The driver is required to activate the L2 cache. Otherwise, the CPU module will work fine. A G3 without cache is virtually the same thing as a 603e. I have that same processor upgrade for my 1400cs. It's a nice little card. It's too bad some of those upgrade manufacturers went out of business. It would be nice to have the same selection that we had back in the heady G3 days...

Peace,

Drew