Just to make sure we are on the same page:

Batch 6 was factory set at 600 MHz for 4.06 TH/s with 135 Chips
Batch 8 was factory set at 700 MHz for 4.73 TH/s with 135 Chips

Hence the .25 watts versus .3 watts because of Batch 8 clocked at a higher frequency.

My question is, can I under clock Batch 8 down to 600 MHz and get the same .25 watts efficiency as the Batch 6 at 600 MHz?

we do not speak of bank transfer, we are talking about payment in BTC, which is not any payment for customs, then the seller may also declare a lower value

for example S7 costs $ 1,200 and pay at bitcoin
bitmain could also declare $ 700
This permeterebbe users to pay less money to customs.

but maybe you're financially well, and you do not need to save.
thank you anyway for your time even if you have not voted.

the world becomes a shit for people who do not rebel, and only make us slaves.

What i did was i powerd off everything and the miner was hot like it had overheated waited for it to cooldown and then powerd on the whole thing.
i meen the hashboards where running for about 30 sec whitout the controlboard powerd on and the whole thing like went into overheat mode.. smoke every where you could smell the burned plastic for days. I gusess if i let it runn for like 1 min or more there could prop. be a fire , Whats more intressting is that the PSU was running while the miner was frying itself or what ever, but something was def. Mellting inside it..  i will open up the miner later today and post some pictuers of its hashbords and the miner so you guys can also take a look  maybe , someone have a clue what to do nexst or how to fix this. ? would app. It

Board 1 and 2 was OK and hashing. But board 3 is showing temp 0 and --- --- sometimes 000 000...

Hi Finksy,

Thank you very much for your constructive criticism  Your frankness is much appreciated.  I also appreciate your willingness to contribute HW in Prelude's efforts to determine power efficiency difference between PSU's.  You made very good points about what would probably be the proper way to test PSU efficiency for bitcoin mining applications.  Consistency in HOW the test is performed is extremely important... Making measurements with same meter at same location with same rigs over same period of time.

I hope I did not open up a can of worms.  That was not my intention at all.  I've made too many mistakes in the beginning of my bitcoin mining venture.  I've learned [The hard way] how important it is to make an educated decision about hardware used for mining.  I don't want to continue those mistakes anymore.  I'm hoping this venture will last for many years to come.  So, I'm wanting to make the wisest and most economical decision I can make while growing into the future.

All of the time and energy invested with engineering and design with breakout boards for various PSU's and the commitment to produce these on a relatively large scale for many people by you and J4bberwock is appreciated greatly, Sir!  Thank you both for all you have done and continue to do for the community!

for my English I help with google translator, I am sorry,

I'm pissed off because I do not understand why he said more than they cost,

LOL. Forget it. We're talking about bitmain here.

Your only hope is to have the bank cancel the transfer if you want your $600 back.

Please check PM, I sent message about new order. Tnx.

pump up the volt on the dps, it should workout better & can go either higher or lowers the HW errors for sure.

ah i just saw it's a B8 hmmm but good to see some diff #'s.

i saw on phillipmas post & j4b's post they went higher with higher volts but of course it's the earlier batches.

i'm still happy at stock clocks but after the 90 days, he he he he !

I'm interested in changing Vin to the buck converter to find the maximum efficiency, not in changing Vout to overclock the chips; the LM27402 in this configuration should be able to hold Vout of 10.1 with Vin in lower 11s and it's conceivable to see +/- 1% efficiency over the Vin range 11.6 to 13.3. Numbers / photos soon.

Hi Everyone.


So normally I wouldn't rant about support topics, But I have 2 major issues I have been trying to resolve over the last few days with no joy.

Now I will start by saying bitmain have normally been really good and solve issues quickly, but I don't seem to be getting anything  resolved at the moment so any advice would be much appreciated.

The first issue I have is that my latest S7 that is currently sat in customs has an invoice attached saying the value of the 1x S7 is $30,000 and they want £5000 for the VAT.

Now as far as im aware the S7 I ordered should be valued at $1650 but it seems that there has been some sort of admin error on bitmains side, I did receive an email from bitmain stating that we needed to pay our VAT or the machine would be sent back to them, I advised them of the issue and they sent over the correct invoice to me, but Fedex have request an explanation from bitmain and a copy of the invoice directly from them, so far fedex has not received a response and neither have I.

The next issue im having is with one of our current S7 machine from batch 5 has an issue,  I checked all my machines the other day and noticed a very strong electrical burning smell and noticed 2x hashing boards had gone down.

I assume they have died but cannot check as there is a warranty sticker over the machine that I do not want to touch without the permission from bitmain, So far I have emailed info@ sent a message through zendesk and also messaged zendesk when live support was available and have so far received no response.

I feel a little ignored and for the first time in 2 years im annoyed at the way Bitmain is dealing with my issues, we have easily spent well over $30,000 with them, not much compared to some bigger miners but enough to think they would as least help.

Like I said I have been more than happy with Bitmain products and there support in the past, but feel very ignored at the moment, and any advice would be greatly appreciated.

I have 3 dead boards. I've decided Im going send them to Bitmain. If they can be repaired and if the cost is not too high, I'll get it running in about 3 weeks.

If not, I'll resume my search.

@J4bberwock I'll also ask them to send me back the boards if they can't fix them. We can talk then.

There is probably not much in it, except of course for the greater number of chips favouring the 162 chip systems.
The 162 chip miner with 12v across the 18 Chip string gives a core voltage of 0.667V
The 162 chip miner with 12.2v across the 18 Chip string gives a core voltage of 0.678V
The 135 chip miner with 10.12v (measured by J4bberwock) across the 15 Chip string gives a core voltage of 0.675V

A bigger factor may be if they have been selecting BM1385 chips, which of course we will never know?

Rich

You can buy less, but the price will not change. 5 euro piece+ shipping costs.

On each plate is 8 x VRM, the same with Neptune and Titan VRM.s.
VRM (voltage Regulator Module) is just a different name for DC/DC converter.

 Price of the new VRM is 35 USD, if quantity is 500 pieces.

You can see how much is the Jupiter Boards  eBay price .  US $39.00  .    9 available   /  11 sold

http://www.ebay.com/itm/KNC-Jupiter-ASIC-November-Mother-Board-International-OK-/111759749380?hash=item1a05667104:g:uQ4AAOSwgQ9V5TPQ

I'm looking for 3 working hash boards from either Batch 1,3, 5 or 6 (600 Mhz).

If you have 1 to 3 boards you could sell,  PM me with cost per board.

It should have a warranty no matter where you bought it unless it was from someone who bought from them and sold it as is (basically 2nd hand) but why not try anyways. If all else fails you could try to diagnose and try to repair it yourself if your tech savvy. Its not hard to put a chip back on if that's the issue. If not then pay someone who can or just write it off as a loss and move on (maybe sell the board to at least get something back).

There is no point in changing the voltage on a Batch 6, 8 or 9. They have a Buck Converter built onto the Hash board that controls the voltage sent to the chips. Good news is that at some point I am sure a mod will be available that will enable the Core Voltage to be adjusted.


Rich

It would be great if they do something.... but my gut feeling is that those numbers look very familiar from all sorts of conf files in other miners that do nothing?

Any chance the Batch8 is software controllable? digging around vi SSH (root/admin), found these references:
etc/config/cgminer.conf:    "bitmain-voltage" : "0706"
etc/cgminer.conf.factory:   "bitmain-voltage" : "0725"

seems strange that they are different, yet still necessary to reference. Anyone know what voltage the B8 actually runs at?

I have done some maths on the Digital Pot, which has 32 positions, in combination with the 6K8 to ground & series 12K. So assuming it is a 50K Pot we get.

        Supply V   Core V
Min       8.63        0.58
Mid       9.17        0.61
Max     11.87        0.79


Which would be a very sensible range of core voltages, so may be correct?

Rich

8V would make sense for the sort of voltage you would expect without the shunting effect of the Digital Pot. So this implies that the PIC is being controlled or at least reset by the controller as opposed to it being completely stand alone as I had assumed?