So it will be a double post - but meh it's my thread...
So... here is the results of the delid... very, very happy with the results. Chip is still totally voltage limited... I was able to pull this off:
However, in running Prime95 for 30 minutes at that speed & voltage... I never had a core over 74C!
But 5.0GHz was still a no-go... and I consider those voltages on 4.9GHz to be fairly suicidal for daily use (not to mention unnecessary)... so I'll be running @ 4.7 now which was stable before at 1.4V - but had a core top out at 100C after a few hours of Prime95 so I shut that down and had been running 4.5GHz as shown before. However, if you want a good example of how well this thing can wick the heat away now... here's an IBT run at 4.8GHz @ 1.456V vCore:
(Highest core temp at 73C now... so 6C down on the hottest core... and 300MHz up
Here is the result at the same settings I ran the pre-delid run at (4.5GHz@1.256V vCore):
Now hottest core is 58C! Down 21C from pre-delid values and now the difference in core temps is a much nicer 4C with an average of 56C across all 4 cores... with IBT - with Prime95 I would expect to never see anything over ~54C in a 24hr run.
I've started a 24h run at 4.7 which I expect to finish with temps peaking in the mid 60s...