It should. At 80% load (20% headroom), the SuperNOVA 1300 G2 could theoretically support two OC'd S3s up to 520WDC each (1300WDC*80%/2)which equates to 578WAC at the wall at 90% efficiency. I think two CX750M is a better deal (also currently with a rebate) at the Egg. It offers additional headroom (14.5% more) and the flexibility of having an independent PSU for each OC'd S3.
I like the idea of two CX750M's for two S3's instead of a single PSU. It removes the PSU as a single point of failure. Also I'm deploying at a data center where we have two power inputs. Having separate power supplies allows me to spread the load.
Amazon has the CX750M for $69.99 (prime), which is a better price than NewEgg. Of course NewEgg accepts BTC now. I haven't been through the process, so I don't know how they compute the price, or if they offer a discount for using BTC.
The CX750M has an 80 Plus Bronze rating compared to the SuperNOVA 1300's gold. Assuming the rating is accurate, that just means that the SuperNova has higher efficiency right?
Does anyone have any negatives to going with two CX750M units?
The trade-off that obviously stands out (I don't consider it a negative since both PSUs have certain trade-offs as already mentioned) is the difference in efficiency as you already stated. At around 75% load, the CX750M 80 Plus Bronze is approximately
85% efficient while the SuperNOVA 1300 G2 80 Plus Gold is around
90%. Is the difference in efficiency relatively significant in terms of energy cost? Let's find out.
Let's assume that an OC'd S3 requires
425WDC from a PSU:
425WDC / 85% =
500WAC (draw at the wall with a CX750M)
425WDC / 90% =
472WAC (draw at the wall with a SuperNOVA 1300 G2)
500WAC - 472WAC =
28WAC (difference in at-the-wall wattage between the two PSUs)
Therefore:
28WAC * 24 hours / 1000 =
0.672kWh (difference in kilowatt-hour in a 24-hour period at this particular OC setting)
0.672kWh * $0.15 =
$0.10 (difference in energy consumption cost in a 24-hour period based on $0.15/kWh energy rate at this particular OC setting)
Of course, this would be a moot point if one has free electricity.
