USB 3.0 hub throughput

I'm considering buying a Lenovo X1 Carbon (1 USB 2.0 port, 1 USB 3.0 port, 1 DisplayPort) as my primary machine. However, I plan on having a widescreen monitor, keyboard, mouse, and an Ethernet cable hooked up to this machine.

Since there's no dock connector on the X1C, I was debating buying this 3.0 dock from Lenovo:

Lenovo USB 3.0 Dock | 0A33970 | Lenovo | (US)

Will connecting this hub to the one USB 3.0 hub give me enough USB bandwidth to hook up the following:
1. USB keyboard
2. USB wireless mouse
3. Ethernet (gigabit port on this hub)
4. DAC

As far as I can find, USB 3.0 has a bandwidth of 5Gbps and Gigabit Ethernet can go up to 1Gbps. Would 4 Gbps be enough to power the DAC (converting FLAC), USB keyboard, and USB mouse? I figure, like with power supplies, this is some sort of math problem.

Any help would be great! Thanks!

 

Personally, the max throughput i personally experienced on USB3.0 is ~1.6Gbps of actual throughput. That however should be enough for ethernet, dac, keyboard and mouse.

 

What hub were you using?

 

It wasn't a hub, plugged straight to a USB port and benchmarked with a SSD, a good hub shouldn't give you a loss in performance though and given your usage 600Mbps should be enough for DAC, mouse and Keyboard. Note that the 1.6Gbps is useful data being transferred after accounting for overhead. Final performance will depend on your drivers and USB controller, Intel's USB3.0 controller will likely be faster on ivy bridge than the third party controller on my P8P67 Pro motherboard.

 

Yeah, I guess this whole question is heavily dependent on the performance of the USB 3.0 port on the X1C, right?

I would hope Lenovo's new USB 3.0 hub would be pretty decent quality, too; but what do I know...

 

I can't help you with the hub, but one USB 3.0 port should be enough for those devices if the hub is capable to deliver, just don't expect to get the full 5Gbps bandwidth. I'd expect Lenovo's hub to be rather decent too and i'd be surprised if you were using the full 1Gbps LAN bandwidth all the time either meaning that you'll have room to maneuver should you need it.

 

Intel has been known to have sorta shotty USB drivers... I can attest to mine being unstable with ivy bridge the first 2 attempts installing the driver. Once it settles in correctly it does work well, though.

 

How does one measure the true bandwidth needed by devices and LAN and provided by a hub? Any ideas?

 

If you wanted to measure the bandwidth provided by any type of port, just plug in something that you know can use more bandwidth than the port and then test it. It'S harder to measure the bandwidth required by a device unless there is a monitoring program for that.

LAN at 1Gbps means that is the maximum bandwidth provided by the interface including overhead (data that is required for the devices to communicate with each other and needed for the user data to be transfered correctly, but not part of data transfered to and by the user) so assume that if you fully use the LAN, you will use 1Gbps. For the other devices, keyboard and mouse, those don't require a lot of bandwidth, you can have those two plugged into a USB2.0 hub without any problems.

Also, if all three devices, dac and user peripherals can do just fine on a single USB2.0 hub then those + LAN on USB 3.0 will do just fine as well.

I measured the bandwidth available for user data on my USB3.0 ports with a SSD that can go at ~500MB/s on SATA 3 so when i hit 200MB/s and it stayed there, i knew i had hit the limit afforded by the USB3.0 controller on my motherboard.

When i wanted to measure my network bandwidth LAN to WAN, i transferred a file a few GB in size and timed it, i noticed as a result that Windows does a good job at indicating the transfer speed in MB/s.

For devices like keyboard and mice it's harder since you'd need something that monitors data coming to and from the USB controller (i really don't know if such a thing exists).

It's likely that you have a USB 2.0 hub, if you do, like i said, plug in your mouse, keyboard and DAC, play your music and see fi there is any lag in playback, keyboard or mouse input. A single USB2.0 port has a maximum of 480Mbps including overhead so if the hub does the job, then 1Gbps LAN added to that will make a requirement of 1.48Gbps (and that includes overhead on USB2.0 so in reality you'll need less than that actual throughput) which a single USB3.0 port can handle.

To be honest, i only ran once in a bottleneck on USB2.0 and that was when i was using a dac and at the same time backing data a couple of GB in size to an external HDD plugged on the same USB2.0 hub.

 

Makes sense to me. Thanks for the reply!

I don't yet own a DAC so I don't really know how well it would run over USB 2.0 or USB 3.0. I may never buy one but I wanted to plan for the most stressing scenario when buying hardware components. I'll probably turn to an audio forum for DAC-specific advice.

 

Alright, in any case your DAC will likely be USB2.0 which means that you'll be fine. I haven't run into a USB3.0 DAC yet.

Throughput problems and questions are never easy unless it's for a specific case.