[tripdout]

7900X equivalent 9900X has 120W TDP as opposed to 170W. Is it that much more power efficient?

[Voultapher]

That 170W TDP was chasing the benchmark crown. The 7950X lost <5% MT perf when run at 120W.

[canucker2016]

The all-core max clock speed costs a lot of watts for that last 10% - close to 50% of total CPU consumption in some cases.

That's why undervolting has become a thing to do (unless you're an Intel CPU marketer) - give up a few percent of your all-core max clock rate and cut your wattage used by a lot.

[GordonS]

I wonder then if the 9900X could be undervolted without losing more than a few percentage points of speed?