These kinds of issues are why I always suggest people do fresh installs of operating systems, and not upgrades.

I used to do that, then I released how many pieces of software I have installed, and tweaked and adjusted to my preferences. Usually there is little benefit to an upgrade so I just leave as is (or use a rolling release Linux distro).

I get similar memory leaks with WindowServer on a brand new macbook pro. The damn process is eating 4gb of ram sometimes...

I did a fresh install from a seemingly healthy, semi-recent MBP and Yosemite's WindowServer seemed to begin a slow strangulation on my machine.

Solved it by buying a top-of-the-line machine, which I'm sure Apple is loving.

I discovered a weird interaction between f.lux and fullscreen gaming. They seemed to fight about which gamma etc to use.

It was nothing you could see, and other than a jerky in-game mouse you did not notice it. And after an hour of playing, dying cmd+tabbing out to Safari to surf while waiting for respawn, WindowServer core dumped, logging out all users in an instant.

This is fixed in 10.10.3. The jerky mouse pointer problem still remains. I don't use f.lux anymore.

Gotta be a hardware issue of some variety. I'm running Yosemite on a MBPro Retina mid-2012 with zero issues at all.

Hmmmm, possibly my slow-as-could-be hard drive. The SSD in my newer machine really does make a HUGE difference, to speak obviously ;)

I have the feeling my old machine is using a bit of VRAM when WindowServer starts getting too heavy.

Updating my iMac to Yosemite fried the graphics card. It seems Apple is putting form way ahead of function, and as a result stuffing too hot components into too small space (the same iMac has previously fried the screen and the HDD to death).

And way back in time, Apple had even factory-disabled my second NVIDIA card on my MBP because it had created heating issues in tests. So, I installed gfx, or something, to get it working. And then, predictably, major major heating issues.

And it was easily solved! Apparently Apple (the rumor is Jobs ordered this, but who knows) didn't want the fans spinning too fast, which caused noise. So they governed the speed on those, too. Solved with SMC Fan Control.

I wasn't too happy about being somewhat deceived by their specs for my equipment, even if they thought their intentions were "good".

Thanks! I was just thinking I might take a chance, but at this point I'm actually thinking about reinstalling what came with the machine. These new operating systems are literally making me angry.

This comment just made me realize why most computers sold today wouldn't work in vacuum of space. Even if we shielded it from radiation, they'd just fry to death.

Yeah, but they've been doing that for years. Remember all the people burning themselves with Macbooks?