No, this mod works with ANY psu that has the sense wires present.

And keep in mind that it works with supplies that have 1, 2, or 3 sense wires. All 3 do not have to be present to do a mod.

Also note that sometimes they shove the 5v sense wire in the middle of the ATX bundle versus putting it on the edges. Also, most of the time when only a 5v sense wire is present, that modding it also mods the 12v power rail as well.

I would open the psu and see whats there. You may find that there are VRs already included in the circuitry of the psu.