Yes, it doesn't have an on-board VGA, but I do have another Turbo-switched S7 that does. Only 2 PCI slots will suffice for this board as the Apocalypse 5D has both PowerVR PCX2 and a 2D core on the same card. The other PCI slot will likely be a Voodoo 1/2...
Yes, it is indeed a feat, as it's very hard to get IA32 CPUs this slow. I do have another board that goes even slower - possibly even to an Intel 4004 speed range...
I've been really busy lately, but managed to get some tests done and formatted some datapoints from XT speeds to around a 486 for the time being - outlining the smooth scaling.
You can see both FSB and Multi scaling using the aforementioned baselines:
The cells highlighted in red are anomalies, where the expected Speedsys numbers are lower than expected. Bizarrely, they are slower with faster parameters...
Next, I've collated the datapoints to show the smoothness in scaling:
I stopped around Speedsys ~ 9, this is around where I de-turboed with all caches enabled, as seen in one of my earlier posts. The above datapoints have scaled up to just below that speed.
Below is a graphical representation of the above table:
More datapoints can be added to make the scaling even smoother... So, we've scaled from a PCJr/ XT to a slow 486. Here is the fastest Speedsys snapshot with Deturbo and only L3 Cache enabled:
I'll continue later with more scaling past 486 speeds and into Pentium and beyond... If anyone wants to see a Speedsys snapshot at a particular datapoint, then just let me know and I can post one here (they do take ages at the lowest speeds).