So that's as close as I came to getting it to run under Win10 10074...Magician 4.6 says it's "enabled" but lacking something...but it definitely isn't enabled at all... I'm throwing in the towel on this one....Samsung needs to step up to the plate, here...
I had it running in 9926 when I upgraded from Win7, but magician would crash. I then tried to install version 4.5 after clean install and got BSODs. Version 4.6 installs without crashing, but it's missing RAPID & Optimize. Version 4.6 even has optimize turned off in Win8.1(which is for TRIM and was actually put there for Windows versions without trim support). I just hope that they fix RAPID so it can "see" Windows version# 10.xxx.xxx and stop looking for just 6.xxx.xxx, because RAPID is a real boost. I have compared it to some PCIe SSD stats, and my Samsung 840 Pro blows them away(only with RAPID turned on).
I have a brand new Samsung 850 Evo ( for $89? yes please!) sitting on the desk next to me waiting for Samsung to update the Magician software to recognize rapid mode in Win10 on the drive. Since the 850 Evo is not recognized by the 4.4 version, I cannot sneak up on rapid mode. I have to stick with my 840 Pro until then.
BTW, rapid mode takes a while to tune itself to your most used programs and it works very well after it does. I remember after a few weeks, I booted up and said to myself "dang, that was fast!" and then remembered that I had started up rapid mode a while back. So it is a noticeable improvement.
Rapid mode is not really all that important. You can use your 850 now, and it will perform great, and when the new magician software recognizes Windows 10, you just enable it for that extra boost.
Here's what my stats look like.
In real world performance (daily usage) Rapid Mode has little to no performance gains except for write speeds which don't really matter since on SSD's you're trying to limit as much writes to the drive as possible.
Source: A closer look at RAPID DRAM caching on the Samsung 840 EVO SSD - The Tech Report - Page 1
Unless you have like 16GB+ of memory installed and don't know what to do with the spare memory (RamDisk), I'd say enable Rapid Mode with 4GB cache since the newer version of Magician 4.6 allows for up to 4GB.
Otherwise wait for an upgrade to next gen SATA express to to see real performance gains and not through some fancy caching via software only good for benchmarks.
I'm really surprised Windows 10 doesn't have native SSD caching which would greatly speed up Windows for users who are on tight budget and want the best of both worlds (SSD's boot time/load time and storage space).
Nemix thanks for the report link.
EDIT: And thanks for posting in this thread, because, it reminded me I'll need to turn RAPID off anyhow, because Windows 10 will crash and burn if I leave it on, when it installs.