On the Surface Studio that I received recently, the Intel RST is configured to use the full 128GB SSD as cache. See the following -
Unfortunately, when I disabled the cache drive and tried to re-enable it, it would not let me use the full SSD as cache drive (only up to 64GB)
Now I can only use half of my SSD as cache (see below) - this makes me nuts!
Please, Intel or Microsoft, I was really upset with this, I really need my system back into default to use the full 128 GB SSD as cache, like when it was shipped. Also, Intel should release the RST software update ASAP (whatever they have done with Microsoft in secret to enable 128GB caching).
(Sorry I was just upset because half of my SSD caching was gone and Intel definitely has the technology ready but the software simply artificially caps the caching limit to 64GB!)