Since I've upgraded my laptop from Windows 7 to Windows 10, my Minecraft becomes more laggy. So, I wonder if that was the cause of the lack of FPS in my Minecraft?
There would be a number of factors that would cause this following an upgrade.
Drivers - By default, windows 10 will use it's own reference drivers, over the optimized, more effective drivers produced by the hardware manufacturer. Make sure all your drivers are up to date AND Windows 10 compatible.
Settings - It's possible the upgrade has removed settings from your hardware, which results in performance losses. Check your settings are correct for your drivers and software.
Disk Space - Windows 10 Upgrade uses a fair amount of space for upgrade. You could possibly be running low, causing poor general performance (loading chunks from the disk etc). Perform a disk cleanup and (if you DON'T have an SSD), perform a full disk de-fragmentation
Running Programs - Some programs installed on your PC previously may not be fully windows 10 compatible. They could possibly not run as efficiently as ones which are. Ensure your programs are designed to run with Windows 10. Also, check that you are only running programs that you require. Unused programs will affect performance.
Background tasks - Windows 10 adds a lot of backround processes which could be affecting performance. Use Services.msc to find out whats running, and check web sources to discover if you need it running. Do this with care, as you can break your PC by turning off needed services. A number of these services are known data-miners, so you might be sending lots of data to microsoft that you really don't need to.
I've tried to present this list in the order in which I think is most likey causes for a slowdown following a windows 10 upgrade.
We could provide more specific answers, if we had an idea of your system specifications, and an overview of how your system is configured currently.
It shouldn't. I'm not an expert with computers, but when I upgraded to Win10 I didn't see a noticeable drop in performance. Make sure that your settings in Minecraft are where they were.
From what I've heard, the Window's 10 edition of Minecraft (as in, the edition made for Windows 10. Not the normal launcher that you get from minecraft.net) is laggy. I haven't bought it though.