Topic: Sp20 - New to mining (Read 1378 times)

Honestly, theres no reason to spread 2 PSUs over two units. Because when one PSU trips both units will continue 1/2 working, and thus transferring the controller+fan power draw to the other PSU - which will likely trip that one soon after.

1 unit, 1 power supply. If the PSU trips, your settings are too high. watch the asic stats page, you need to set maximum wattage per loop to <180

May I suggest you remove the PSU boxes from there. While its extremely unlikely anything would ever happen, its not worth keeping essentially kindling near to hot surfaces. CX750Ms can get rather hot when 100% loaded, and while they'd never ever get hot enough at normal ambients to ignite something, they can also fail in weird ways. And in that 1/100,000 chance scenario, we want the PSU to destroy itself and turn off in peace.

Yep i think that's exactly what was going on. With a little tweek to the settings with everyones help it seems to be working

Make sure you have one PSU running each pair of power jacks. If you put the two PSUs with one connection on each half, you run the risk of one PSU dwarfing the other and taking too much load. They don't load-balance like properly configured server PSUs so you have to be careful and keep the rails independent.

2 machine using 2 psu's  should work if settings are a tiny bit low   say 1300gh using 700 watts  like klondike_bar mentions.

I think there was some misunderstanding , i'm not running 1 for 1 i have 2 for 2 , if that makes sense. I just think i had them wired incorrectly and even with what i thought was a spread load something kept going off. But it's been stable for a few hours now.

I never said 2 sp20's to 1 psu

I said 6 sp20s to your 6 psu's

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that means 1 psu per 1 sp20

with my settings . 
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I hope you did not damage your psu's or the cables

No , it seems like something was tripping. Strange as both PSU's were still spinning and active.

I was thinking i had maybe too much load one one PSU and in the end i've got like a criss cross power cabling going and with the revised power settings i seem to be happily getting just short of 1400 GH/s out of each of them and the power is quite happy.

It is a bit warm in here though which i know will not be an issue in their final destination.

^wait - why did you arrange them like that? did you cross-link the power supplies to different units so that each is powered by both PSUs? looking at your stats/settings it looks like you set the max wattage to 240w/pcie, which will cause the hardware to start at about a 600W draw and quickly climb up towards a 950W draw. Obviously that will trigger the PSU to turn off

If your power is cheap, you can go to full specs (1600+GH/1100-1200W) using 2 PSUs/miner

or if you want to keep noise/heat down, you can use 1 PSU per SP20, and set your voltage around 0.64 and the wattage limits at 175W/loop to achieve about 1300GH/700W which can be cooled without excessive noise and heat

I've already learnt a few things so hang on in there.

Power for me at home is .0501 KW/h , however these will be going to a farm building where it's about half that. I'm always looking for a way to reduce power and noise and was happy to learn about the firmware upgrade with fan control.

When philipma1957 suggested i can run two SP20's off the power supply i thought i'd give it a go and see what happens.

Initially i didn't do anything except stack them, flip them and power up.

https://dl.dropboxusercontent.com/u/201234/gallery/side_small.jpghttps://dl.dropboxusercontent.com/u/201234/gallery/rear_small.jpg

The units happy sat there for about an hour running at 1.3 or 1.4TH/s .. Couldn't believe it, surely this is the solution to my power concerns.

https://dl.dropboxusercontent.com/u/201234/gallery/1374.jpg
https://dl.dropboxusercontent.com/u/201234/gallery/asic1.jpg

Power consumption is more than acceptable at 1935.7w for 2 units :

https://dl.dropboxusercontent.com/u/201234/gallery/power.jpg


Then i could hear the units start to spin up and down. A quick look at the miner page and the hash rate had halves. A check on the ASIC stats it seems the the power connection is lost on the daisy chain on the units :

https://dl.dropboxusercontent.com/u/201234/gallery/power2.jpg

So i'm guessing it's a balancing act of finding what draw you can handle on 1 PSU before you hit an overload.

I did try the settings show by Philip but then each miner would only output around 550GH/s .

I've now changed the daisy change configuration on the back of the power the try and spread the load across all connections from the PSU's and the SP20.. If i could find a happy medium around 1.3TH/s sharing a power supply then that would be fantastic, even if i have to upgrade to a 1000w PSU as it means i can run another 3 machines without buying any more PSU and Amazon will return these and i get a £100 saving, which is 1/3rd of another miner. However if i can find the right balance using these i have then at £70 a PSU that's quite a saving up front and then on power draw.

Thanks for the continued help all..

If youre running at 1450-1500GH/ea and find thats bordering on too hot and noisy, there's likely no need for having 2x PSU for each. Do you pay for power and how much?

I find these can run on a CS650M (gold) at about 1160GH/600W (about 0.55w/GH). From there to the max speed (about 1650GH), every 100GH speed increase is almost a 100W power increase.   You have 744W of 12V available, a single PSU could probably achieve 1300GH/700W and have a little bit of headroom.

Nice looking setup there.When you move them into your garage the moisture there will dissapear...
I used to keep some antminer S1 (8 of them) and the garage during winter was so hot...

unless your power is free you do not want to run these at 1500 gh.  they are like gpu's they waste a lot of power when pushed.

 I don't know of anyone running a sp20 over 1.8th I have no idea where you think you can run one at 2.1 th

the good thing is those psu's can run 6 sp20's when clocked to 1100gh

I own a Kia Forte it can go 120 mph or 200 kph.  I do not try to power past those numbers.

  I run it at 70 mph it works better.  Here is a suggestion lower your clocks to this setting.  

you will get 3 x 1150 = 3450 gh your power will be 3 x 600 = 1800 gh

right now  you are doing 3 x 1550 = 4650  your power is 3 x 1250 = 3750  

you are driving a kia forte at 120 mph

these are better settings



your asic stats will look like this.  notice my 1 machine uses 600 watts at the wall

Hi all, been lurking for a while and picking up great info so thank you.

Yesterday my 3 SP20's arrived , got to say the service from Spondoolies was fantastic.
After a bit of reading i decided to go for the Corsair CX750M power supplies, 6 of them to be exact. I figured a nice spread of power and if i lost one then the miner wouldn't be totally down.

This is my setup :

https://dl.dropboxusercontent.com/u/201234/gallery/IMG_1351_small.jpg

A bit of in house testing before moving them to the garage and wow is the room hot..

No matter what fan or power configuration i seem to use they are only running at around 1582 each. One unit is sitting at 1.6 but this is still , but sometimes it's less and it's just scraping the +/-10% you would expect.

If i set the power to nuts mode maybe a bit more , but i find it best to have everything set to medium as the extra noise and power drain isn't producing anything more by any viable magnitude.

So my question : Is this a power limit? I'm seeing some people are getting 2.1TH/s from their units. I've set the power settings found in the forum to those and nothing more. To start powering on through to the advertised 1.7TH/s should i be running 2 x 850 or 2 x 1000w PSU ?

Other than that, thank you for the tip on BTC Guild i'm happily mining away with 4.42TH/s