Re: Historical evolution of CPU perf

On Wed, 9 Oct 2024 13:23:22 -0500
BGB <cr88192@gmail.com> wrote:

On 10/9/2024 11:33 AM, Stefan Monnier wrote:

I'm looking for a chart illustrating the evolution of CPU performance
(e.g. single-threaded or maybe performance per watt) over the years,
covering something like 1990-2020.
 
Any good candidates?
 

 
Yeah, I would also like something like this, or maybe some way to
"sensibly" compare the relative performance of modern stuff with vintage
stuff.
 
Like, for example, I can't make sense of whether the performance of my
current project is similar to similarly-clocked vintage hardware, or
potentially significantly faster.
 
Based simply on Dhrystone score, it would likely be placed in a similar
area to a 90s era PowerPC in terms of perf/MHz.
 
 
 
But, if I add an early 2000s laptop as a reference point, stuff gets
weird. In various benchmarks, the difference in performance is
significantly smaller than the relative difference in clock-speed.
 
Though, the laptop is also break-even with a RasPi2 in terms of general
perf (in theory, the laptop should be faster). Seems like the laptop
suffers a relative deficit in terms of memory bandwidth (*).
 
But, can note that Dhrystone doesn't really measure memory bandwidth...
 
 
*: The 100MHz DDR1 RAM in the laptop gets roughly 7x the memory
bandwidth of a 16-bit DDR2 chip being run at 50MHz. Sort of makes sense
if one assumes 4x the width and 2x the clock-speed.
 
I am not sure if just the laptop, or if RAM access in general was
proportionally slower in the 90s. Or, if it is just a case that late 90s
/ early 2000s, CPUs had gotten faster much faster than RAM had gotten
faster, so there was a performance lag here.
 
I suspect it may be the latter, if one linearly extrapolated backwards,
it would mean 486 PCs running at ~ 10-16 MB/sec for RAM bandwidth, which
in my own testing seems insufficient to run Doom at acceptable speeds
(actual 486's having no issues running Doom).
 

As a complete non-cpu chap, what I care about is (my) consumer experience;
- i.e no delays. So ditch the fancy graphics - get me a fast boot time and
a responsive OS. Only a few are doing FFTs & so-called AI.

--
Bah, and indeed Humbug.