I purchased a 256g 600p for my MSI z170 gaming m7 motherboard in December 2016. I have had the drive up and running on a windows 10 install along with several other drives, a crucial mx300 m.2, a crucial m4 2.5" and a pair of WD black spinners in raid1 with a 64G portion of the M4 SSD acting as a caching front end of the raid1. The issue I am having which I noticed when some windows updates were taking WAY too long, the 600p which is my OS drive seems to be having very slow writes. I verified this with CrystalDiskMark and AS SSD Benchmark. The reads are always "normal" sequential in the 1500MB/s area with the rest falling in line with other samples I saw on the web. The writes sometimes slow to a crawl and seem to make the system hang at times. Sometimes the write tests start off at 550MB/s and then slow to a crawl at under 10MB/s by the end of the test. But sometimes they just start slow too. I had one instance where it almost looked normal through the whole test - but 9 times out of 10 it will start fast and slow to a crawl quickly with reads being pretty normal. It's very weird.
I have done the following to try and fix this:
Moved my swap partition to the other m.2 ssd in the system (which is acting 100% normal, but it is SATA based m,2)
Updated RST to the latest version 15.5.something.1051
Updated all z170 chipset drivers to the latest
Updated my motherboard bios to version 1.H (which required all bios settings to be set default and then re-configured to recover the system. that was, uh, fun)
I have not updated the firmware to 109c yet. I usually update a drive firmware with the OS on it as a last measure.
I installed the Intel SSD Tool Kit 3.4.5 but I can't run any of the tests or optimizations because the "ok" button is not press-able (grey) and there's a message in red on all of the test tabs: "cannot run as a member of a raid array". I have my controller set in RAID mode because of my raid1 storage but the 600p is not in any kind of raid configuration. So I don't know how to fix that.
I did find this while searching for a solution:
I know superfetch is off and I am pretty sure I disabled indexing but I will need to check. The other things I was going to try was this:
Beyond that I am running out of ideas. Any and all help here would be appreciated.