Thank you for your report!
Saving/opening a file may not just rely on how fast your processor is, but it also depends on your hard-drive type. If you are still using an Hard Disk Drive (HDD) for saving the file, the bottleneck could be there. Solid State Drives (or SSDs) should be 3-5 times faster in reading/writing compared to HDD. The amount of RAM available for this process could also play some parts in this. If you run Archicad with many Chrome tabs opened, this could also slow down the saving process.
I hope this helps you with the issue!
Have a great day!
Technical Support Engineer