On Mon, Dec 15, 2014, at 11:17 PM, Dan Egli wrote: > Does anyone know how fast of a NIC can be hooked into a USB 3.0 port? > Specifically, I'm wondering if there's a 10GbE USB adapter for sale > that's > Linux compatible (you know that while most are, a few aren't or aren't > well > supported).
i haven't heard of anyone making a 10gbe usb adapter. doesn't mean they don't exist but i'd be surprised if there is one. usb3 has a max throughput of 5gbps so one wouldn't be able to max out the link speed of a 10gbe interface. that itself shouldn't say a whole lot though since there are a number of gigabit ethernet usb2 adapters even though usb2 can only do 480mbps. the bigger reason is cost. usb devices are usually cost sensitive devices and i can't think of any 10gbe controller that is under $100 just for the chip. even the most recent intel 10gbe controller (which is pcie) is listed at $117 for the controller. you would still need to add a phy and other supporting components. there are also power requirements that would get in the way. iirc, doing 10gbe over cat6 uses over 10 watts of power and i think usb3 can only do about half that will also transferring data. > I've got a potential project here, but the machine won't have any free > PCIe > slots, so I'm wondering if there's a way to hook a 10GbE NIC to a USB 3.0 > port and get reasonable speeds? The goal is to have a network with near > SATA speeds that PXE boots all workstations (current plan is for eight, > but > more could be added in the future). Any recommendations are most welcome! > I > can't use the PCIe slot that will exist on the Motherboard because it > will > be filled already with a different card. > i'd give it a try with just a gigabit interface first to see if that is sufficient. i did an experiment a couple years ago where i booted a windows machine off of an iscsi target connected over gigabit ethernet. loading games and regular desktop usage was almost as good as if the hard drive was connected to the local system. most hard drives can't push much more than a gigabit of traffic anyways. ssds can go faster but the big improvement that ssds give desktops is the random i/o improvements. even some modern ssds can't read random i/o at a gigabit. the speed limitation of a gigabit interface would be noticeable if someone decided to transfer large files regularly or during some benchmarking. so give it a try with gigabit. you probably will want to put a 10gbe network adapter in the system holding the storage. mike /* PLUG: http://plug.org, #utah on irc.freenode.net Unsubscribe: http://plug.org/mailman/options/plug Don't fear the penguin. */
