I just noticed it on my M17x-R4 with a clean install of Windows 8 Pro. Mine says 52.9 seconds right now-don't know what that means, as it sure takes less time to boot than that!
I did but an aftermarket Crucial M4 SSD in my system, but I do NOT have any expresscache stuff installed, nor any drivers at all for it. Very few system specific drivers that weren't built in to Windows (basically just Dell/Alienware's software to enable some of the function keys, plus Creative Lab's drivers, plus Nvidia's drivers).
Oh, also my system can boot with either UEFI or an emulated BIOS mode, the latter of which is what I use. Maybe whatever it is doesn't work if you're in UEFI mode, or-Samsung's UEFI firmware is known to be buggy, and maybe whatever this is doesn't work right with it.
I would assume it's an OS feature.