Ive found when using F5 bios UD4P,,

Hybrid mode is the best option to run when not using a X2 X3 chip.

The normal firmware acted funny when i used my Chips in X2 mode\X3mode and even my 9950 was buggy when trying to Oc like mad.

Hybrid Mode worked best for all my CPU's regardless of the Cores Type.

If you want o keep X3 or X2 the Stock core dont use ACC when using Hybrid.

ATM Hybrid just works