Is this power saving worth it?

[MartinIAm]

I have a dell r610 and a dell r620. On my r610 I pull around 4 kilowatts per day. On my r620 I pull around 2.5 kilowatts per day. My r620 has double the load and double the ssds that my r610 has. I run these servers 24/7 and my electricity is around 7 cents per kilowatt. Is it worth it to sell my r610 (maybe around $200) and get an r620 for around $350 to save almost 2 kilowatts per day?

[brwainer]

$150 at $0.07/kWh gets you 2142 kWh. 2142 kWh at 1.5kWh per day (assuming the new R620 is on for the same amount of time) means it would take 1428 days (3.9 years) to recoup the cost. So only after 3.9 years would you overall have saved any money. However, that does not factor in that whatever R620 you get probably has a faster CPU, and/or more cores, and/or more memory, and/or the ability for additional storage. Unless you can place a monetary value on that, those are intangible and subjective benefits.

[zeusthemoose]

Cant comment on the actual gear, but the math itself I can. Assuming the $350 for the r620 is not including 200 off from selling the r610, it will cost you $150. At a 1.5 kilowatts a day saving (7 cents each), it will take almost 4 years to it to pay off. So assuming you are keeping it for more than that and the time spent upgrading is worth it, then go for it.