hardware or software issue

I just got myself a new computer, (including a new motherboard and a new NVMe SSD.) The new ssd has windows and everything i need, but i would like to transfer the old ssd to the new motherboard. (and reformat it because i have already transferred all the important files and would like to just...

So my normal setup is: i5 4670k h81m-p33 Mobo 500w coolermaster power supply 8gb Ram 1Tb black edition HDD My issue: Rig works perfectly with a GTX 650 even with over clocking it through Afterburner, however (and here's where it gets fun) when i plug the Gtx 465 in, it boots fine and loads...

I have a question about case dimensions ... as I have never built a PC. When they list dimensions on PCpartpicker is it: W x L x D or L x W x D *(Its down in the left hand corner of the screen on most cases) Thanks!