On recent auto upgrage to 6.4.7.2 (x64) Loading and any use or saving of a spreadsheet is unacceptably slow. Spreadsheet is ~1.2Mb on disk. 18 columns, ~900 rows, a good few but simple formulae. One graph covering much of the data. Until the update used to work fine except that it once was similarly slow, but not as bad - cured by a tip found on-line to disable "rendering" (I don't remember details and cannot now find the tip. Task Manager shows memory usage over 50% but nowhere near 100%. Occurs regardless of other tasks running. (Open Office calc is also a bit slow now, but useable.)
MORE: Actually I *think* it was anti-aliasing that I turned of last time to restore speed. That did not seem to work this time but disabling "Use open GL for all rendering" in the Options / LibreOffice / View page and re-starting does seem to have recovered the speed of operation. So on the air again, and I will remember what to do next time, but it would be good if this setting was preserved during an auto-update. Tim.
Great you noticed it was OpenGL related! In general, you can use this to do the first checks: https://wiki.documentfoundation.org/QA/FirstSteps In future version OpenGL will be removed and be replaced with Skia. Meanwhile, it may help you check you got last version of your graphic driver + Windows udpate Since you found the way to make LO full speed again, let's put this one to WFM then.