Benefits of x87 over SSE

Question

I know that x87 has higher internal precision, which is probably the biggest difference that people see between it and SSE operations. But I have to wonder, is there any other

Answer 1

Conversion between float and double is faster with x87 (usually free) than with SSE. With x87, you can load and store a float, double or long double to or from the register stack and it is converted to or from extended precision without extra cost. With SSE, additional instructions are required to do the type conversion if types are mixed, because the registers contain float or double values. These conversion instructions are fairly fast but do take extra time.

The real fix is to refrain from mixing float and double excessively, not to use x87, of course.