Win 10 Pro x64, Z87 Chipset
4x2TB + a 64GB chunk of an intel 530 SSD for cache (rest of ssd unused), maximised mode (with UPS)
I have pretty much the same issue, before windows 10 the ssd cache was lightning fast. Now its awful, By running crystal disk mark i can see read speeds are very fast, but writes are around 20MB/s, used to hit 400-500 sequential in a test.
I have version 188.8.131.522, disabling windows write caching also doesnt seem to allow RST to manage the write caching.
Anyone else? not much online that gives any way of resolving, one outdate post i found from intel saying at the time 10 wasnt supported but nothing i can find since.
There are some reports of slow performance with the latest Intel® Rapid Storage version 14.8
At this stage, I recommend waiting for newer versions of the Intel® Rapid Storage.