There were no 500MHz x86 processors in 1998. Pentium III wasn’t launched until the early 1999 and it wasn’t until well into the 2000s before games started requiring such beasts.
Myself, I played Half-Life on a 233MHz Pentium MMX, software rendered. It ran… adequately.
500MHz was not a thing in 1998, an expensive desktop PC was a slot based Pentium 2 350MHz in 1998. The 500MHz P3 came at least a year later and was quite high end for its time.
In early 1998 a more normal baseline home gaming desktop PC was like a Pentium 266 MMX.
Pentium 133MHz was coincidentally the fastest machine I had at the time but also the minimum spec labeled on the box. (my laptop had a Chips & Technologies 65550, so no 3D help there)
