Add2PSU: More power for your mining rigs

[Miner99er]

So... 1200w PSU's costing $239 got you down?

Wish you could get 2 600w PSU's and do the same thing?

Maybe a 300w for the system and 900w your dual 6990s and save some money.

http://youtu.be/WsWdOMbQF94

Yes you need 2 (or more) Power cords... but it's an alternative to the dual PSU 24pin adapters from cablesaurus.

Or if you're like me and you have a crap ton of 300-400 watt PSU's... put them to work.

[grue]

you can just connect the green+one black wire from the atx connector to all the other supplies, and it will also work

[notme]

you can just connect the green+one black wire from the atx connector to all the other supplies, and it will also work

Indeed.

[BkkCoins]

Those 1200W power supplies pay for themselves quite quickly as they are usually 80 Gold rated. That means about 90% efficiency compared to 70% on old units.

Work it out,

eg. System needs 900W

@ 70% thats 1286W at wall.
@ 91% thats 989W at wall.

Saving 297W at wall 24/7, or 213 kWH / month.

@ 0.10 kWH that is $21.30 per month electricity saved.

How long do you plan to mine for?

The problem with high end power supplies isn't cost but having to spend the money up front.
If you really can't afford up front cost then you're forced to pay each month in lost efficiency.

The better quality and 5 year warranties are a bonus too.

[kano]

Certainly seems to be the case ...

I've got a 6950x2 rig (small and new)

I added the 2nd card after everything was running for a day and immediately exceeded the PSU limit
My PSU is a GE-P610A-C2 which seems to be not too bad but the limit wasn't far above 620W (power meter attached)

Since it was late night when I did it, I just jerry rigged a 2nd really cheap power supply I had lying around

Anyone who actually needs to do that (as already described above) it is just joining the PSON to ground
as in this picture I created from web site that took 5 pages to describe the process that only needs one picture
Also note the pin shapes are shown from above (where the cables are) not below
Or more correctly, the connector on the MB view: http://kano-kun.net/bit/PSUJumperOn.png

Anyway - yep the power usage jump for the 2nd card was very high - certainly must be due to the cheap PSU

One extra suggestion ... I find the power levels go quite a bit above stable running level when I start mining and then settle quickly
So consider that when buying an expensive single replacement
(or get a $20 Watt Meter and see what you really need - I hate looking at it coz I feel bad seeing how much power my rig is using    )

[Xephan]

Those 1200W power supplies pay for themselves quite quickly as they are usually 80 Gold rated. That means about 90% efficiency compared to 70% on old units.

Work it out,

eg. System needs 900W

@ 70% thats 1286W at wall.
@ 91% thats 989W at wall.

Saving 297W at wall 24/7, or 213 kWH / month.

@ 0.10 kWH that is $21.30 per month electricity saved.

How long do you plan to mine for?

The problem with high end power supplies isn't cost but having to spend the money up front.
If you really can't afford up front cost then you're forced to pay each month in lost efficiency.

The better quality and 5 year warranties are a bonus too.

Double teaming PSU works for newer PSU as well you know?

If I run 2x6990, each takes about 400W to 450W when clocked up so about the same as your 900W base system.
Hooking up a pair of 600W 80+ Gold is US$220 from Newegg, this puts the PSUs load at 75% which is just outside the typical optimal efficiency range. The cheapest 80+ Gold 1200W (also loading at 75%) from Newegg is US$260 after rebate.

So a $40 savings with no efficiency lost and added redundancy in that, if one of the 600W craps out, you can unhook it and run a single 6990 first. If the 1200W craps out, you can't mine until a replacement is shipped

[BkkCoins]

Double teaming PSU works for newer PSU as well you know?

If I run 2x6990, each takes about 400W to 450W when clocked up so about the same as your 900W base system.
Hooking up a pair of 600W 80+ Gold is US$220 from Newegg, this puts the PSUs load at 75% which is just outside the typical optimal efficiency range. The cheapest 80+ Gold 1200W (also loading at 75%) from Newegg is US$260 after rebate.

So a $40 savings with no efficiency lost and added redundancy in that, if one of the 600W craps out, you can unhook it and run a single 6990 first. If the 1200W craps out, you can't mine until a replacement is shipped

I agree that's another way to go. I was looking at that too but the local prices for 2x 600W 80+Gold PSU were more than the cost of a single 1000W (only need 900W+). I'm not in USA. There aren't many (any?) 450W Gold PSUs or that would likely be more attractive.

[Xephan]

I agree that's another way to go. I was looking at that too but the local prices for 600W 80+Gold PSU were more than the cost of a single 1000W (only need 900W+). I'm not in USA. There aren't many (any?) 450W Gold PSUs or that would likely be more attractive.

Running a 900+ watt load on 1000W worth of capacity is a sure way to kill the PSU real quick. It's usually recommended not to load a PSU continuously beyond 80% to get the most lifespan out of it. So cheaping out initially will just cost you more in the end, even with free replacements, you'd lose the value of coins you'll mine during that week of downtime.

[BkkCoins]

Running a 900+ watt load on 1000W worth of capacity is a sure way to kill the PSU real quick. It's usually recommended not to load a PSU continuously beyond 80% to get the most lifespan out of it. So cheaping out initially will just cost you more in the end, even with free replacements, you'd lose the value of coins you'll mine during that week of downtime.

Except 900W is already "marked up". I actually need more like 750W real load.
Well, according to other similar rigs posted here anyway.

[Xephan]

Except 900W is already "marked up". I actually need more like 750W real load.
Well, according to other similar rigs posted here anyway.

lol, why didn't you say so earlier? Obviously teaming up PSU isn't as cost effective at "mainstream" power levels if you don't have cheaper 80+ gold PSU at lower capacities available.

[kano]

OK I've got some rather amazing proof of a directly related issue ...

DONT use cheap PSU's as a 2nd to a good PSU

As I mentioned further up the page ... I did exactly that coz it was late at night when I got around to adding in a 2nd 6950 to my rig ... and found my 620W wasn't enough to handle start mining (even if it did drop down after with low settings) - thus the 2nd PSU.

Now I've been running settings to the max for the last day coz I got sick of having to keep them down low ... max was on 770W - seriously!

Tonight I finally got a 'relatively' good 2nd PSU (820W) as the 2nd PSU (to replace the cheap one)
My watts are now 430W - unbelievable.

Now as for using 2 good PSU instead of one expensive one ... Not sure.
Price for a single in the 1000W area is certainly more than 2 lower watt ones (for me a 820 + 620 was $100 + $65)

Anyone else got some real figures that they measured?
Coz my 430W to do 705Mh/s (current non-optimised - running for 50 minutes) doesn't seem all that bad for 2x6950 ...

[Xephan]

OK I've got some rather amazing proof of a directly related issue ...

DONT use cheap PSU's as a 2nd to a good PSU

it's actually: Don't use crap PSUs. Nevermind second or first or whatever

Cheap PSU (regardless of what is printed on the labels) are usually low efficiency units, we're talking about anything from 60~70% with designed capacity lower than what's on the label.

As I mentioned further up the page ... I did exactly that coz it was late at night when I got around to adding in a 2nd 6950 to my rig ... and found my 620W wasn't enough to handle start mining (even if it did drop down after with low settings) - thus the 2nd PSU.

Now I've been running settings to the max for the last day coz I got sick of having to keep them down low ... max was on 770W - seriously!

Tonight I finally got a 'relatively' good 2nd PSU (820W) as the 2nd PSU (to replace the cheap one)
My watts are now 430W - unbelievable.

Now as for using 2 good PSU instead of one expensive one ... Not sure.
Price for a single in the 1000W area is certainly more than 2 lower watt ones (for me a 820 + 620 was $100 + $65)

Anyone else got some real figures that they measured?
Coz my 430W to do 705Mh/s (current non-optimised - running for 50 minutes) doesn't seem all that bad for 2x6950 ...

It sounds a bit fishy if your 620W can't handle 430W worth of load.
What models exactly are your PSU?

I use a single 750W putting out 445W for and average of 800Mh/s on a system not optimized for mining.

[kano]

Well the figures may be skewed due to: my meter may or may not be accurate.

I'm getting a new better one next week on suggestion by someone on ozcoin who seems to know what they are talking about ...
Interesting to see if my cheapo one is accurate or not.

I'm not actually expecting it to be wrong (since it really isn't hard to accurately measure 2 of V, I and R)
... so I'd be surprised if a cheap one couldn't give a reasonably accurate Watt value
(yes all the other crap it does I don't care about, but the basic Watt reading is what I want and really shouldn't be hard to get accurate)

I'll re-measure both the old and new setup with the new meter ... since I'd also like to know if the cheapo one is OK to use elsewhere
(my server room UPS, 3 servers, switches, routers, HQ KVM, etc all runs off one point that would be good to know how close to 10A it actually is)

[Xephan]

Well the figures may be skewed due to: my meter may or may not be accurate.

I'm getting a new better one next week on suggestion by someone on ozcoin who seems to know what they are talking about ...
Interesting to see if my cheapo one is accurate or not.

I'm not actually expecting it to be wrong (since it really isn't hard to accurately measure 2 of V, I and R)
... so I'd be surprised if a cheap one couldn't give a reasonably accurate Watt value
(yes all the other crap it does I don't care about, but the basic Watt reading is what I want and really shouldn't be hard to get accurate)

I'll re-measure both the old and new setup with the new meter ... since I'd also like to know if the cheapo one is OK to use elsewhere
(my server room UPS, 3 servers, switches, routers, HQ KVM, etc all runs off one point that would be good to know how close to 10A it actually is)

Yeah, a basic wattmeter isn't that high tech and at the power levels we're looking at, even the typically poor resolution (+/- 5~10W) isn't going to be real problem. So it'd be interesting to see how much you actually draw.

On the other hand, I made a mistake about my PSU load, it's closer to 380W, 445W was at the wall with 85% minimum efficiency.

[Su100]

I have just received the order from David and to be honest - generally I am a very high expectation customer.

I emailed some questions at the add2psu.com on Feb 9. Within an hour I got a reply to my questions. I didnt understand something - so asked for a phone number. Received a reply with his phone number within next 10 minutes. Called him, he personally replied to me over the phone, and I ordered the items the same day - Feb 09. I am checking the envelopes - he sent it the same day I have placed the order. Absolutely prompt guy.

Today - Feb 18 - I received the items in my mailbox in Slovakia. In 9 days.

He advised me how he is gonna send it so customs dont bother me, no extra tax, no customs, items received nicely packaged and I even got some extra pieces for free.

I cant be more positive about my experience with add2psu:-)

Highly recommend.

Su100

[InCoinsITrust]

Are you advrtising them ? How much did you pay ? Where are they located ? China, US ?

[Pentium100]

http://youtu.be/WsWdOMbQF94
Or if you're like me and you have a crap ton of 300-400 watt PSU's... put them to work.

It's nice that they are using a relay to control the slave PSUs. That is better than the usual "connect all green wires together" method.

However, while you can use it like this, you cannot plug one device (video card, big BTC miner) to two different PSUs without special load balancing circuit (like it is done for dual PSUs in servers etc). You can however use the slave PSUs for video cards (one PSU per card) or separate miners (one PSU per miner).