@pmags: which windows version, only for "the records" ..
@leandoichi: could it be windows 10 related ? Did you try with 7 ?
@both:
Are your systems optimized for audio or just a plain Windows installation ?
Did you disable hardware in your BIOS which you do not use ? Did you disable sound chip on your mainboard ?
Did you fine tune BIOS/Windows already for better audio processing (disable "energy saving" for CPU, etc).
Could it be that other drivers / programs on your system are blocking the CPU from processing audio "in time" ?
Did you do any research on this topic already with tools like LatencyMon ?
When I remember back when I had Focusrite LS 56 and an old MSI board it was the board itself which caused issues.
Without tuning BIOS / Windows you had very bad kernel timer latency values and nasty spikes (200-800+ µs).
With tuning I got it down to 80µs with spikes over 100 which brought at least stability, but not ideal results.
By pure occasion I upgraded to the "A" version of the same board (the successor which brought USB3 and Sata6).
With the same BIOS settings like on the old board and the same windows installation the values went down to 2µs at minimum and with averages of between 5 - 20 µs on a not loaded system.
What I want to say ... I suggest that you make a proper analysis of your systems.
I would regard it as relatively unlikely, that the RME drivers cause issues here.
Otherwise the forum would be full of people, telling about bad performance.
Actually the RME drivers are so well, that I am with the USB driver of i.e. the UFX not that far away from the results of a PCIe card like the RayDAT when looking at Cubase 8 Pro's display of input and output Latency. Example: both interfaces set to 64 ASIO buffers
RayDAT (PCIe!): Input Latency: 1,497ms, Output Latency: 2,245ms
UFX (USB2) : Input Latency: 2,063ms, Output Latency: 2,993ms
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13