Matthias
According to my other post, I have both cardbus and expresscard. I read that it came off as confusing and I apologize for that. I didn't intend to mislead anyone. Please feel free to edit and point the misleading parts or remove the post if it helps.
As for adding details on the W10 situation:
The cardbus used to sit in a PCI adapter with r5c475 chip (driver indicated R5C485). The Mobo is a Gigabyte Z97x SOC FORCE. W10 is a clean install but I did first upgrade from W8.1 which was itself an upgrade from 8.0. It seemed to be OK back then but I made few tests and quickly ran a clean install to start fresh.
Software is SAC, REAPER and BITWIG STUDIO, all running concurrently with few tracks (8-12) at 1X32 samples buffers. I do need multi client driver but don't use WDM at all.
I recently bought the expresscard to be rid of the bridge altogether, as I plan for heavier projects. I use some Vsti with either guitar or keyboard input and usually stick to the lowest latency at the expense of CPU load. The CPU is a pentium at 4.3 ghz with a bus at 100. Memory (2X8GB) runs at 1600 since I swapped to low voltage sticks but the previous sticks (4X4GB) were at 2400 and worked fine too, even shaving a few ns from overall memory latency. Power requirements is what motivated the move to DDR3L: the PC sits in a rack and goes on stage.
I can see little to add, except maybe repeat that the PCiE adapter looks transparent to Windows, as opposed to the PCI adapter which required its own driver (present in Windows 10). That seems key to me but I may be wrong. Also the PCi bridge on GA-z97x SOC is tied to a PCiE port (on PCH) that is exclusive of another one, connected to the CPU. That warrants some BIOS tweaking. Also, both Multiface or Digiface couldn't recover from sleep state, S3 or higher but were fine with S1.
Then I'm out of my depths and I couldn't explain how I had cardbus working on W10. I just sold it with the adapter, bundled with a Digiface and I won't be able to help investigate further with this machine. However, I have a second cardbus for a redundant system on W7. I plan to upgrade this old core2 duo tablet which has both cardbus and expresscard; I'll make sure to report of either success or failure when I get there. Thanks for pointing out that I definitely need to image the partition before switching.
Regards,
Roger.