LOL...  I don't feel as bad now.

I must say, the new setup for the 2 x 2000 BB PSU's with voltage adjustment and digital volt meter is a nice set up as well.  Yes, the ability to choose fans to make it a quieter package is a plus [If noise is one's concern].  I say it all depends on what one plans to do and where they plan to do it.  If one wants less noise and the ability to over clock substantially, the 2 x 2000 BB setup with voltage adjustment is the way to go.  It would be my choice over the 2880 if noise was an issue and if I was not concerned about vertical headroom on my rack for more shelves.

My only concern with the voltage adjustment to over clock is "power efficiency."  Will the gains made from more bitcoin mined via over clocking with that setup trump the gains from a more power efficient PSU without overclocking?  The plus side from not over clocking is the potential for increased longevity of the blades in our rigs.  At least that's my opinion.  I'm open minded to any thing else someone would like to add.  I'm all about making the right decision.  I just feel this is important if one plans to have a lot of rigs powered by a lot of PSU's.  Making the correct decision on the right PSU for your long term plans is extremely important.

Wow, thanks for that info.  It's nice to know my investment has more features than previously known.  I mainly got them for switching capability.

However, I would not mind have a new toy (meter) around the house to check the efficiency of new HW.  Thanks for the info on meters.  I'm researching them and pricing them now.

I appreciate you doing this.  By the way, what PDU do you have?  I'm sure you've mentioned it elsewhere in another thread.  I need to get another PDU very soon before my power upgrade.  I wouldn't mind having a 240V PDU that gives decimal point reading as well.


I purchased a 2nd one for the hell of it.  One from NSR on eBay and one from NSR on Amazon at $150 each.  Even at 4 or 5 percent difference between the two models I believe it's worth it in my case.  My plans are to have 120 to 220 x S7's [or equivalent] by this time next year.  Which means I'm going to need much more than the 17 x 2880's I have at present.  I'm kind of laughing at myself now for buying the 8 x Corsair AX860's when I first started back in September, 2014.  It definitely pays to do your homework before taking the plunge.

Soab,

What did you end up doing for a power switch, if anything?

I believe I prefer the breakout board.

I liked this data sheet and wanted to make sure it remains.  So, I quoted it.

By the way, does anyone have a specification sheet on efficiency for the IBM 2880?

That was the only thing I knew to do as well.  My PDU's have meters but they are whole numbers with no decimal points.  It simply rounds off to the nearest whole number.  I'm going to do a search to find something better if possible.  By the way, I have the APC7911 "Switched" PDU's.  I have not hooked them up yet.  They too are metered.  However, I'm not sure if they have decimal point or not.  Do you?  I have to run another 30A outlet to plug it in.  I do not want to unplug the PDU's I have going at the moment.  They have rigs mining on them.

If you happen to know of something I can get on Amazon and/or eBay that can measure properly without spending too much money, let me know please.

If it's anywhere, it will be in this thread I believe:  https://bitcointalk.org/index.php?topic=893159.0

I remember that data sheet.  I was trying to find it last night but could not.  I wanted to see what "model" it may had referred to.

I honestly believe the 2980's will be at least 6% more efficient at a minimum than the 2880's.  80+ testing procedures did not begin until late 2004.  Which see:  https://en.wikipedia.org/wiki/80_Plus

Who know's how long it was before IBM got around to getting their blade center PSU's rated?  They may not have sought getting them rated until they went with more quality design and components to get as high of a rating as possible for marketing purposes.

"The Climate Savers Computing Initiative efficiency level targets for workstations for 2007 through 2011, correspond to the 80 Plus certification levels. From July 2007 through June 2008, basic 80 Plus level (Energy Star 4.0). For the next year target is 80 Plus Bronze level, the following year 80 Plus Silver, then 80 Plus Gold, and finally Platinum."  https://en.wikipedia.org/wiki/80_Plus

It really wasn't over night either with the creation of the 2980's.  They were made available in late 2010 to 2011.  The 2880's were out for quite a while before the 2980's came on the scene it appears [Maybe 2004 or 2005].  I would have to go along with Prelude on this one at the moment with the 2880's probably being around Bronze and no higher than Silver.  Even if the 2880's are equivalent to a Silver rating, this makes the 2980 a much better buy for one who intends to have a lot of gear mining.  At least after I did the math it appears to be the case.

I just paid $150 with free shipping for a 2980 on eBay.  It's supposed to be here no later than January 7th.  I'll get back in touch.  However, I do want some suggestions as to the best possible tool for measuring the amperage.  If it cost a couple of hundred dollars to purchase it, so be it.  The kilowatt meter I bought on Amazon was a piece of crap.  He went out on me after about 30 days.

Agreed...  But these are S7's

About to get in the shower then go to watch the 10:15am showing of Star Wars The Force Awakens with my son.

Slowly getting closer but no dice...

One rig with best share at  22,703,091,873 [Still a long ways off] and one rig with best share at 9,903,176,784 [Still a very long ways off].

I can agree with your assessment.  I'm searching the web now for specifications.

Look at the following link for the numbers on the 2980...  There are no numbers on the 2880 except for those done by members in the forums.  Prelude used a watt meter to check the efficiency at 50% load for the 2880.  He said it was more like 87% at 50% load.  Here is the link for the 2980:  http://www.plugloadsolutions.com/psu_reports/IBM_39Y7414_2980W_SO-188_%20Report.pdf

EDIT:  There is a possibility I'm off by 1%.  Even at 1% off on my figures, the 2980 is still very much worth getting IMHO if one is using MANY PSU's with MANY rigs.

You may be correct.  I'm not familiar with what percentage puts one in silver, gold, platinum and titanium.  Maybe I should not have used that terminology.  However, I believe if one looks at the actual numbers, they can see the logic behind the power savings which opens up more available power for more revenue.

EDIT:  By the way, Prelude, did say the 2880 is more in "silver" territory than gold or platinum.  I quoted him in my post above.

I appreciate the thorough review of both the IBM 2880W and the IBM 2000W PSU's.  However, I think one more IBM PSU should be thrown into the mix once it was brought to my attention that it existed.  The PSU I'm referring to is the IBM 2980W.  However, it has it's plus and minus' as well.  It depends on your goals and what you want to accomplish over the long haul.  

CONS FOR THE IBM 2980:

#1) - A "used" IBM 2980 is going for approximately $150 with free shipping.  A used IBM 2880 can be purchased in a range from $50 to $85 with shipping included.
#2) - The IBM 2980 and 2880 with b/o boards will be louder than the setup with 2 x IBM 2000 BB's with b/o boards depending on the fans you have chosen and the rpm's of those fans.
#3) - You cannot "easily" increase or decrease the output voltage for some serious under clocking or over clocking like you can the 2 x IBM 2000 BB's with b/o boards and added voltage adjustment.
#4) - [For someone to add in case I forgot something]


PROS FOR THE IBM 2980:

#1) - The power efficiency is better than the 2880 and the 2000 BB w/o voltage adjustment which cost extra for the 2000 BB.  More on this subject provided below:
#2) - The better power efficiency saves money on monthly power bill
#3) - The better power efficiency allows for an extra S7 or A6 to be added for every 6 x 2980W's purchased.  If you are using a lot of them or have plans to, the extra rig for every 6 x PSU's is more money in your pocket.
#4) - The costs difference between the 2980 and the 2880 or 2000 can be recouped rather quickly [Depending on power costs; as shown below...].
#5) - Takes up less head space than the 2000's.  This may be a concern for those with lots of rigs on lots of racks going up vertically on multiple shelves.

So, for me, [with plans on 200+ rigs in the future] it is more beneficial to purchase the 2980's with b/o boards.  Noise is not an issue for me.  The 105 watts saved for each S7 I'm running adds up.  105 x S7's connected to all 2980 PSU's adds up to 10,500 more watts available for 8 more S7's to gain more revenue.  So, I would say it depends on your plans as to the way one should go.  My opinion is if you are concerned with noise, the 2000's with b/o boards is the way to go.  If you are concerned with power efficiency and the ability to increase revenue because of better power efficiency, the IBM 2980 is the way to go.  

Also, I have no numbers on the IBM 2000's.  Yes, one could under volt the 2000's for better power efficiency.  However, one is lowering their hash rate and losing revenue in the process.  The 2980 enables better efficiency without losing hash rate and increasing the availability for more power for more revenue..

Here is a copy of what was posted in the S7 Forum regarding power efficiency:  [Please correct me if I'm wrong]


The 2980W 39Y4714 shows a little over 94% efficiency at 50% load verses the 1880W 39Y7349 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]

LETS NOT FORGET THE EXTRA 2,100 WATTS AVAILABLE IN THIS SCENARIO ALLOWS FOR AN ADDITIONAL S7 FOR MORE REVENUE WITH ROOM TO SPARE.

I suppose I should have covered up the sign in the photo and AT&T former data center.

I believe you're right.  You've had the 2880 long enough to know.  You also provided the data sheet on the 2980.  I'm quite certain you are correct.  I'm planning on purchasing at least 16 of them over the next 3 to 4 months.  It depends on how soon I get my power upgraded (increased) here at the house.  

I'm hoping to get a $0.062 per kWh rate myself for the following facility:  I need to talk with my power company to see what the requirements will be for that rate.  Otherwise, I'm not going to lease the 5,000 to 6,000 feet I would like to lease.  If I can get that rate, I won't have enough rigs to justify leasing the place until 3 or 4 months from now; unless I was to partner up with someone.  I've covered up the address to it's location in the screenshots.

I'm interested with anyone's thoughts on this data center being able to keep it cool enough for 200+ S7's?

The main reason I chose the 86% number for the 2880 is after looking at the numbers on the data sheet for the 2980.  The wattage on a single S7 falls below the sweet spot for the 87% efficiency and 2 x S7's are too high for the sweet spot for best 87% efficiency.  Hence, the 86% number instead of the 87% number.

Thanks again for sharing your opinion.  I believe I've pretty much convinced myself to get the 2980's from this day forward after listening to you and doing some research myself.