Switching parts from one case to another

Hello everybody! It's my first post here and I wanna start off by saying I have mostly no idea what I'm doing or the terminology so bear with me please.

I have an Alienware X51 R2 with an AMD Radeon R9 280X. The case and PSU just wasn't good enought to keep up with the R9. So I bought a new case, the Corsair Obsidian Series 650D. I hadn't realized at the time, but it's quite big. My question is, will I be able to put all the stuff in without problems? I assume there will be enough space, but might there be any other problems. Also, I bought a Corsair CX600M PSU, will it be compatible with the alienware's motherboard? Because the X51 uses a laptop style PSU.

That's pretty much it, thanks in advance!

Yep, it'll all be fine. Looks like the Alienware uses a mini-ITX. It'll look so tiny haha

Lol, yeah, that's gonna look tiny, but should work fine. Since you seem inexperienced, I'll just toss out a reminder not to forget standoffs. I've seen more than a few people transplanting motherboards forget them. Have fun!

Thanks! But what about the laptop style PSU that was on the X51? Will the motherboard have any problems adapting from that one to the new one?

The CX600 will work fine. Uses the same connections.

Your Alienware probably has some kind of PSU board/module that takes that external power block and basically has all the connections a standard PSU has. So connection wise, it shouldn't be any different than the CX600 (well, the module probably has fewer connections, but otherwise). It'll work fine.

650D and an itx board, oh dear..... There wont be any compatibility problems, just a whole heap of empty space in the case. Something cheap like a Coolermaster Elite 130 would have sufficed.