This little chip came in the mail the other day and yesterday it went into my Budget 1997 OS/2 build.
I got some very noticable gains in DOS. Quake 320x200 went from 27,4fps to 34,1fps (+24,5%) and Doom went from 74,6fps to 85,4fps (+14,4%).
Obviously these are nowhere near the +40% you'd expect from the PR ratings, but to be honest it has more to do with Cyrix's inaccurate PR rating than AMD's, at least in DOS. It is possible that I will see more difference in Windows 9x - we will see.
Also, disabling the L1 cache using SETMUL seems to take the system down to about 486DX2-50 speeds or 486DX-25 speeds depending on which benchmark (NSSI, Norton SysInfo, etc.) you look at.
I haven't been able to run SpeedSys on this system, it hangs at "Reading MSRs" and requires a cold reboot for some reason. A search on VOGONS led me to this reply by Phil who suggests disabling some CPU related feature in the BIOS, which led me to this reply by unmei220 who suggests turning of Cyrix 6x86/mII CPU Detection option, which does not exist in my BIOS. Looking around on the internet I came across 6X86OPT 0.77 which apparently fixes the issue by CPUIDEN.EXE -unset which can actually turn off CPU ID for 6x86 processors, so I guess that will do the trick. If it works I will post screenshots of the previous suite of software I ran on the K5 on this processor as well, for comparison.
I will also mess around with Linear Burst options which seem to be fairly important for Cyrix 6x86 CPUs. Scratch that, no Linear Burst on 430TX.
All in all, it is becoming a well rounded 1997 Budget home workstation, I feel like. 😀
Retronautics: A digital gallery of my retro computers, hardware and projects.