Jumper settings for OPC 550?

Hi.

Does anybody know, if there are jumper settings for multipliers above 4.5 (4.5, 5.0 ang 5.5). I cannont find any hints inside the manual.

BTW:

From one day to another the K6 III 400 in my 550-card ist running very hot.
When I first run the application everything seems to be fine, but after only a few minutes Windows gets unstable and system errors occur. Then the card crashes and even switching to the mac is no longer possible, so I have to rebbot.

The CPU gets really hot, although the core-voltage is set to the desired 2.4 Volts an a rather big heatsink with fan is installed.

Can anybody help?

G.Brenke