Oh trust me if I had had the money I would have happily pursued your route. Cutting a trace on your only working computer and soldering bits & pieces onto the motherboard in order to land a job (talk about risk/reward here, I'm not sure how I would have worked without that machine but I really wanted that engine ;) ) made me pretty nervous. If I could have saved myself that batch of cold sweat I would have happily done so.
What got me is that it did work, I fully expected there to be some level of synchronization between the chips that would require both of them to be clocked at the same rate. The only reason I tried this is that the main CPU appeared to stop working and I figured it was worth a shot to see if the FP could go faster. And it did, and not just a little bit faster! Apparently Intel engineers were quite friendly when they designed the interaction between the two processors because in spite of the huge discrepancy in clock speed between the two chips it worked incredibly well.
What got me is that it did work, I fully expected there to be some level of synchronization between the chips that would require both of them to be clocked at the same rate. The only reason I tried this is that the main CPU appeared to stop working and I figured it was worth a shot to see if the FP could go faster. And it did, and not just a little bit faster! Apparently Intel engineers were quite friendly when they designed the interaction between the two processors because in spite of the huge discrepancy in clock speed between the two chips it worked incredibly well.