First post, by Kordanor
I am currently looking for some "best usecases" for downclocking a SS7 board, either manually or using one of the K6 II+ III+ CPUs, without disabling the cache.
I looked into a lot of games already, but most often the lowest CPU Speed of 133Mhz or 166Mhz will not give a significant improvement as the more problematic games mostly expect a 386 or 486 up to 66Mhz or so.
Meaning you definitely have to disable cache. But of course at that point you also don't need the different CPU speed options of a K6 II+ for example.
Let's take Theme Park for example. On 133Mhz the game will still run much too fast, unless you go into high resolution mode. But then the animations in the menus are still screwed. The only option to make it run "right" is to disable the cache.
Games where it can be already enough to downclock seem to be mostly turnbased, where the faster CPU is only causing some animation speeds which can be reduced. Like the screen transitions in Colonization, or how fast the credits show in Jagged Alliance 1.
But games in realtime / actiongames are usually not fixable with downclocking. Or maybe I just didnt find good examples yet.
I know the list at: https://www.vogonswiki.com/index.php/List_of_ … sensitive_games
And I am still working my way through, but so far, the fix for most games is to disable cache, and reducing the clockspeed doesn't do much. Besides of the ones which straight crash if the CPU speed is too high (error 200). Also with some games on the list I couldnt identify the issue.
To me it feels a bit like the major profit of a K6 2+ with these games in particular is actually the higher clockspeed. As disabling the cache makes the PC very slow (maybe 486 50-66Mhz) while 133Mhz with active cache brings it to about a Pentium MMX 200-233Mhz This leaves a bit of a gap, and the higher clockspeed allows for slightly better speeds when the cache is disabled. Using PCBench compairon here, I can get a PC Bench 1.0 Score between 20.9-40.4 without cache, and a PC Bench 1.0c score of 148,7-466 with Cache.
Are there any games where you are glad you can just reduce the multiplier to fix speed issues without disabling the cache? In particular I am interested in games where the speed difference is very visible on screen (like in themepark).
The best case I found so far is a shareware game called "Roball", where with 400Mhz it's basically almost instant death, and with 133Mhz the game seems to work perfectly (actually same as if you disabled cache).