I have successfully changed the bus speed of the 7" Card from 33MHz to 40MHz, resulting in a 120MHz CPU speed (stable as it seems).
On the back of the card, turn the resistor R69 90 degrees to the left (connect it to 5V) onto the bottom pad of the resistor R72.
This changes the input S0 of the SC464 to high which results in the following:
Not every 7"-card may take 120MHz. But i have an IBM 5x86 which are known to be have binned better than Cyrix own CPUs. AN IBM 100MHz part is basically comparable to a Cyrix 120MHz part.
Quake went up 19% from 9.8fps to 11.7 fps and the super scape benchmark goes 25% up from 50 fps to 62.5 fps which is more than expected.
There seems to be some more tweaking possible since writing is not cached at all and this reduces memory throughput to about half of what is normal.
-Jonas