Also, you want a fast FPU to do openssl work [0]. A standard 8088/8086 without an FPU is going to need an FPU emulator which is a slow process. You essentially have to throw an illegal instruction exception each time you want to execute FPU code. Then catch the exception and then emulate the 8087 in software. All this takes dozen to thousands of clock cycles on a 4.77MHz CPU depending on the FP instruction. Spending thousands of cycles per FP instruction while interrupts were disabled was costly on machines before 486s. They simply didn’t have the speed to make FPU emulation standard. Many commercial compilers for C/C++, Pascal, Fortran, and BASIC had FPU emulators as does MicroWeb’s choice of OpenWatcom.
According to this benchmark, a low end 486/25MHz was over 1000x faster than a 286/6MHz with software FPU. The Pentium 10x faster still. [1]
[0] https://www.linksysinfo.org/index.php?threads/using-fpu-emul...