Quote from: DeathAndTaxes on October 11, 2013, 04:32:25 PM

Quote from: Searing on October 11, 2013, 03:44:52 PM

The new asic bords with only 4 VRMs [which were designed to use 8] are using to much power. KNC will release a bug fix for this in next (0.95?) Firmware hopefully arriving in short (Today?) A Jupiter in this Config will use app. 890W. So it can be difficult to start with a 850W ATX. (You can still run them with only 3 boards conected).

What happen to margins on margins. The boards were designed to have 320A of DC regulators (which drop the 12V supply down to the 0.75V used by the chip). Now if BFL cheaped out I could see that but KNC has talked for months and months and month about margins on margins so when they actually get to the finish line and start shipping products at the very last minute they decide to yank out all the margins and run the hardware at close to the theoretical limit and hope everything works.

So the solution to an overheating and overloaded power system is to push the power system even harder. To take 160A (which was designed to be 320A) of capacity and run it at 25% over the redline.

So what is is this negative margins on negative margins now?

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The VRMs are also running over spec with app. 50+ A current each! They probably won't burn, but if you can cool them extra until the new firmware is realeased, do it!!
The Asics are tunning to hot (+70 deg C) as they get app, 0.9V instead of 0.7V as they are supposed to. Cool them as much as you can!!! The Problem is due to the VRMs not working according to spec but KNC will be able to fix it with new firmware (we did our own patch for our miners yesterday).

How about just start shipping the proper 8 VRM design and offer replacements to affected customers (who you shipped underperforming units).

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Easiest fix to cool properly is to provide cool air, belo 20 deg C is a good idea. Open case + big fan will also work.

Yeah that seems like the solution. Open case, giant fan, hardware running overspec, and power consumption through the roof. Throw in the cost of high AC load to maintain 20 deg C cooling. Too bad there is no simpler solution like I don't know ...shipping the product as designed, promised, and sold.

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PS, this does not apply to 8 VRM asic boards. No worries here.

So wouldn't the best solution to ship the boards with 8 VRMS as you initially promised they would?

Hi, I see you quoted me from the KNC forum. Just to get thing straight, I am not from KNC!
We just run a huge bunch of Jupiters in our private mining op. We discovered the problems and let KNC now of them asap.

In the meantime we made our own mod where we adjusted the VRMs voltage offset (by software), the 4 VRM boards are running just as good as the 8 VRM boards and poerconsumtion at wall is below 550W.
All that is needed is the next FW uppdate that will fix this. I talked to KNC development (not support!!!) and they are really rushing this!

No need to ship with 8 vrms as there are no need for them, only need for correct FW! Don´t see any point for them to go back to 4 VRMs when it can be easily adjusted in software.

0.94 has a bug that shuts down parts of the ASICS but never restarts them, thats wy 0.94 performes badly, that will also be in the next FW update.

insuuficent cooling will cause HW errors and shut down cores => bad perfomance

The low performance on some ASICs even if cooling is sufficient comes from another problem they have regarding the internal ASIC communication. As I understand they are on a goood way to fix this. next FW will be better but there will still be more perfomance gains in future FW versions. now they are trying to rush out a 0.95 that will fix the above issues and hopefully give some performance gains and not only solve the above issues! We will se and we all hope for the better.

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