Ah, so this is where the numbers get interesting (for me anyways). My current power cost per kWh is 0.13111 so lets run some calculations with that. I used a kill-a-watt to get these numbers for the E5-2675 V3 so the accuracy is probably not perfect, but close enough for our uses.
E5-2675 V3 Idle Wattage: 52 watts
E5-2675 V3 Load Wattage: 160 watts
E5-2670 (x2) Review Idle Wattage:
200 watts
E5-2670 (x2) Review Load Wattage : 375 watts
Current Midwest kWh cost: $0.13111
E5-2675 V3 Annual Costs
Idle: $59.72
Load: $183.76
50/50: $121.74
E5-2670 (x2) Annual Costs
Review Idle: $229.70
Review Load: $430.70
50/50: $330.20
Additional Cost to run 2x E5-2670 V1 (E5-2675 V3 as 0)
Idle: +$169.98 ------------------ 3 Year Cost = +$509.94
Load: +$246.94 ---------------- 3 Year Cost = +$740.82
50/50: $208.46 ---------------- 3 Year Cost = +$625.38
Now, this doesn't seem
that bad but unfortunately I am moving soon to somewhere with much higher energy costs. So lets just see how things look with the new 0.32111 kWh cost.
Future kWh cost: $0.32111
I won't go through the entire calculations... but things get pretty damn ugly here.
Total additional cost to run the dual 2670 V1 box at just idle year around is $416.31. Over three years, that adds up to an additional $1248.93.
With that said, I have heard some rumblings from various forum posts that a dual 2670 box can actually be around 100 watts at idle with all power saving features turned on. With that in mind, you can just halve the cost savings.
In either scenario, I would personally rather go with the newer platform. Also, just a quick disclaimer that this is all some napkin math so I could be off on some stuff.