Well it's a bit late to ask i have that ordered and practically shipped, but still would be nice to know opinions.
Personally that would be right at or maybe above the limit even at 220V and I would not do that.
If you had an A741 and A721 setup that would be pretty good though two A721 would be overly safe.
1600watt PSU seem to handle the A741 even at full blast with a good overhead left over.
Personally I like to overkill the PSU so it has max efficiency, but hard to beat the 1600w PSU deal and has yet to cause an issue.
APW5 specs say it provides 2600w@220v (so its kinda 1300 per 741 in my case, and i have access to 230-235v voltage, so 220 is guaranteed) while A741 requires approx 1150w, isnt that enough?
I also have some APW3's on the way, though somehow APW5 for 2x741 seemed a nice option for tests.
My 1600watts are reading around around 1300 usage when they are running around 8TH. With -2 voltage via their setting, it drops around 8% but still has variation.
From the specs: ≈ 1150W, +0% ~ +15% So at +1 volt and 8.2TH+ it will be closer to 1355.
I'd ask them about it, they most likely have a solution.
Thanks for detailed info! Ill get in touch with'em and see what else can they suggest.