Unless you run spreadsheets on it, then probably no difference.
Games that run decently on a 386 don't use an FPU. Windows 3.x/9x GUIs don't use it either.
You can run Quake, though.

My family put a 387 on our 386SX back then hoping it would help games. It was useless, and I think the severe flexing we did to the board trying to push it into it's socket might be why the PC started locking up a few months later. After the PC was unusably dead, my dad tore the 387 back out and took it to work for his spreadsheets. At least somebody got something out of it.
I guess they didn't have IT departments back then.

Someone posted a German article on here years ago that purported to test the win 3.1 GUI with a copro and show a noticeable improvement

maxtherabbit wrote:

Someone posted a German article on here years ago that purported to test the win 3.1 GUI with a copro and show a noticeable improvement

Disk caching can be faster if the software uses the FPU for processing virtual memory

You can upgrade just for the good feeling 😁

Some games like Falcon 3.0 use it, some applications also use or require it (AutoCAD...). But you'd already knew this if it was the case.

rmay635703 wrote:

maxtherabbit wrote:

Someone posted a German article on here years ago that purported to test the win 3.1 GUI with a copro and show a noticeable improvement

Disk caching can be faster if the software uses the FPU for processing virtual memory

Uuh, tell me more about it! 😮

Regardless of the performance increase, 4 € for a 387 is a pretty good deal.

Ok i order today the i387 25 , i hope work fine in my 386 sx 25 , i want to read about the impovement in win 3,1 ,

really i can run quake in this machine ? it is only 4 megas ram , hd it is a compact flash 😀 , any other upgrade for this machine 😀

thx to all post

Quake needs 8MB to run. But it will be very slow... under 1FPS.