Why does my evo 850 say it's 5762 MB/s (ram cache drive detected)

[RealBboy360]

So with as ssd, I'm getting very high speeds, but another test says it's working as a ram cache drive, so that's probably why. I just got a new intel skylake and asus z170-ar mb.

Here's a comparison between 2 drives on the system, 1 samsung m.2 nm951 the other the evo.
http://i.imgur.com/l0xZfhs.png

What exactly is the ram cache drive effect and does that make it better than my m.2 drive?
I've noticed my visual studio times are about the same.

Here's the other thread I'm coming from. I have a pick a drive to use as my boot drive and I'm trying to decide.
http://www.tomshardware.com/answers/id-2765600/moved-amd-8150fx-intel-6600k-boot-drive-works.html

 

[geofelt]

I think you have enabled rapid mode on the 850.
Cache does well if you find what you need in cache.

From your pics, it looks to me like the M.2 is the better boot drive.
The random access read time is marginally faster, and that is what the os needs most.

But, if you are running apps that use drives as work space, then I think the more effective drive for that would be the m.2 and use the 850 evo as the boot drive.

 

[neieus]

That looks like what happens when you enable rapid mode on the Samsung. It will a portion of your ram for cache for the drive.