2 x 2.5Gbe to USB teaming test request

[ForTheHoard]

Hello,

I read in this site about the 5gbe to usb adapers, and that they actually top at ~ 3.5Gbps. Since I cannot contact the staff of that site, I post the specifics of my request here:

2 systems with win7 enviroment (skip the whys)
2 x 2.5Gbe to usb 3.0 (or 3.1, whatever is the 5Gbps version), realtek based, on each system (total 4)
direct connection (no switch)
realtek's teaming driver (virtual NIC)

Is it going to work and achieve 5Gbps?

 

[BoredSysadmin]

A) you'll need to configure nic teaming (lacp) on the switch - and switch needs to be able to support this feature
b) assuming you do everything correctly, you will achieve a total theoretical thruput of 5gbps, but max bandwidth speed per session will still remain 2.5gbs - like a single large file copy, but two file copy processes together SHOULD come closer to 5gbps.

 

[ForTheHoard]

realtek has a driver for this, at least it works with 1gbps ethernet as seen in other forums (load-balancing 2 NICs), but I dont know if its going to work with 2.5g. What you describe is link aggregation; I am talking about NIC teaming which creates a virtual adapter with the combined speeds of NICs.

Also, it's going to be point-to-point. 2 systems, no switch.

 

[BoredSysadmin]

link aggregation=nic teaming. Both create a virtual adapter that shows max combined speed as nominal speed.
I am not 100% sure if this config could be used directly between two pcs without a switch. sounds like an interesting experiment.

 

[Drewy]

In my experience you won’t get any advantage to this setup between 2 devices. Regardless of the nics used (and many usb adaptor drivers don’t support teaming at all), teaming only works to increase available bandwidth when it’s a one to many connection I.e. a server with teamed nics that is connected to by many client devices.

 

[ForTheHoard]

I have no experience when it comes to aggregation/teaming, and I want to make a custom nas system and plug it directly with my main system, that's why I asked here. Reading through internet gave me the impression that teaming is NOT aggregation; and yes I know that with aggregation you don't do "ethernet RAID", but you know better.
I hope that the staff here (or any member of this forum) tha have access to adapters can do the test!

#make-it-happen!
#Just-Do-It™!

 

[ForTheHoard]

Bump and one side question to this: what latency the usb-to-ethernet add (point to point, no switch, 2 adapters total)?

 

[LodeRunner]

Bump and one side question to this: what latency the usb-to-ethernet add (point to point, no switch, 2 adapters total)?

Depends entirely on how busy the USB controller is and the DPC latency of your motherboard. Switches are generally adding a handful of microseconds, very rarely enough to show up in a ping test. Really fast switches are in the nanosecond ranges. Crummy home office switches might add a couple milliseconds.

I have no direct experience with USB NICs beyond those built into various USB docking stations, and I was more focused on making the damn things work properly (DisplayLink is garbage) than doing latency tests on the NICs. I was unable to find any good answers on Google about USB NIC latency. As USB is poll based instead of interrupt based, you may see some over all speed loss at the top end.

 

[ForTheHoard]

My dpc is at ~450μs. Also dont forget the USB polling rate override (at least in windows XP).
How does a USB keyboard work? - YouTube
this shows that fast usb keyboards have not too much difference than PS/2 in latency (fast versions, not common desktop version).

 

[hceuterpe]

I've done some decent amount of setup to get increased speeds with multi-NIC setups albeit via 10GbE. The highest achievements have been with RDMA support with NICs capable and I get nearly 100% of the max (20Gbs) in single file transfer tests.
The key to aggregating ports among the various options (RDMA, LACP, multi sigh RSS, multiple ports without any enhancements), even in single file transfers is actually more critical with the protocol used to transfer. The various options will get you closer to that 100% max of the aggregate bandwidth. If you have Windows in the mix, the easiest is SMB and using either SMB Direct (with RDMA capable NICs) or SMB multichannel. You won't see RDMA with USB Ethernet adapters so either RSS or LACP is your best bet. Recent versions of samba as SMB server also support smb multichannel pretty well one.

As for the USB adapters, you need to make sure they are connected such that they aren't sharing the same USB bus. If they are, they end up competing against each other.