Topic: Swedish ASIC miner company kncminer.com - page 846. (Read 3050071 times)

Do you use the paper clip trick to power on the PSU? If you do, make sure there is a solid/good/tight connection there. If it is not, it could power off the PSU.

The air sucks into those fans (where the Ethernet port is) and expels all the hot air through the rear grill. The back of your rigs, where the hot air expels, isn't pushed up against the wood, right? It assume it is open behind there heating up your house or heating up something.

An interesting test might be to measure the 3.3v rail on the motherboard plug of a working miner that has a jumpered motherboard plug.  Shut down the miner/supply and watch how quickly the 3.3v rail discharges or not - use a digital meter not an old analog multimeter.

But then that would only show the test supply on hand and there are many switching supplies out there.

One way to disprove that element of my theory, 3.3v rail getting stable before the 5v or 12 volt rails might be shown or not by someone with a nice fast sample and hold oscilloscope and a camera.

The ramping of current on the 12v line isn't theory but said by the tech rep from the VRM manufacturer.  When one of two engineers designing a switching-servo-amplifier that I was breadboarding as a technician around 1977 designed the then novel switching scheme while our US company was a division of Kollmorgen, he having gotten his degree from Brooklyn Poly Tech,  the triangle wave which to a comparitor input would see a lowered DC voltage on the other comparitor leg (that voltage the feedback) until the top of the triangle wave was encountered at which point the output would swing from one rail to the other for the duration of the interception.  When the lower voltage (feedback) would reach the triangle wave and the output swing from say zero to full voltage, the controlled voltage would increase raising the feedback voltage level above the triangle.  Typically to maintain an output voltage at some current the comparitor would have the feedback level at some stable level intercepting the triangle wave producing a square wave with the necessary duty cycle.

The triangle wave was produced with a current source charging a capacitor then discharging the capacitor.  Voltage charging a capacitor happens at a changing rate over five time constants.  Current charging a capacitor, or current discharging a capacitor,  will result in a non-curving slope; charge/discharge will give a triangle wave, not an approximation like if you only use the first time constant but a linear charge and discharge.  

That up-ramp of current on the 12v line would follow a straight line, a non-curving slope.  That rise would be dictated by a voltage produced elsewhere by a current source charging a capacitor, that would not  be a filter capacitor.  

There would be an internal filter capacitor on the 3.3v line.

My theory is that the up ramp for the current would be perhaps between 0v and 1v produced using the 3.3v rail because the 3.3v rail would have established itself before the 5 volt rail or the 12 volt rail, and that with no load on the 3.3v rail, e.g. no motherboard in place and a jumper on the motherboard plug, the up-ramp charged capacitor might not be brought back to 0 volts but remain at 1 volt or the full current condition.

i do agree, id rather have a tweaked 28nm now....ah well....if i wanted every single thing the way i like it, i would have started my own company, clearly thats not gonna happen so we depend on knc!

That is one of knc's key selling point for knobtune, but what difference does it make if you can hash exactly the same TH on a well designed 28nm?

Whoever suggested a few weeks back they should have just worked on a better 28nm design rather than 20nm was probably right.

Let's be honest - the only reason knc are doing 20nm is to justify the ridiculous price.

28nm 750gh now is >>>> than 20nm 3-6 months from now.

not 20nm though.....

32 neptunes left - I hope knc deliver in q1 and rain on all these mfs parades.

Sure nice improvments, they come quite late, though. Batch1 BJ customer have paid 50 btc for one unit long time ago. Just saying...

I was just about to order a black arrow x-3 but it seems that batch 1 is sold out and batch 2 won't be shipped until april. Anyone have an idea if it's the same for Knc?

It's Friday 13th, time for something spooky:

https://hashfast.com/hashfast-announces-fastest-bitcoin-mining-chip-in-the-world/

500GH/s on a single chip.

And they expect to get more.

If they can get it up to 750GH/s (i.e. 3TH/s on 4 boards), they will have acheived now what KNC are promising 7 months from now  

Then I would say get a new router.  Honestly even a cheap $30 router by any of the major brands (Dlink, netgear, etc) will have solid DHCP reservation support these days.  Just check the reviews on a networking site before you buy one to make sure it will do what you want it to do.

For example:


Grr..  bitcointalk's image proxy is broke.

Direct link:
http://i.minus.com/jZPw0b7bBMH99.png

I have pointed this out and I agree it doesn't make sense.

The days of rectifying AC into all voltages directly haven't existed for years (probably a decade).  Modern PSU are essentially 12V "engines" with the rest added as legacy support.  This is why if you look at a modern PSU say a 1250W SeaSonic it can delivery 1248W on the 12V rail alone.  All the power is being converted into 12 VDC and then if needed a sub board (and on the SeaSonic it literally is a completely different board) converts some of that 12V to 3.3V, 5V, 5VSB, and -12V if needed.

I am using a SeaSonic 1250W with no issue.   Shutdown is likely over current protection kicking in.

1) The SeaSonic has two PCIe connectors one one cable.  Don't use two on one cable.   You should have 4 connectors plugged into the power supply itself (plus mother board and molex connectors).  That means you will have 8 PCIe connectors use only one from each pair.

2) Make sure the paper clip is making a good connection.  It may sound stupid but you might want to try either a different paperclip or buying a cheap "PSU tester" to ensure you have a good connection.

3) Check the PCIe extension cables.  On one of mine one of the pins was loose.  Loose connection = resistant = higher current to deliver the same power to the ASIC.   Another way to test this is unplug the PCIe extension cables and connect your power supply directly to the ASICs.  I found putting the PSU on the rig lid sitting next to the rig body allows everything to fit.  If you get no trips connected directly and it continues to trip when using the extension cables then one of them likely has a loose pin.

I don't think it's possible for this to be correct. In most (all?) modern ATX PSUs, AC is converted to +12V, and the +12V rail provides the input power to the DC-DC converters that produce the 3.3V and all the other power rails, so it would not be possible for the 3.3V ramp to control the 12V ramp time.

Here is what he had said on the matter.  It is untested so do not take it as gospel.  But in terms of losing a board for a week or more I think I will play it safe.

But before you do that, put the board inside an ESD-safe bag.

I'd still use a small box rather than an envelope, personally, with bubble-wrap inside the box.