although my issue is similar to the one in this thread:  , it wasn't fixed by downgrading the bios to 1.04, so I thought I'd post a new thread.
 
I have a new build with the following components:
z97 FTW (i recently RMA's a z87 for the z97 since we couldn't get the z87 to recognize the cpu)
i7-4790k
GSKILL F3-14900CL9D-8GBXL x 2
OCZ 700W PSU: ocz700MXSP
256GB Crucial SSD:  ct256m4ssd2 FW: 0609 x 1
evga  650Ti GPU (haven't received new GPU yet)
 
I am getting random freezes that are unrecoverable.  When this happens, I can still see the desktop but cannot move the mouse or type with the keyboard.  If a video was playing, the video will freeze and the audio will just be a continuous tone.  Although the lights on the ethernet port are still on, I cannot ping anything.
 
sometimes the freeze happens really quickly, other times, I don't see it for an hour or 2.
 
It freezes when I'm actively doing things and when I am not at the computer.
 
I am running windows 7 64bit, updated with all the latest patches.  I have also downloaded all of the latest drivers from evga for the motherboard.
 
What I have done to troubleshoot:
1.  memtest on each stick of ram, one at a time.  3 passes each.  no failures.
2.  ran the intel cpu test utility.  that passed.
3.  tried a single stick of ram in each slot.  still observed freezes.
4.  swapped mouse/keyboard.  no luck.
5.  ran with only integrated video (removed the nvidia card).  still froze.
6.  disconnected every other peripheral/connection other than psu, mobo, ram, HD.
7.  checked temps.  running a bit warm, but the temps never get past 50C at idle.
8.  swapped the ram out with some older (slower) ram.  still got a freeze.
 
The only thing that I haven't swapped yet is the HD, CPU (i only have this one), and the PSU.
 
Now, I did one more thing to test the system.  I booted the computer up using an ubuntu USB 3.0 drive.  I have now been running on that for over 7 hours without a freeze.  I'm typing this up using it!  So what does that mean?  is the windows install bad?  Did I get an incompatible driver?  is the ssd bad?
I guess my next step would be to try a different HD, and reinstall windows on that.  The firmware on my SSD is not the latest, so I could also upgrade them.
 
Otherwise, I welcome any suggestions.  It's really frustrating.  I've built quite a few of these, and this is the first one to give me hell.  (also, I'm not OC'ing anything yet)
 
 
Thanks!

i'll give that a shot tomorrow.  I have 2 more ssds that I could try as well.

I guess I could go pick one up today and try it out before I go swapping ssds around.  That would suck, but maybe it's not quite compatible or going out.  :(

Is there a firmware update for the ssd?  Have you tried a different sata cable and port to the drive?