Question how many have maxed usb 2.o or 3.0 speeds with any peripheral?

[Rocketman122]

I have never seen more then 50% speeds listed by usb org.
using the best memory card reader and even using xqd or uhsII sd cards. never more then 50% usb 2 or 3
ive used the asus rog striker II mobo with q6600 years ago when it came out and have never seen more then 50% of the usb listed speeds

 

[sdifox]

Bandwidth cited refers to maximum capacity. You should never have a device take up the whole pipe.

 

[Rocketman122]

not what I asked

 

[Insert_Nickname]

I have. I can get 42MB/s out of USB 2.0 and 450MB/s* out of USB 3.0. I haven't managed yet to saturate 10Gbit USB 3.1, mostly because of the simple fact that I don't have an external device fast enough yet. Then there is the SATA3 bottleneck to consider (550-560MB/s).

There are a couple of things to mind in this however.

First of all you need a device that can actually read and write as fast as the theoretical speeds. In practice this means an external SSD with UASP support. UASP support is very important if you're chasing maximum speeds. BOT just can't keep up. It also improves random R/W by a tremendous amount, but runs out of steam at about QD4.

In practice an external 10Gbit USB 3.1 drive with UASP is effectively indistinguishable from an internal drive. Which is very, very useful for mobile. Where you can't always just add another internal drive.

For USB 2.0 this relates to the bus being half-duplex. This just means you can only send and receive in one direction at a time. Then there is encoding. USB 2 uses 8/10bit encoding, so you'll only get 80% of theoretical bandwidth through no matter what else.

USB 3.x uses 128/130bit encoding, and is full-duplex. It's superior in every way to USB 2.0.

*highest ever was 456.4MB/s, but that was a fluke I couldn't repeat.

 

[sdifox]

not what I asked

It is exaclty what you are not understanding. The max throughput is for the whole chain of serial devices. The bus is always designed to handle more than what a single device can pump out.

 

[Rocketman122]

I have. I can get 42MB/s out of USB 2.0 and 450MB/s* out of USB 3.0. I haven't managed yet to saturate 10Gbit USB 3.1, mostly because of the simple fact that I don't have an external device fast enough yet. Then there is the SATA3 bottleneck to consider (550-560MB/s).

There are a couple of things to mind in this however.

First of all you need a device that can actually read and write as fast as the theoretical speeds. In practice this means an external SSD with UASP support. UASP support is very important if you're chasing maximum speeds. BOT just can't keep up. It also improves random R/W by a tremendous amount, but runs out of steam at about QD4.

In practice an external 10Gbit USB 3.1 drive with UASP is effectively indistinguishable from an internal drive. Which is very, very useful for mobile. Where you can't always just add another internal drive.

For USB 2.0 this relates to the bus being half-duplex. This just means you can only send and receive in one direction at a time. Then there is encoding. USB 2 uses 8/10bit encoding, so you'll only get 80% of theoretical bandwidth through no matter what else.

USB 3.x uses 128/130bit encoding, and is full-duplex. It's superior in every way to USB 2.0.

*highest ever was 456.4MB/s, but that was a fluke I couldn't repeat.

what products are you using?

 

[Insert_Nickname]

what products are you using?

A simple external USB3-to-SATA3 enclosure with a 2.5" SSD in it. With UASP support. That's it really.

The controller is the bog standard integrated 10Gbit USB 3.1 AMD uses in their chipsets. Other then that, I do have an extra PCIe VIA VT805 controller in the system, but due to cable length to the front facing ports it'll "only" do 410'ish MB/s.

 

[Rocketman122]

I just ordered a an ssd enclosure to use with my 840EVO. I want to see if I can get very high speeds.