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Discussion Starter · #1 ·
Hello there,
I've been reading up about the usb3 chipsets, and speeds that many motherboards can get with them. Currently we don't have much to tax them, with future ssds and video capture cards when they get more popular may actually use it's full bandwidth available.

I have noticed that for H55/P55 based boards, It is likely impossible to get it's full promised 5gb/s transfer potential rate. This is because it may be running in "half speed" mode, detailed here:
http://vr-zone.com/articles/gigabyte...ysis/8158.html
In short, it seems to be having the usb3 chipset on a pcie Gen1 bus, running slower.

I'm a bit annoyed at this, because I want to actually run a Intensity shuttle usb3 device (it captures hdmi, and will likely want the full bandwidth available).

I've noticed that also on that page, Gigabyte and Asus have come out with "Turbo" or "Super speed" options, which give you a genuine full usb3 busspeed, by sacrificing your gpu pcie lanes from 16x to 8x.

I guess my question is, could I do something similar on the itx boards (I have a gigabyte h55n-usb3), or set my gpu to run at 8x in some way to emulate this?
 

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USB 3.0 is 600MB/s; PCIe on H55/P55 is only 250MB/s, that's why some boards link 2xPCIe lanes to provide 500MB/s for the USB controller. You'll notice that this amount of bandwidth still isn't enough, but it's certainly closer to the max of USB 3.0

To wire the controller to faster PCIe lanes some boards tale those links from the CPU, but the motherboard must have this feature from the beginning, which your motherboard has. The only thing you need to do is not to install a graphics card:

http://www.xbitlabs.com/articles/mai...5n-usb3_6.html
 

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Discussion Starter · #3 ·
That's a great link Dragosmp, lots of specific info about the actual motherboard... bit worrying that it's speed is even lower than I thought too.

I was hoping that I would be able to somehow set the pcie card installed's speed to 8x, so I could emulate it (the usb3 bus) having the higher speed, but doesn't appear I can. Bugger.
 
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