r0ach, I find your first post inconsistent with my findings.
Originally Posted by r0ach
Most or all high end motherboards now only include a single transaction translator on USB hubs. This means that your mouse, keyboard, and any other device that you plug into your PC must ALL operate at either USB 1.x or USB 2 speed to not run into issues.
Firstly, it's strange that you're implying there's only one usb hub per motherboard. There can be one TT per hub, but I think you'd be hard pressed to find a motherboard with only one hub. My generic lowest-end Z77 has two usb 2.0 hubs and one usb 3.0 hub. Seeing as these are provided by the Intel Z77 PCH, I'd think my findings are naturally relevant to all modern Intel motherboards, which accounts for the majority of PC motherboards in circulation. Both of the 2.0 hubs on my motherboard have one TT each, so I decided to test your theory.
With a usb 1.1 device plugged into a hub alongside several 2.0 peripherals and an external hard drive, both Windows Device Manager and USBlyzer reported each device working at their intended transfer rates, instead of downgrading to usb 1.1 speeds, as you claim. The 2.0 peripherals were Full Speed, the 1.1 device was Low Speed, and the external hard drive was High Speed. The hub indicated that it was working at High Speed. I ran a benchmark on the external hard drive, and its performance was in line with the maximum transfer rate of High Speed usb 2.0.
Next, I unplugged the 1.1 device from the PC, as well as several other 2.0 peripherals, restarted the PC, and plugged the external hard drive into the other, unpopulated 2.0 hub. The benchmark I ran thereafter showed identical
results. Moreover, Idle CPU usage of my 3570k as noted by Realtemp showed a 0.0% difference with all these peripherals removed, the smallest increment being 0.1%. By the nature of usb, there is inherently more CPU usage than on PS/2, but in the real world, this seems to be a negligible concern.
Edit: I should note that I'm aware of the existence of third party USB hubs and controllers, but these would only exist on some motherboards, and only as an accessory to the already available Intel ones which use "Rate Matching Hubs", as seen for example in the following pdf:
If you're worried about performance, you should simply use only Intel USB ports, which to be honest, goes without saying. Third-party peripherals on motherboards seem to cause performance or other issues, almost without fail. Realtek vs. Intel on-board ethernet, Intel vs. third-party SATA, Intel vs. third-party PCIe slots, and so on.Edited by dukeReinhardt - 12/10/14 at 3:42am