I've had this machine for a few years now, Intel 5520 chipset, 2 X Intel Xeon processors no overclock.
 
The PC hasn't really missed a beat until Nov 2nd when it has started to blue screen, general hardware error 124. The four address codes are the same apart from the second which changes, indicating an NMI error. The processor fans seem to modulate in speed just before a crash, and while we are using AdobeCC. Graphics card is a GigaByte GT740. 
 
I had a OCZ Vertex 128GB SSD which I imaged to a Samsung 256GB EVO SSD. I've replaced the PSU, taken the heat sinks off the processors and re applied thermal compound. I've swapped the graphics card with another, and tested all 48GB of system memory (Hiren BootCD memtest86).
I've checked all the correct drivers are installed with those listed on the EVGA site, and flashed the BIOS to the latest.
 
I'm running Windows7 64bit, with AdobeCC, AME, Photoshop etc. I use the PC for graphic design and video rendering. Does any clever person out there have any good ideas, or anything else I might try. There are no beeps when the motherboard boots, and machine seems to run fine in safe mode, and when running DOS based tests.
 
Many thanks in advance
Steve

I know you've tested the memory but try 1 stick at a time

Bsod 124 points to a a cpu problem. Try increasing the vcore on the cpu's to see if it helps get rid of the bsod.

Thanks guys, I'll try both and report back!