I was curious if there was a benchmark test that was available to compare CPUs that are 8-bit. People always like meaningless analysis to justify some decision, and I was curious if there was a historically relevant example. I found in literature the compression of Shakespeare using LZ, but I wasn't sure if there was a "main stream" comparison from the 8-bit era of computing.
There are three primary benchmarks used during this period. They are not strictly "CPU" tests, but were often used for that purpose.
The almost unknown Rugg/Feldman suite from 1977. This was a series of seven, and later eight, small BASIC benchmarks. They were clever in that each test was a modification of the previous so you only had to type in one or two lines - important in the terminal era. Although almost unknown in the US by 1980, it went on to have a much longer life in the UK where it became a standard of sorts.
The Byte Sieve, likely the most widespread. Intended to be a language benchmark, it was almost always seen as a machine benchmark using assembler versions of the code. It was seen in many languages on lots of platforms. Unfortunately, collecting data is somewhat difficult because the authors sorted in... an odd way. It was still in use well into the 1980s and likely the one you want to use if you're running a test today.
The Creative Computing test, another all-BASIC one but generally (and incorrectly!) often used as a machine benchmark.
For assessing floating-point performance, there was the Savage benchmark. It was proposed by Bill Savage of Microfloat in Houston, Texas, and published in the Ray Duncan column "16-bit Software Toolbox" in Dr. Dobb’s Journal, Number 83, September 1983, p. 120. A scan of the entire Dr. Dobb's volume can be retrieved here; the relevant article starts at page 561 of the PDF file.
The benchmark assigns
a=1 and then times 2500 repetitions of
a=tan(atan(exp(ln(sqrt(a*a)))))+1. With the software implementations of floating-point arithmetic available on 8-bit machines this typically took several minutes to complete, if memory serves.
The circa-1981 Byte Sieve benchmark may have originally been conceived as a programming language benchmark. But the algorithm consisted of such a simple set of intrinsic basic operations (adds, compares, indexed or calculated address load/stores, not much more) that it could easily be hand-coded or hand-translated to 8-bit ISA assembly language, and thus used to compare 8-bit processor system performance doing such basic ops.
(* but with current 32/64-bit multi-issue and multi-level-cached processors, hand-coding may or may not be as comparable across ISAs and implementations.)