[kwlug-disc] USB 2.0 vs. 3.0 on Linux

[William Park]

On Mon, Sep 22, 2014 at 06:49:36PM -0400, Khalid Baheyeldin wrote:
> So, I got two USB disks that support USB 3.0 speeds, and ran some times.
> 
> On an older machine that has only USB 2.0 ports, the speeds is as follows:
> 18.9 MB/s to 19.6 MB/s.
> 
> On a machine that has USB 3.0 ports, with both disks connected to the blue
> ports, and Ubuntu Server 12.04, the speed was only 59 MB/s.
> 
> >From what I read, real tests on USB 3.0 (ignoring the nominal speeds)
> should be 10X as fast as USB 2.0, which should be 200 MB/s at least.
> 
> So, is it because these are portable disks and the spindle is 5400 RPM? Or
> is it a bottleneck somewhere else?

- What kind of test?
- Sequential, random?
- DC or USB powered?
- Intel, AMD? -- Intel 3Gbps chipset is better than AMD 6Gbps.  You see
  the difference under heavy load, like 4 VMs in Hyper-V as I'm doing
  now.
-- 
William

> 
> Lori?
> 
> -- 
> Khalid M. Baheyeldin
> 2bits.com, Inc.
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