7 64 bit.My asus motherboard support usb 3.0.So what transfer rate can i expect i i get usb 3 pen drive in any of above mentioned.

Is there any good free tool to benchmark pen drives n my port.

^60-100MB/s

W

most commonly available reasonably priced usb 3 pen drives have write speeds of ~60MB/s.for benchmarking use CrystalDiskMark:
Download Center - Crystal Dew World