The 2000w PSU is not platinum, in fact it's silver but pretty close to gold. It's younger and stronger 2500w brother is gold rated, though. The 2880w beast is not actually platinum either, it is solidly in silver territory. I measured about 87% efficiency. Everyone confuses it with it's younger, slightly more buff 2980w brother the
39Y7414 is platinum, and much more expensive on ebay. We're all buying the 39Y
7349 which has no official efficiency numbers anywhere that I can find as it's too old to have been put through the 80+ testing program. My own testing though, puts it at about 87% efficiency at 50% load.
The 2980W 39Y
4714 shows a little over 94% efficiency at 50% load verses the 1880W 39Y
7349 at your stated 87% at 50% load.
So, let me make sure I understand this correctly;
If we had an S7 that we knew consumed 1210 watts [And used a 2980W 39Y7414 with 93% efficiency with approximately 40.6% load] we should see about 1,301 Watts at the wall on a watt meter.
AND
If we had an S7 that we knew consumed 1210 watts [And used a 2880W 39Y7349 with 86% efficiency with approximately 42.0% load] we should see about 1,407 Watts at the wall on a watt meter.
105 watts difference. It would be about the same with 2 x S7's on each PSU I believe. Let me see:
If we had 2 x S7's we knew consumed 2420 watts combined [And used a 2980W 39Y7414 with 93% efficiency with approximately 81% load] we should see about 2,602 watts at the wall on a watt meter.
AND
If we had 2 x S7's we knew consumed 2420 watts combined [And used a 2880W 39Y7349 with 86% efficiency with approximately 84% load] we should see about 2,813 watts at the wall on a watt meter.
So, my math is showing about 105 watts extra has to be burnt to power an S7 with the 2880W verses the 2980W. If we had 20 x S7's and burnt 105 watts more per S7 with the 2880W PSU, that would be 2100 more watts burnt. The price difference between each PSU is approximately $75 to $85. Let's use the $75 difference...
Converting that 2100 watts (2.1 kW) more power into dollars when using 10 x 2980's to power 20 x S7's:
730 hours in a month x 2.1 kW per hour = 1,533 kWh's in a month
1,533 kWh's x $0.10 per kWh = $153.30 saved in a month [All 10 x 2980W's paid for in 9.785 months; the price difference between 2980W & 2880W made up in 5 months]
1,533 kWh's x $0.09 per kWh = $137.97 saved in a month [All 10 x 2980W's paid for in 10.87 months; the price difference between 2980W & 2880W made up in 5.435 months]
1,533 kWh's x $0.08 per kWh = $122.64 saved in a month [All 10 x 2980W's paid for in 12.23 months; the price difference between 2980W & 2880W made up in 6.115 months]
1,533 kWh's x $0.07 per kWh = $107.31 saved in a month [All 10 x 2980W's paid for in 13.98 months; the price difference between 2980W & 2880W made up in 7 months]
1,533 kWh's x $0.06 per kWh = $ 91.98 saved in a month [All 10 x 2980W's paid for in 16.31 months; the price difference between 2980W & 2880W made up in 8.15 months]
1,533 kWh's x $0.05 per kWh = $ 76.65 saved in a month [All 10 x 2980W's paid for in 19.57 months; the price difference between 2980W & 2880W made up in 9.785 months]
1,533 kWh's x $0.04 per kWh = $ 61.32 saved in a month [All 10 x 2980W's paid for in 24.46 months; the price difference between 2980W & 2880W made up in 12.23 months]
1,533 kWh's x $0.03 per kWh = $ 45.99 saved in a month [All 10 x 2980W's paid for in 32.62 months; the price difference between 2980W & 2880W made up in 16.31 months]
That's about the gist of it. When I was looking into using those 2880w-ers for my farm, the 2980w-ers were quite a bit more expensive. I picked up 2880w-ers for ~$50 on average, and the 2980w-ers were not available under $300. They seem to have come down a bit now, though. I of course went with the 2880w-ers as I assumed they were platinum also since that's what I've seen everybody here call them. Measuring DC output and comparing it to AC input tells a different story, though. I've since converted pretty much every PSU in my farm to server PSUs with 93.5-94% efficiency (Which is pretty much Titanium rated) at 100% load as I tend to run them close to or pretty much maxed out. My power only costs about 6c USD, but the savings still add up with the gain in efficiency. The lower heat output is nice too, along with opening up capacity for a few more rigs to run on my pretty much maxed out 200A service.
I may look into the 2980w-ers now that they've come down in price along with j4abber's awesome breakout boards. The ease of use is unparalleled in the server PSU world thanks to his breakout board. My current PSUs require a lot of labour... Mostly soldering, but also rigging up the wires so they're "modular". An interesting fact to note is that the 2880W-ers are made by Astec, but IBM decided to go with Delta as the OEM for the 2980W-ers. Delta are also the OEM on the popular 2000W PSUs. I'm a huge Delta fan boy, every server PSU I run is made by them. They're pretty much top dog as far as I know.
