Swedish ASIC miner company kncminer.com

[CYPER]

you should look to run the PSU at 80% of its max rating, because thats where they tent to have the highest power efficiency percentage.   Do not buy a 1250w and run it at 600w for example as this will have a lower efficiency.  if your power draw is around 600w get a 750w.  

I highly recommend the XFX 750 Pro (not core edition)
http://www.scan.co.uk/products/750w-xfx-pro-black-edition-p1-750b-befx-full-modular-80-plus-gold-90-eff-eps-12v-sli-crossfire-1x120?utm_source=google+shopping&utm_medium=cpc&gclid=CKHc8JzJ2roCFVMbtAodNVgAGw

It is badged XFX but is made by seasonic (who also make corsair) but a lot cheaper.  

Unless you intend to upgrade in the future that is. then go for a bigger PSU.

You are mistaken. Highest efficiency is at 50% load.

I assure you 80% is correct.  You may read many reviews of X number of PSUs and you will get a picture that PSUs are most efficient between 50 -70%.  The problem is that these review sites rarely if ever leave the PSU running for 3 or 4 hours.  If you are lucky enough to find a psu review that does test after a long period of time you will see that 80% is the sweet spot on most modern & high quality PSUs.  

If you can send me a link that proves otherwise i would love to read it.  

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Review_Cat&recatnum=13

At one time the efficiency curve was very "curvy" but those days have been gone for a long time.   Today the efficiency curve is very flat the difference between 50% load and 80% load is usually 1% to 2%. 

So buying a super sized power supply to run it at 50% load would save you a whole 1% * 600W * 24 * 365 / 1000 = 52 kWh.  At $0.10 electrical rate the savings would be a staggering $5.20 a year.  Now if you spend $100 more for this larger "have to run at 50% load because some article in 1998 said that" power supply your break even point is roughly 18 years of continual usage.

There is still big difference in efficiency between makes and models ranging from less than 80% to as high as 93%.
My suggestion to anyone is to buy a good quality PSU that has enough wattage to run the miner at 80% usage = less additional noise and heat from the PSU.
And it is not money down the drain, because these products tend to depreciate very slowly and if you buy a good quality one you can expect to sell it for 80% of its price later when you don't need it.

[ElGabo]

For the Psu-s

I have a question. If you have a machine what eats about 700w and you have a 850w Psu, what will you do if somhow we can overclock them and need some margin?

I have a 1500w psu and a lot of big fans to answer this.

But it's only a theory......

[CYPER]

For the Psu-s

I have a question. If you have a machine what eats about 700w and you have a 850w Psu, what will you do if somhow we can overclock them and need some margin?

I have a 1500w psu and a lot of big fans to answer this.

But it's only a theory......

A 850W quality PSU will most probably be enough even for some overclocking if possible, granted a Jupiter uses less than 600W DC power.

[ElGabo]

For the Psu-s

I have a question. If you have a machine what eats about 700w and you have a 850w Psu, what will you do if somhow we can overclock them and need some margin?

I have a 1500w psu and a lot of big fans to answer this.

But it's only a theory......

A 850W quality PSU will most probably be enough even for some overclocking if possible, granted a Jupiter uses less than 600W DC power.

And you'll have a psu at 100% load.

Personally I don't like it. (It's my fault)

[CYPER]

For the Psu-s

I have a question. If you have a machine what eats about 700w and you have a 850w Psu, what will you do if somhow we can overclock them and need some margin?

I have a 1500w psu and a lot of big fans to answer this.

But it's only a theory......

A 850W quality PSU will most probably be enough even for some overclocking if possible, granted a Jupiter uses less than 600W DC power.

And you'll have a psu at 100% load.

Personally I don't like it. (It's my fault)

You just assumed that any future overclock will require additional 250W?
Maybe

If that is the case I can always buy another PSU and use it together with what I have. There is no restrcitions on how many PSU you can use with a single miner as long as it is more than 1 
I have 2 Jupiters each on a CM V850, so if any need arises I can just get a 3rd one and use it for both Jupiters.
The power requirements are quite flexible.

[davewr2013]

For the Psu-s

I have a question. If you have a machine what eats about 700w and you have a 850w Psu, what will you do if somhow we can overclock them and need some margin?

I have a 1500w psu and a lot of big fans to answer this.

But it's only a theory......

A 850W quality PSU will most probably be enough even for some overclocking if possible, granted a Jupiter uses less than 600W DC power.

And you'll have a psu at 100% load.

Personally I don't like it. (It's my fault)

For a KNC Jupiter it could well end up drawing 750 Watts (perhaps a bit more) -- I would recommend a 1000 Watt supply as the minimum.

It would be better with a 1200 Watt capable supply. (Safety margin)

Most engineers like lots of safety margin. In this case the extra cost is cheap insurance.

I would also use a UPS capable of 1000 Watts for 20 minutes (or 1000 - 1200VA if you like) -- with full time AC line filtering as well. Most of  the 1000 Watt level UPS units have AC filtering -- but look for it in the spec.

A lot of places have Solar and Wind turbines contributing the grid -- they cut in and out a lot contributing a lot of electrical noise and over voltage and brown outs -- hence the caution about AC filtering. The power grids are not as stable as they were in pre-green energy days.

fwiw...

Edit: I actually tested a Saturn with a 450Watt Corsair. The 12 Volt lines dropped to 11.5V  With a Corsair GS 800 the 12V lines measure 12.25 volts -- which is fine.

[bobsag3]

For the Psu-s

I have a question. If you have a machine what eats about 700w and you have a 850w Psu, what will you do if somhow we can overclock them and need some margin?

I have a 1500w psu and a lot of big fans to answer this.

But it's only a theory......

A 850W quality PSU will most probably be enough even for some overclocking if possible, granted a Jupiter uses less than 600W DC power.

And you'll have a psu at 100% load.

Personally I don't like it. (It's my fault)

For a KNC Jupiter it could well end up drawing 750 Watts (perhaps a bit more) -- I would recommend a 1000 Watt supply as the minimum.

It would be better with a 1200 Watt capable supply. (Safety margin)

Most engineers like lots of safety margin. In this case the extra cost is cheap insurance.

I would also use a UPS capable of 1000 Watts for 20 minutes (or 1000 - 1200VA if you like) -- with full time AC line filtering as well. Most of  the 1000 Watt level UPS units have AC filtering -- but look for it in the spec.

A lot of places have Solar and Wind turbines contributing the grid -- they cut in and out a lot contributing a lot of electrical noise and over voltage and brown outs -- hence the caution about AC filtering. The power grids are not as stable as they were in pre-green energy days.

fwiw...

Edit: I actually tested a Saturn with a 450Watt Corsair. The 12 Volt lines dropped to 11.5V  With a Corsair GS 800 the 12V lines measure 12.25 volts -- which is fine.

Want to chime in the on the UPS- the pair of 900w UPSs I have only can run a jupiter for 7 minutes.

[ElGabo]

For the Psu-s

I have a question. If you have a machine what eats about 700w and you have a 850w Psu, what will you do if somhow we can overclock them and need some margin?

I have a 1500w psu and a lot of big fans to answer this.

But it's only a theory......

A 850W quality PSU will most probably be enough even for some overclocking if possible, granted a Jupiter uses less than 600W DC power.

And you'll have a psu at 100% load.

Personally I don't like it. (It's my fault)

For a KNC Jupiter it could well end up drawing 750 Watts (perhaps a bit more) -- I would recommend a 1000 Watt supply as the minimum.

It would be better with a 1200 Watt capable supply. (Safety margin)

My first idea was 1200W too...

But there was only a little pirce difference between 1200 or 1500W so margin upon margin. Just for sure. (My simple logic: a bit too much is better than a bit less)

[CYPER]

For a KNC Jupiter it could well end up drawing 750 Watts (perhaps a bit more) -- I would recommend a 1000 Watt supply as the minimum.

It would be better with a 1200 Watt capable supply. (Safety margin)

Most engineers like lots of safety margin. In this case the extra cost is cheap insurance.

You think KNC engineers have made the wrong recommendations with 850W PSU?

[DeathAndTaxes]

For the Psu-s

I have a question. If you have a machine what eats about 700w and you have a 850w Psu, what will you do if somhow we can overclock them and need some margin?

I have a 1500w psu and a lot of big fans to answer this.

But it's only a theory......

A 850W quality PSU will most probably be enough even for some overclocking if possible, granted a Jupiter uses less than 600W DC power.

And you'll have a psu at 100% load.

Personally I don't like it. (It's my fault)

PSU are rated on DC load not AC.  With efficiency around 90% 850W DC would be like 935W AC at the wall.  Nobody anywhere has reported power usage anywhere close to that.   You can only push so much power into the unit.  The chip can only handle so much current, and even if it could use more the DC regulators have a finite capacity (4 @ 40A ea per board). 

To push the clocks higher you need more power you don't need 100% to 200% additional power.  It is like saying I can push 1,000 into a GPU and make it go faster

[davewr2013]

For a KNC Jupiter it could well end up drawing 750 Watts (perhaps a bit more) -- I would recommend a 1000 Watt supply as the minimum.

It would be better with a 1200 Watt capable supply. (Safety margin)

Most engineers like lots of safety margin. In this case the extra cost is cheap insurance.

You think KNC engineers have made the wrong recommendations with 850W PSU?

KNC makes this recommendation:
What specs do I need for the powersupply?
- A power supply (PSU) certified as 80+ Gold (high quality power with low variations).
- for Jupiter models, an 850 Watt PSU with a minimum of four separate PCI-E adaptors (6 pins or 6+2 pin).
- for Saturn models,a 600 Watt PSU with a minimum of two separate PCI-E adaptors (6 pins or 6+2 pins).
- for Mercury models, a 400 Watt PSU with a minimum of one PCI-E adaptor (6 pins or 6+2 pins).

However, as some pointed out the new firmware is causing some units to draw more current (power).

You pays your money -- you takes your choice.

It's your money sunk into those miners -- not mine.

I think that some have pointed out their Saturns are running close to 360-380 Watts -- a Jupiter has two more towers.

Some of us own voltmeters and know how to use them -- so our opinions may be biased by the readings.

Cheers!

[Bitcoinorama]

For a KNC Jupiter it could well end up drawing 750 Watts (perhaps a bit more) -- I would recommend a 1000 Watt supply as the minimum.

It would be better with a 1200 Watt capable supply. (Safety margin)

Most engineers like lots of safety margin. In this case the extra cost is cheap insurance.

You think KNC engineers have made the wrong recommendations with 850W PSU?

KNC makes this recommendation:
What specs do I need for the powersupply?
- A power supply (PSU) certified as 80+ Gold (high quality power with low variations).
- for Jupiter models, an 850 Watt PSU with a minimum of four separate PCI-E adaptors (6 pins or 6+2 pin).
- for Saturn models,a 600 Watt PSU with a minimum of two separate PCI-E adaptors (6 pins or 6+2 pins).
- for Mercury models, a 400 Watt PSU with a minimum of one PCI-E adaptor (6 pins or 6+2 pins).

However, as some pointed out the new firmware is causing some units to draw more current (power).

You pays your money -- you takes your choice.

It's your money sunk into those miners -- not mine.

I think that some have pointed out their Saturns are running close to 360-380 Watts -- a Jupiter has two more towers.

Some of us own voltmeters and know how to use them -- so our opinions may be biased by the readings.

Cheers!

Yes but the initial firmware was drawing around 550 watts at the wall, so you have an entire 300 watts grace. I've also seen those 850s comfortably pull 1000W recently, though I doubt they do so long term!

[davewr2013]

Yes but the initial firmware was drawing around 550 watts at the wall, so you have an entire 300 watts grace.
[/quote]

Fair enough.

What does this version .98.1 cause the unit to draw?

Have you measured or are you guessing? That's all I want to know.

Edit: Another point -- the large units have more capacity (pun intended) to handle "dropouts" of a part cycle. The more expensive higher capacity units also tend to have better characteristics for filtering out spikes.

[Biffa]

Jebus we've had this PSU discussion at least twice before. Just buy the PSU that you want that has at least the minimum spec the manufactrer recommends. Personally I run mine off a 1500W Silverstone connected to a 2200W UPS. But that's what I just had lying around after my CM 850V died.

[Paladin69]

Yes but the initial firmware was drawing around 550 watts at the wall, so you have an entire 300 watts grace.

Fair enough.

What does this version .98.1 cause the unit to draw?

Have you measured or are you guessing? That's all I want to know.

Edit: Another point -- the large units have more capacity (pun intended) to handle "dropouts" of a part cycle. The more expensive higher capacity units also tend to have better characteristics for filtering out spikes.

[/quote]

I am drawing almost 700w with 0.981

[davewr2013]

Yes but the initial firmware was drawing around 550 watts at the wall, so you have an entire 300 watts grace.

Fair enough.

What does this version .98.1 cause the unit to draw?

Have you measured or are you guessing? That's all I want to know.

Edit: Another point -- the large units have more capacity (pun intended) to handle "dropouts" of a part cycle. The more expensive higher capacity units also tend to have better characteristics for filtering out spikes.

I am drawing almost 700w with 0.981
[/quote]

Thank you for that info.

In which case a 1000W or better power supply is a better choice. That means that 30% of the capacity is your safety factor.

My opinion is that a 100 Watt safety factor is a bit light.

Again -- your choice people you own the equipment -- not me.

[DeathAndTaxes]

700W AC is 630W DC.  Power supplies are rating on DC load.  630W load on 850W supply is <80%.

[rampalija]

haveing few 100s wats spare cant do harm ro you power price. Besacuse miner only uses how much it needs

[CYPER]

haveing few 100s wats spare cant do harm ro you power price. Besacuse miner only uses how much it needs

Really?
So then I buy 100W PSU and save electricity 

[davewr2013]

haveing few 100s wats spare cant do harm ro you power price. Besacuse miner only uses how much it needs

Really?
So then I buy 100W PSU and save electricity  

Exactly -- I did not know there were so many electrical engineers and computer designers in the crowd...  

I'm glad I did not work for any of the people wanting to cut corners.... Oh wait -- that's why I don't work as an employee now... Too any experts without the knowledge...

$85 and up for a 800 Watt supply here...
$120 and up for a 1000 Watt supply.

Cheap insurance for a $6000 machine (OK $4500 to $5000 now)...

Happy costs savings folks... Pay your money -- take your choice.