Q: is there a way to stop or bypass generating previews while editing?

while editing, it takes FOREVER to process the image i'm working on - when i check activity, it shows that it's generating previews.... i don't understand the need to generate so many previews - and the previews are not always related to the image i'm editing.  is it possible to bypass this function, in order to speed up the editing process?  please help.... editing is just SLOW and majorly hindering progress.