Norton System Info (SI)

Norton System Info was probably never meant to be as popular a benchmark as it became; it was a small utility that identified a system and, as an afterthought, measured the speed of the system relative to the performance of an IBM PC (the tool says “IBM XT” but they have identical performance characteristics).  For reasons I can’t remember, this Computing Index was quoted for nearly a decade in magazines and on bulletin boards as a way to compare performance (although PC Magazine took a stand against using it; you can read their stance on Norton SI in PC Magazine, September 16, 1986, page 131.)

The term Computing Index sounds pretty complex, but it wasn’t.  In fact, it was a laughably small metric that consisted of a single signed multiply and a single signed divide instruction that looped 100 times:

2EEF cmp word [bp-04],0064    ; Is our counter 0x64?
2EF3 jnc 2F11                 ; If so, exit the loop
2EF5 mov ax,004D
2EF8 mov [bp-06],ax
2EFB mov bx,0003
2EFE cwd
2EFF idiv bx                  ; 004d / 0003, ax=0019, dx=2
2F01 mov [bp-08],ax
2F04 mov bx,04D2
2F07 imul bx                  ; 0019 * 04d2 = ax=7882
2F09 mov [bp-06],ax
2F0C inc word [bp-04]         ; Increment counter
2F0F jmp short 2EEF           ; Start loop again

An afterthought indeed.

Norton wasn’t ignorant of the popularity of their benchmark, so from Norton Utilities 6.0 onward, they shipped a greatly expanded System Info utility which also came with an expanded Computing Index screen:

Unfortunately, the metric was still the same, because once it got popular they couldn’t change it (as changing the metric invalidates all of the previous published scores), and since later processors greatly increased their IMUL and IDIV instructions, the Computing Index was no longer reliable (tenuous as that was) as a metric for system speed.

You can download three different versions of Norton SI on the Other Benchmarks page.

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