Re: Image size increase after upload.
No... the original image will not change in pixelsize...
it will only change in quality if you set the original image quality in your settings..
if you upload a jpg that is compressed to 75% and you set the original image quality to 100% then it will increase in size.. (but the quality you see wont get better) ... set the quality to 75 or 80 % and it should decrease in filesize..(not in pixels)
if you are concerned by server capacity.. or webspace then set Save Original Files not to keep the original.. it will then be resized to 640x640... and you will not keep the original...
if you choose keep the original the size: 640x640 will only be applied to your "normal" or intermediate image.. the original image will remain in the original size but as said above you can modify the quality (btw setting the quality to -1 will keep exactly the same filesize)
hope that was understandable..