.SKP & .STEP Accurate Blank Motherboard & PCIe Card Models 2015-12-14

This is what you need to begin your computer case design.

This helped me make fewer prototypes.
Its a very good tool for case design basics
I have been using this for validation as well

Exactly what I needed to start case design. Not new to CAD, but this definitely helps.

This is the best reference I have seen. Thanks!

This is awesome. Imported to Fusion and everything was nicely organized so I could delete everything except the ITX board which I wanted. Thank you!

Josh | NFC's endorsement is good as gold.

Well organized, acurate, and overalll good all around.

Amazing. Helped me in designing my case.

It's a real nice resource. Perhaps the only bit to fault it on is that it'd be nice if it included just some lines to show the maximum height motherboard components can reach in each area (as that can be quite useful).
I'd love to see some of these resources for other components too, like common sizes for PSU's (even though they don't follow a standard), and it'd be quite nice to see it for 2.5", 3.5" and 5.25" drives...

Been going nuts trying to find proper dimensions of PCIe slot, even from official spec sheets. The few bits of data I managed to piece together match up with your models, so I think it's safe to assume I can trust the accuracy to fill in the rest of my missing data.