actually the numbers aren't shabby, and actually "smokes, cooks and burns" compared to a Sata SSD, I'm benching 1088 MB/s read and 833 MB/s write which is a little lower than specs for it, but in day to day operations, i see boot times of 5 secs after POST, and heavy programs like photoshop, quickbook, UPS worldship open in 1/3rd the time they did loading from a samsung 840 evo. The sm951 is supposed to be about 25-30% faster (the AHCI version) but i doubt i'd see or feel the difference from my xp941
but you might want to review the forums, whether the xp941 or the sm951, there are issues installing windows on the xp941 as a boot drive - it took me 18+ hours reviewing various websites for the solution, but the solution was a constantly changing set of BIOS settings as the mobo mfgrs updated their BIOS releases.
Windows 7 is a little harder to load than windows 8 but the best set of instructions for my asus Z97M-Plus were on the asus forums at
https://vip.asus.com/forum/view.aspx?id=20130111005429811&board_id=1&model=P8Z77-V+LX&page=1&SLanguage=en-us
in spite of Hiker's instructions, i still installed windows via a bootable USB flash drive created with RUFUS (google for it) - main reason, it loaded windows in 6 minutes versus 45-55 minutes via DVD drive.
notes to save some headaches
1) make sure you're working with a retail copy of windows, not an OEM
2) be sure to wipe the flash drive and format as FAT32 (as the bios on your board should be UEFI
3) the xp941 will have to be wiped using diskpart as Hiker describes (DO NOT USE SAMSUNG'S SECURE ERASE OR PARTED MAGIC'S SECURE ERASE - it will turn the xp941 into an expensive bookmark, ie brick it)
4) be sure to partition the xp941 in disk management as "GPT" - that's because of the UEFI BIOS (again)
and be aware, as the xp941 is only sold as an "OEM" part, there's a limited warranty from the vendors. RamCIty is pretty decent offering a full warranty, but most are only offering a 30 day warranty.
The main issue with installing windows as a boot drive is the fact on both the xp941 and sm951, they lack "OPROM" or small boot files that tell the computer to load boot files from windows - that's the full extent of my knowledge on the affair. As they're sold as "OEM" to lenova, sony, dell etc, samsung assumes they'll configure them with whatever boot files they'll need.
I also ended up discovering a "fred flintstone" installation method i posted
http://www.tomshardware.co.uk/answers/id-2615594/installing-samsung-xp941-win-64x-boot-drive-fun.html
i discovered the above as i ran into the same headaches getting windows 7 installed the second time, and thought i'd try a shortcut - it did save some time re-installing the original programs i had installed after windows - total re-install or fresh install time takes me 11-12 hours with activating programs, setting settings, etc
if you go that route, and run into issues, pop in here