I've been trying to use Krita for a while now, but one of the biggest barriers I have is that it takes way too much in terms of my computer's resources. I don't know much about computers in general, but I do know that Task Manager says that opening a 40-layer 11.5" x 8.5" 300 resolution Krita file sets it at 3615.9 MB of memory. When I tried just hiding one layer the CPU got booted to 60% just with Krita. For comparison, I opened a 50-layer drawing, same proportions but double resolution, added some layers and drew over it a little (which I hadn't done after I opened the Krita file this morning), and started fooling around with the 3D capabilities in Clip Studio Paint, which never went over 550 MB of memory. I thought that maybe it was an issue with the file, but I tried opening a blank document, and it's sitting at 2,911 MB of memory. There's got to be some sort of fix. Krita is the best free graphic software I know of.

That sounds more like a memory leak than anything else. If you're using one of the newer krita's(like 2.9.6), there's a little resolution indicator in the status bar on the bottom. Hover over it(or just click) to get extra information about the data-usage... In fact, please make a screenshot of it so that we can see what is going on in detail.

I assume that the resolution bar is the one that has the image dimensions? I have a bar that says 4025x2975. I would assume that's what you're talking about, but the only thing that's responding to what I'm doing on the status bar is the zoom functions. I've clicked it with no response, and hovered over it for over a minute with no response.
Btw, I have version 2.9.4

Update to the newest version available on the website then. There's a good chance your problem is fixed, that'd be great right? If not, make a screenshot.

I updated it, and it's still at 1,800 MB memory. It's an improvement, but still nowhere near what I'd like it at. The screenshot is here http://i1055.photobucket.com/albums/s511/neverominin/yargh_zpsycqltkkw.png

Okay, that screenshot indicates that 1gig is what your image itself takes up. We cannot do anything about that, because that is as far as we know the only way we can keep the layer information stored. We have no idea what kind of hoodoo MS5 and Photoshop have in this case. (Though, it may be that you had several 8bit layers in MS5, that were converted to full color layers in exporting to PSD. Because you are using cmyk with transparency that would mean that each 8bit layer takes up 5times as much space now)

the remaining 800mb is either resources, or windows lying through it's teeth(we've had that too, but I am not sure if it applies anymore now you can set the swap)

TheraHedwig wrote:Because you are using cmyk with transparency that would mean that each 8bit layer takes up 5times as much space now)

Yes, what he said. CMYK is a much 'larger' colour format than sRGB. I would recommend working with sRGB until the point where you have to take your art-work to the printer, and only at that point convert it to CMYK. Or ask if your printer can accept sRGB files - which most printers can.