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So now I figure I should learn the basics on how to properly balance the load on a PSU.  

I was obviously just working the 4 year old PSU too hard, and had connected the power cables all haphazardly not paying attention to amps, or rails, or any of that stuff.  

So now I come to you guys for an education.  In simplest terms, how do I figure out what to connect to what?  

Example:  Say I have a 1050W PSU that has this:  +3.3V@24A, +5V@30A, +12V1@20A, +12V2@20A, +12V3@20A, +12V4@35A, +12V5@35A, +12V6@20A, -12V@0.5A, +5VSB@5.0A

8 SATA connectors & 4 PCI-E connectors & then the regular assortment of molex.  

I need to connect 4 HDDs, 1 SSD, 1 DVD, MB, CPU, and 3 5830s.  

How should I connect this to safely load the PSU?

I can only tell you a common sense approach. That is too much stuff. Get another power supply and use both. I does not have to be expensive or even new.

I just don't think that's the case.  A 1050W PSU should be able to handle this.  HDDs don't draw that much, and neither do 5830s.   

It is really east to do, I promise. 

I'm buying a Kill a Watt as we speak.  But nevertheless as far as load balancing, does anyone have any suggestions on how to read the specs on a PSU and then apply the knowledge obtained by reading those specs? 

cards on this rail:
+12V4@35A, +12V5@35A

board on any of the 20A rail

alternatively if the board is on the 35A rail by default just put a 5830 on any single 20A rail

Negative.  That's not even close to loading a 1050W PSU.

That makes sense.  I guess I'm missing a more fundamental question:  How do I know which rail is which?

I can't be bothered with load balancing. That is why I always get a single-rail supply. Why don't you?

Well here's the thing, my guess is that PSU is not super high quality. The specs listed are the usual nonsense I remember seeing with low quality PSUs, notice that the total Amperage of the 12V rails combined is 150A. ?? @ that (thats like 1800W...).

Likely there is some crazy ass internal structure to this that distributes whatever load it can actually handle amongst the rails in some twisted shared fashion that isn't worth figuring out. Back when I used to be really into hardware, I counseled people all the time that just because a PSU is "1000W"+ doesn't mean it can handle any kind of load on it. My suggestion is simply get a quality PSU and then forget about it, it's worth the extra $20 by far, more than any other component (except I guess GPUs for miners).

Some people have a hard time believing me, but I ran a Seasonic X750 Gold PSU with 4 5870s overclocked at full load for a few weeks straight (before my 1200W shipped). It ran at scary hot temps, but didn't miss a beat powerwise, and once I got it transferred to a slightly less intense system, put out the sweet stuff for my second rig for months on end.

So my recommendation is to make sure you are purchasing quality, at least on a PSU.

Here's how you load balance a power supply.

Step 1: Sell the multi rail PSU on eBay
Step 2: Buy a single rail power supply
Step 3: ???
Step 4: Profit.

Any of the Rosewill CAPSTONE, FORTRESS, or LIGHTNING lines are exceptional quality, the same if not better than high end seasonic, corsair, etc, and they cost significantly less money. Also all CAPSTONE and LIGHTNING are rated 80PLUS GOLD and the FORTRESS line is 80PLUS Platinum.

I personally run 6 GPU's (5850 and 5870's) off of a 750W NZXT HALE90 (80plus gold) and it doesnt break a sweat. It was expensive and wasn't aware of the rosewill lines at the time, but it works great and it's also single rail.

So back to the thread question.  How do I know which rail is which?   Is there a guide on the back of the PSU?  I've looked at the manual, but really didn't see it, atleast not in a way I recognized. 

Agreed.  I also can't be bothered with load balancing my house, so I run everything from a single 200 amp breaker.  If I draw too much power from an outlet, my house just burns down.  ;)

/sarcasm


Multi-rail power supplies are there for good reason, and they aren't that big of a deal to manage.

Can you post a picture of the PSU's label?

I haven't received it yet.  Supposed to be here this afternoon.  But here it is:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817121070

And here is the manual:
http://kingwin.com/products/cate/power_supplies/manual/max_series/abt_850_1050MM_manual.pdf

Its impossible to know for sure until we see documentation but I have seen power supplies that are multi rail and only two rails contain the pci-e cables. So it may be the pcie are on the two 35 amp rails. which means you might need some molex adapters. Motherboard and cpu usually have their own rail

1. You do not need 1050W for 3 HD5830 (I am assuming it is for a gaming rig with a low powered, preferably undeclocked and undervolted 1-2 core CPU), 750W will be more than enough with headroom for overclocking.
2. Also look at the brand (very important - your PSU that exploded was probably a chinese no-name/piece of crap).

I recommend this website if you're looking for PSU reviews:
http://www.jonnyguru.com/

This is a Kingwin by the way.

Ok I figured it out.  

This PSU has 4 PCI-E 6pins.  

For the other 5830, should I split two 20A rails using molex to PCI-E adapters, or should I just use one of the 20A rails and split it twice?  

I've read the 5830 uses a maximum of 175 Watts.

I want to make it perfectly clear in the first line: The power ratings listed on the rails are a lie. 20A + 20A + 20A + 35A + 35A + 20A = 150A (or 1800W). The rails must in fact share power load to meet the Labels' own criteria of providing 80A across the entire 12V circuit.

I second this fellows suggestion, though it looks like it is too late. You already ordered one of the crappier units on the market, a rebranded out of date throwback:

"It's another Super Flower unit, you're looking at something inline with the Mach1 1000w but less efficient and a cheaper fan.

It shouldn't even do 80+ standard at full load and isn't even modular.

A skip if you're looking for a 1kw unit. "

Why you would want a possible repeat of your previous experience, buying another "6 rail" PSU is beyond me. Again, most of these rails are in actuality shared load (as the total AMPerage of all 12V rails is only 80A). I can't find specs on the PSU, so if I were you I'd hope that the 20A rail is set for the mobo and peripherals, while the 35A rails are for the PCI-E connectors.

If you can cancel your order and return it for a refund though, I'd highly suggest you do that. 3 5830s will run easily on a 750W which you will end up saving money on if you get even a bronze rated supply like http://www.newegg.com/Product/Product.aspx?Item=N82E16817371025 (one of my favs back in the day, probably still decent).

Here's what the label says:

+3.3V & +5V =170W
+3.3V&+5V&+12V=1020W
+12V1~ +12V6=960W (80A)
Max Power = 1050W

Yeah, just send it back to newegg.

For 3x 5830 I would get 850W or more
Probably this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16817151108

or any Corsair, Antec, XFX, or OCZ Z-series/ZX-series unit (none of the other OCZ PSUs though)

eg
http://www.newegg.com/Product/Product.aspx?Item=N82E16817207017
http://www.newegg.com/Product/Product.aspx?Item=N82E16817341044
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139022

Particularly the XFX one above is a good deal.  It's a Seasonic M12D platform (Seasonic rebadge) and the price is ridiculously cheap.

er...  while I certainly advocate using quality PSUs (+1 for the johnnyguru recommendation), why are you suggesting 850W or more for a few 5830s?  ???

That machine isn't going to draw more than 500 watts at the plug unless they are HEAVILY overclocked/overvolted.

My 3x 7950 system can easily pull 625-675 W... 5830 TDP is 170 W x 3 = 510 W, plus another 60-120 W for the board and CPU depending on what he has is 570-630 W.  I always get 20-30% above my intended usage because efficiency is usually highest there and heat production is often less than it would be for a PSU with a lower DC output.  For instance my AX550 with one 6970 on it and a celeron runs much hotter than my OCZ Z-series 850W with the 3x 7950 and a 1055T with 5 disabled cores.

lol..

I have 6 rigs running this exact PSU. and I am able to run 4 gpus on it no problem.

1 GPU on the one PCIe cable (1 cable has 2 pcie power connectors)
1 GPU on the other PCIe cable
1 GPU on the 2 molex cables, place molex to PCIe power adapter on the first molex adapter off the psu
1 GPU on the 2 SATA cables (you'll need SATA to PCIe adapters) Available at meritline. place SATA to PCIe power adapter on the first SATA adapter off the psu

evenly split the hard drives between the 4 molex/sata cables.

Done

Hard/DVD drives get SATA connectors (try spread them out over as many wires as possible)

1x Grahics card gets 2x 6-pin PCI-E

2x Graphics cards get 1 x 6-pin PCI-E + a 1x molex to PCI-E adapter. (Spread them out so they are not all on the same wire)

Ah.  You're using TDP for your calculation.  Keep in mind that you'll never hit the full TDP rating while mining (especially at stock clocks) because some of the card is unused (especially since there is barely any memory usage).  I run a 71Ghash farm.  A good portion of this farm is 5000 series cards.  On one of my rigs (4x 5870s with 2GB of RAM each), I'm drawing 731 watts at the wall.  This means that I'm using about 660 watts DC from the PSU, and the GPUs are overclocked (900mhz/200mhz/1.1v).  This also means that each card is using around 140 watts DC.  They have a TDP of 220 watts.  That's only 63 percent.

His 3x5830 rig isn't going to consume more than 400 watts DC (assuming the card's GPU is overclocked, the memory is underclocked, and it's undervolted).  A properly made 600ish watt PSU (like a 620 watt Seasonic) will easily handle the load and have plenty of room to breathe.  A "cheapo" 1050 watt PSU *really* shouldn't have a hard time with it.

And your name is very fitting.

Ta da!  This is the one thing I needed out of this entire thread and it took two pages to get there.  Thanks man +1  Same for gatorhex, +1

Do PSUs all simply fail if driven too hard? If there some type of breaker or fuse that trips on some models if an over-current situation occurs?

Pictures?

I buy computer power supplies so that I'm drawing at most (during extreme resource utilization) 2/3rd's of their rated wattage.

Overspeced = cooler running/longer life/better efficiency.

OCP (overcurrent protection) is a common feature in PSUs, however it does not function as I think you are implying; it protects components from current spikes.

There are however also overload protectors, which are essentially fuses, that kick in to protect against draw that is too high on most PSUs.

This is why you rarely see an explosive failure in any quality PSU, even at high draws. If you buy a POS like the OP, well... then who knows what will happen. A quality PSU however can be run at it's full rating 24/7 365 days a year, and it won't bitch. Look for PSUs that are rated for their supply continuous rather than peak wattage.

As I mentioned before, I ran a 750W PSU, with ~875W coming from the wall (4 or 5 heavily overclocked 5870s), which was something like 5% above its rated capacity, and it kept ticking even after weeks of this until I swapped it out for a beefier supply.

I suppose the market needs people who refuse to listen to good advice though, or else all the cutrate vendors would go out of business.

It's not that they don't listen, the just can't overcome their learned compulsion to be cheap. Cheap, not thrifty. Always costs them more in the end...

i run 4 HD 5830 Xtreme on my 900Watt PSU with nothing else but an hdd attached. (Overclocked, undervolted (yes)). Cant tell power draw because i dont care, but i estimate 600-650 Watt.
Think of getting an airflow for your PSU that gets it cool air, not that hot stuff from you gpus (because they get really hot). My PSU is not mounted near those gpus or in the same case, so it worked for the preowner for years and still works.

I can see that my choice of PSU (upon the recommendation of multiple established miners on this forum), has clearly upset you.  If I had known you were going to be this distraught I might have asked if you wanted to chip in an extra $50 for me to get a single rail PSU.  So I deeply apologize for upsetting you so deeply.

(By the way, the PSU that assploded was a Corsair.)

Dont' worry about the naysayers.  The PSU will perform fine.  The only problem I had with one Kingwin was the fan failing.  But then again, I've had Corsair, Silverstone, Antec, PCPC, and countless other PSU fans fail too.

I think you meant either 16% above its capacity, or 785W instead of 875:

875 * 100 / 750 = 116.67
785 * 100 / 750 = 104.67

No, I do not mean that; I specifically stated that 875 was wall-draw. There is a difference between power drawn from the wall, and power delivered to the components of your computer, and PSUs are rated for power delivered to components. A gold rated PSU will run at roughly 87%-90% efficiency (depending on the one you purchase) at > 75% load. I believe the one I had, being one of the most superior models on market, was running close to 89% or so (don't recall where I got that now, so I will take it on faith) -

.89 * 875 * 100 / 750 = 103.833333; or roughly 104% give or take.

Responses like this are part of what annoy me about the OPs model choice (I linked him a review by one of the most reputable PSU info sources detailing his PSU as a "must-pass for 1kw+"). People remain willfully ignorant of things that are so important to them as to seek out assistance. I also linked him a model that would perfectly meet his needs, save him money on his power costs, is a far superior build, as rated by experts, not retards on a forum who say "omgz my PSU didnt blow up so that means its awesomez", and cost roughly the same amount as what he purchased.

So to the OP, no, I don't give a crap about your purchase, but your mentality is what bothers me. But, as P.T. barnum said, you'll never go broke under-estimating the intelligence of people. Words to live by.

Ah, thanks for that. I'm not a hardware junkie ;).

In that case, I'm sorry my mentality bothers you.  I hate to be a bother.  Can't we be friends?   ;)

By the way, don't you think the appropriate time to chime in on a psu choice is when they specifically ask for it, in say a thread such as this one posted 2 1/2 weeks ago?  https://bitcointalk.org/index.php?topic=119151.0

Whereas after the psu has been purchased, at that point wouldn't it be best to just answer the question that was asked? 

Thanks for this explanation.

I don't know from the original post if the four-year-old one was the "Kingwin", or if that is what was ordered, what "exploded" (or even what the actual question is), but from the later post of the amperage on a label, an average Kingwin is probably something like this one:

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=155

Note this anomaly they noted:

As promised, the above table shows the 12V rail distribution. What it doesn't show you is that several 12V rails were bridged by solder. 12V1 and 12V2 were combined to one big rail, as were 12V4 and 12V5. Yes, the PCI-E connectors get one big 70A monster rail, almost the whole 12V capacity of the unit.

It looks like that reviewed unit is plain designed stupid. In addition, it shows lots of voltage ripple at high loads, meaning that capacitors are operating near the max of their specs. Throw in cheap Chinese leaky capacitors and that's probably why the original xploded, capacitor plague failure, especially if it ran for a considerable time before dying.

A list of KingWin reviews:
http://www.techpowerup.com/reviewdb/PSUs/Kingwin/

Note that they use names like "Lazer", which would be a cool name in 1983.

This. I have a Rosewill Fortress series 550watt platinum powering a pair of 6950's and an i7-920, and it doesn't even break 80% load. Amazing PSU for the money.