Dear Intel support team,
I am still looking for an answer.
In the meantime we found some additional information:
"Some motherboards improperly implement centre-spread SSC clocking, which violates the USB 3.0 specification requirements. Centre-spread profiles are centered on the nominal frequency and are modulated above and below by equal amounts, for example +2500/-2500 ppm. Most USB 3.0 devices are not compatible with systems that improperly implement center-spread SSC. When consumers purchase host add-in cards and add them to a system that has a noncompliant system clock, they will be disappointed."
How did you realise the SSC on the DX79SI motherboard?
How can I disable the Spread spectrum Clocking? In case it is not possible, is this function available in an old bios version or with another tool?
The Intel(R) Desktop Board DX79SI is compliant with the USB 3.0 standards and there is no option to disable
Spread spectrum Clocking or has been or earlier BIOS versions.