Enough Power?

[Intention]

So I more or less made my old gaming PC into a miner with a HIS 5850 but recently there is a sale on 6770's and I can grab one super cheap.  I was curious does the power supply I currently have for it: Enermax ELT500AWT (500Watt Liberty series) have enough power to handle both?  If I have to upgrade then the addition loses it's super cheap value however I thought I'd consult you guys before I put it in and have something explode.

[despoiler]

So I more or less made my old gaming PC into a miner with a HIS 5850 but recently there is a sale on 6770's and I can grab one super cheap.  I was curious does the power supply I currently have for it: Enermax ELT500AWT (500Watt Liberty series) have enough power to handle both?  If I have to upgrade then the addition loses it's super cheap value however I thought I'd consult you guys before I put it in and have something explode.

This is the PSU calc I use.  http://extreme.outervision.com/psucalculatorlite.jsp  Easily the best out there that I have found.

[Intention]

So I more or less made my old gaming PC into a miner with a HIS 5850 but recently there is a sale on 6770's and I can grab one super cheap.  I was curious does the power supply I currently have for it: Enermax ELT500AWT (500Watt Liberty series) have enough power to handle both?  If I have to upgrade then the addition loses it's super cheap value however I thought I'd consult you guys before I put it in and have something explode.

This is the PSU calc I use.  http://extreme.outervision.com/psucalculatorlite.jsp  Easily the best out there that I have found.

Gave it a quick try I ended up with like 411 which seems low for two cards but I think I might give it a try.  It's an old AMD dual core Athlon and I was going to pull the drives and run BAMT off a usb stick which should lower the power usage more.

[P4man]

A quick google reveals your psu only delivers 32A (384W) on the 12V, which is basically all that matters. Thats cutting it REALLY close for a 5850 + 6770 + AMD X2. I wouldnt do it.

[Intention]

A quick google reveals your psu only delivers 32A (384W) on the 12V, which is basically all that matters. Thats cutting it REALLY close for a 5850 + 6770 + AMD X2. I wouldnt do it.

I never really understood how to tell if amps on which rails is enough (or for that fact what's a rail) but I had a sneaking suspicion just that the computer is a few years older that it might not have been enough.  I will heed your advice and not do it but I think I will grab a different power supply with it.

I can get a Thermal Take TR-600 for sub $50 (600watt) and I took a quick look about the amps, 12V1 has 23Amps and 12V2 has 20Amps is it safe to assume that's good?  I know it probably isn't a stellar supply or efficiency rated but I'm just looking to do a cheap upgrade/addition since I cannot afford or have room to setup a proper farm of any sort.

Another one I looked at is the Cooler Master eXtreme Power Plus 600watt it has 18Amps on both 12V rails.

[P4man]

Either of those PSUs should do it. Your existing one might, but like I said, its real close to the spec. Now high quality PSUs tend to be specced at high temperatures, meaning if your ambient temperature is low, you might exceed the rated spec (I have had an antec 500W earthwatt PSU that delivered 600+W without sweating), but you will find more PSUs that struggle to actually achieve what they are specced for. Enermax have a decent reputation, you might get lucky, particularly if you can keep the cpu load low.

If you are not too concerned about power efficiency, and more about cost, you can also use a second cheap/old PSU to power one of the videocards.

[jake262144]

I never really understood how to tell if amps on which rails is enough...

Elementary school science here:
Volts * Amps = Watts,
therefore:
22A * 12V =  264W
30A * 5v = 150W

This PSU of yours has a terrible layout for mining:
First 12V rail provides power for all modular cables and mobo connector whereas the other for the hardwired CPU connectors.
Therefore, if your GPUs are going to draw more power than that measly 264 Watts, you're going out of spec.

Warning, warning: when Hardware Secrets editor tried overloading this particular PSU, it BURNED DOWN on them.
Full review here: http://www.hardwaresecrets.com/article/Enermax-Liberty-DXX-500W-Power-Supply-Review/303/8

When looking for a small (550W) mining-grade power supply, I'd recommend you try this baby: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=225
All this unit's +12V juice goes through just one rail, which could give you up to 530 Watts of power provided the minor rails (5V and 3.3V) aren't loaded.
Here's a review of the 650W and 750W models: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=216
I've been running the XFX 750W PSU for 8 months and have absolutely nothing bad to say about it.

Here is a 10 page long article explaining some of the PSU-fu: http://www.hardwaresecrets.com/article/327
I suggest everyone interested in learning some PSU basics follow this link I posted and familiarize themselves with the basic concepts.
Take the time and you won't burn your PSU, your rig, or your house.
I'll be checking up on this thread and will try to answer any questions.

[P4man]

Warning, warning: when Hardware Secrets editor tried overloading this particular PSU, it BURNED DOWN on them.
Full review here: http://www.hardwaresecrets.com/article/Enermax-Liberty-DXX-500W-Power-Supply-Review/303/8

Good link. But to be fair, they were pulling 48 amps on the 12v rails,  thats 50% over spec and more than the OPs configuration would ever pull.

Edit: in their conclusion they mentioned the PSU is essentially the same as the  Antec Earthwatt I had, although the antec's overload protection does work, unlike the enermax's. On one hand, that makes me more confident it will be able to power a 5850 + 6770. Ive had my antec power two overclocked 5870s and litecoin mining 100W CPU. OTOH, I dont like PSUs burning instead of shutting down.. so Id still look for a replacement.

[jake262144]

Good catch P4 but that should be inconsequential!
Provided the protective circuitry worked correctly, the unit should have seen it was in trouble and should have powered down cleanly.

See my edited previous post for some PSU suggestions.
I'm suggesting the XFX model (which I own) but if you do your research, you'll find other PSUs based on the same Seasonic-designed platform.
Armed with the basics of how PSUs work, you should be able to find even better units, built on some even more recent designs.

[Intention]

Good catch P4 but that should be inconsequential!
Provided the protective circuitry worked correctly, the unit should have seen it was in trouble and should have powered down cleanly.

See my edited previous post for some PSU suggestions.
I'm suggesting the XFX model (which I own) but if you do your research, you'll find other PSUs based on the same Seasonic-designed platform.
Armed with the basics of how PSUs work, you should be able to find even better units, built on some even more recent designs.

Thank you for the link jake I started reading it and will take a look at it again tomorrow since it's getting late but I appreciate the input, at least my house won't burn down since you know I like it and all.

[jake262144]

Take it easy, I was mostly kidding about the house getting burned down

Very few people appreciate how much magic there is to that metal box with wires.
Most go something like "Huh? Is there actually any magic in that sad little gray thing?"

80 PLUS TITANUIM certification has been released for 220V.
It mandates that the PSU does not waste more than 4% power at 50% load. That's 96% efficiency.
Whoever is able to get their design certified, will have to have cast insane amounts of magic putting that PSU together
Link: http://www.plugloadsolutions.com/80PlusPowerSupplies.aspx

[rjk]

80 PLUS TITANUIM certification has been released for 220V.
It mandates that the PSU does not waste more than 4% power at 50% load. That's 96% efficiency.
Whoever is able to get their design certified, will have to have cast insane amounts of magic putting that PSU together
Link: http://www.plugloadsolutions.com/80PlusPowerSupplies.aspx

Wow, such PSUs might be perfect for my 18x 7990 rig, if anyone decides to make them. 18x? Yep - with watercooling, VT-d, and a few virtual machines, it *should* be possible. Take a look at this: http://www.chassis-plans.com/single-board-computer/S6806-backplane.htm

240V is easier to make an efficient PSU out of, but 96% is totally awesome.

Anyone wanna invest?

[bulanula]

80 PLUS TITANUIM certification has been released for 220V.
It mandates that the PSU does not waste more than 4% power at 50% load. That's 96% efficiency.
Whoever is able to get their design certified, will have to have cast insane amounts of magic putting that PSU together
Link: http://www.plugloadsolutions.com/80PlusPowerSupplies.aspx

Wow, such PSUs might be perfect for my 18x 7990 rig, if anyone decides to make them. 18x? Yep - with watercooling, VT-d, and a few virtual machines, it *should* be possible. Take a look at this: http://www.chassis-plans.com/single-board-computer/S6806-backplane.htm

240V is easier to make an efficient PSU out of, but 96% is totally awesome.

Anyone wanna invest?

Funnily enough I investigated these platforms with backplanes but nobody tried it and I don't wanna be the first either

In theory it should make a hell of a mining farm !

[rjk]

Funnily enough I investigated these platforms with backplanes but nobody tried it and I don't wanna be the first either

In theory it should make a hell of a mining farm !

My hang-up is the watercooling - it would be a very complex endeavor. How to properly size the pumps, radiators, manifolds, etc, and do it in such a way as to fit in a standard datacenter rack. Air cooling would be all but impossible if I wanted to fill all the slots. I estimate costs per unit to be just under $20,000 and use approximately 35-40 amps of power continuously at 240 VAC. So it would be rather expensive to start with, and could take a while to return any sort of investment.

[jake262144]

Wow, you're going to have to use radiator surface the size of a football field
Going with so many pumps, water blocks, all that watercooling stuff... I'm afraid even 20k$ might be a low estimate.

[rjk]

Wow, you're going to have to use radiator surface the size of a football field
Going with so many pumps, water blocks, all that watercooling stuff... I'm afraid even 20k$ might be a low estimate.

Well my estimates were based on $650 6990s, $110 waterblocks, a $2000 host computing board, a $650 backplane, and six PSUs hopefully being less than $500 each. The unfortunate issue is that the manufacturers of the waterblocks don't publish technical specs such as flow rate at a certain pressure, recommended pressures, etc. so my numbers might be bad estimates.

However, from my calulations, this radiator should be able to dissipate all the heat from 18x 6990s when used between 0 and 1 Bar of pressure, because it is rated at 10 horsepower heat dissipation at that pressure. Yeah I know it is an oil cooler, but there shouldn't be any reason for it not to work with glycol or similar. The heat dissipation table is on the catalog page at this link.

[bulanula]

Wow, you're going to have to use radiator surface the size of a football field
Going with so many pumps, water blocks, all that watercooling stuff... I'm afraid even 20k$ might be a low estimate.

Well my estimates were based on $650 6990s, $110 waterblocks, a $2000 host computing board, a $650 backplane, and six PSUs hopefully being less than $500 each. The unfortunate issue is that the manufacturers of the waterblocks don't publish technical specs such as flow rate at a certain pressure, recommended pressures, etc. so my numbers might be bad estimates.

However, from my calulations, this radiator should be able to dissipate all the heat from 18x 6990s when used between 0 and 1 Bar of pressure, because it is rated at 10 horsepower heat dissipation at that pressure. Yeah I know it is an oil cooler, but there shouldn't be any reason for it not to work with glycol or similar. The heat dissipation table is on the catalog page at this link.

You already started on the backplane project ? Did you buy a backplane already ?

[rjk]

You already started on the backplane project ? Did you buy a backplane already ?

No, I don't have enough capital. But I am still trying to crunch all the numbers and see whether it could be done. Pie-in-the-sky dreaming I guess.

[DeathAndTaxes]

Wow, such PSUs might be perfect for my 18x 7990 rig, if anyone decides to make them. 18x? Yep - with watercooling, VT-d, and a few virtual machines, it *should* be possible. Take a look at this: http://www.chassis-plans.com/single-board-computer/S6806-backplane.htm

Oh it certainly IS possible but it will end up costing more than equivelent GH using multiple rigs and virtual machines just add more complexity, part failures means losing an entire hashing farm, etc.

What "should" be cheap is a mATX board w/ PCIe extender to another rack full of PCIe expansion slots.  Sadly those are thousands of dollars more than just building a bunch of rigs.

I spent a good amount of time calculating, and pricing, and trying to think outside the box but

CHEAP CPU
CHEAP RAM
USB STICK
MB w/ ENOUGH EXPANSION SLOTS
3 or 4 DUAL GPU CARD
GOLD PSU

is pretty much unbeatable.  5970 or 7990 it isn't going to change the equation.

One way to look at it is.  Excluding GPU and PSU what is the "overhead".

A 3x PCIex16 MB runs $170.  A Sempron $20, Memory $10, USB stick $10
So that cost is $210 for 3 slots = $70 per slot.  Using Dual GPU makes it $35 per GPU.  That doesn't require any expanders.

With expanders you could go cheaper MB w/ 4 PCIe x1 or x16 slots ~ $120. A Sempron $20, Memory $10, USB stick $10, expanders $40
$200 for 4 slots = $50 per slot.  Using Dual GPU that is $25 per GPU

Now AMD drivers limit to 8 GPU so you could go w/ more slots but then you are talking about single GPU so it doesn't really save much $$$.




To be more cost effective an 18 slot backplane would need to be  (excluding PSU + GPU) $70 * 18 = $1260.  You can't find a backplane + SMB for less than $5000.

Even if you wanted some monster radiator to dump 5KW outside it would be cheaper to just build 5 or 6 watercooled rigs w/ no radiator and a fluid-fluid heat exhanger.  Then get a loop to combine connect the heat exchangers w/ larger tubing, powerful pump, and massive radiator.  I am thinking about doing that this summer.  The problem is the capital costs are huge and AC although inefficient is cheap (relatively speaking).

My power load is ~4KW.  So $3500 per year in power.  However AC requires ~30% more power to remove the heat 6 months out of the year so that is $600 per year.  For the benefit of the doubt lets say $800.

Still to waterblock 15 5970 will cost ~$1800.  5 heat exchangers is another $500.  Pumps, resivours, tubing for 5 rigs is ~$1000.  So we are looking at $3300 for the primary loops.  Lets pretend I get parts for secondary loop for free. 

$3300 / $800 per year = 4 years payback.  It just doesn't make economic sense.

[rjk]

Like I said - pie-in-the-sky - but what made me think about it seriously was this: http://www.ebay.com/itm/260836521449 only $650.
I estimated $2000 for the SHB host card because it wouldn't need to be the top-end model with all the latest stuff.