LOL. I tried it on my oldest S9 and once I cut the blue wires, the rear fan ran at full RPM and the front fan at 1320 RMP (I assume that was the minimum RPM). I got this early S9 used, so it's possible that those are not the original factory fans.

I think the simplest way to make these older S9s cooler is to replace the fans with the new ones Bitmain uses on the newest S9s... they seem to be much more efficient.

The one side effect of my experiment that may be useful info for others as well: I confirmed that the front fan has the lower RPM. At least on this specific miner... I have several different generations of them so I may check the others as well, but I assume this should be consistent.

Thanks - unfortunately, the specs for these fans are nowhere to be found... So I guess it's testing time.

I've read posts about manually setting the fan speed to 100% but it seems complicated with a lot of uncertainties so I'd rather go the hardware route.

How about the voltage in? Is my assumption correct that since the fans are controlled with PWM, the input voltage should be constant (always the full 12V)?

Thanks for the info! Good to know. I know they have different fans, but I don't know yet which one is faster (can't find the specs for their fans - mine have NIDEC UltraFlo W12E12BS11B5-57 on the front and NIDEC UltraFlo W12E12BS11B5-07 on the back) and the UI doesn't tell you which one is front and which one is back.

It's too hot where I am and I'm trying to cool the miners as much as possible. Noticed that my old S9s (with the Delta fans) don't run the fans at full RPM even when the chip temps go over 100C. So I want to hack the miner to have the fans run at full speed all the time - I just want to make sure I understand what I'm doing.

I'm not an expert of fans, just trying to figure this out. Since these are 4 wire fans, I assume black = ground, red = input voltage, yellow = PWN (tach) out, blue = PWM input (speed control).

What I'm not sure about:

1. If I simply cut the blue wire, the fans should run at full RPM all the time, and since the miner will still receive the PWM signal from the fans, it will operate normally (won't assume fan failure and stop mining). Is this correct?

2. As the S9 uses PWM speed control, I also assume that the fan receives the full 12V input voltage on the red wire from the control board all the time, i.e. voltage is NOT used to control fan speed. If this is true, then ideas I heard about connecting the fans directly to 12V from the power supply should make no difference and this is unnecessary. Is this correct?

Thank you. Actually, the front and back fans are different (different model/part numbers). I don't think swapping them or replacing one with the wrong part number (as long as they move enough air) will kill the miner but may be non-optimal.

I know this is an old thread, but found it looking for info on the fans. Do you know how it works specifically for the S9? Which fan needs to be faster - the front or the rear one?

I noticed the different fan speeds, so I assume the reason is to create either negative or positive pressure inside the miner, I'm just not sure which one. Also not sure if they are controlling the fans separately to create the different RPMs or together, and let the different RPM ratings of the front and back fans take care of the pressure difference.

Any insight into this would be appreciated.

Ahm... both fans blow in the same direction (they have to...) so switching the front and back fans would NOT result in one of the fans blowing the wrong way. All fans blow towards the side which has the label. E.g. if you are looking at the front of the miner, you will see the label on the fan and it will blow towards you. The back fan is ALMOST the same type (there is a slight difference) but it also blows towards the direction of the label, that's why you don't see a label on the back fan (it is on the inside, facing towards the guts of the miner).

If a fan blows in the wrong direction, remove it, turn it around, screw it back on, and it will blow in the right direction.

For those interested in the details, the latest S9s have slightly different fans front and back. I have no idea WHAT the difference is, but the front fan is NIDEC UltraFlo W12E12BS11B5-57 and the back one is NIDEC UltraFlo W12E12BS11B5-07 (note the last two digits). Both are rated 1.65 Amps and I see no visible difference between them. But if they took the effort to install two different fans in each unit (which means more complicated logistics), I'm sure they have a good reason for it. I can't find specs for the fans anywhere. If anyone has any info (or even a theory) about the reason for the different fans, I'm curious. Maybe different RPM at the same voltage to make it possible to feed them the same voltage and still maintain the slight pressure difference?

I have a mix of old (fixed 600MHz) and new (autotune) S9s.

Outside peak temps are in the 28-30 celsius (83-86 F) here. I was considering AC but with the added power consumption, mining would be unprofitable.

My old S9s are running around 100-105 C (with a LOT of ventilation), the new ones around 82-88 C. A huge difference.

I'll replace the fans (Delta - 4800 RMP) on the old ones with the same fans the new S9s come with (Nidec UltraFlo - 6000 RPM). I'm hoping that it's only the fan and not the firmware, i.e. if I install the new fans, they will run faster with the old firmware.

Does anyone have any experience with this?

Just to correct one thing: It has different fans front and back. I have no idea WHAT the difference is, but the front fan is NIDEC UltraFlo W12E12BS11B5-57 and the back one is NIDEC UltraFlo W12E12BS11B5-07. Both are rated 1.65 Amps and I see no visible difference between them. But if they took the effort to install two different fans in each unit (which means more complicated logistics), I'm sure they have a good reason for it. I can't find specs for the fans anywhere. If anyone has any info (or even a theory) about the reason for the different fans, I'm curious.

I just know that my newer S9s that came with these fans run as much as 20 (!!!) degrees C cooler than the old ones I have with the Delta fans.

My old ones with the Delta fans seem to max out at 4800RPM, I have seen the Nidec fans go up to 6000. I wonder if this is only the fans themselves, or maybe the new firmware is more aggressive in keeping the miner cool?

I have a spare hashing board and I tried to fire it up today as one went bad in one of my S9s. It didn't seem to work so I tried only that one hashing board (with all the others disconnected) and I get what you can see here:

https://www.dropbox.com/s/2sbe5lv6rt2p7lp/28693795_1799031853441185_1686200933_o.jpg?dl=0

I tried everything I could think of (firmware update on the controller, different power supplies, restarting, resetting, just waiting and letting it run for two hours...) but nothing works. Is this a bad hashing board? Or is it possible that it's not compatible with my (newer) S9s?

The hashing board is March 2017, so it should be auto tune (it has a sticker with "L1" on it). The controller is version 1.2 from January 2018, with the latest firmware.

The red LED on the hashing board is initially on when I turn the miner on, but then it goes off and never turns on again (until I restart the miner).

Website is back online for me.

I'm also in EU and also see some problems. When I try to open the website I get a 502 (bad gateway) error. My miners seem to hash but can't see what's happening on multipool.us. Will wait it out, assuming that hashing works and it's just the website that's down, but if it doesn't get fixed in a few hours, I'm moving my miners elsewhere.

KIND OF related to this topic (Antminers breaking and then hacking them...):

I didn't realize until now that different versions of the S9 and their hashing boards MAY not be interchangeable due to the fixed frequency vs. auto tune versions, as well as other minor changes.

I searched all over the net to try to figure out the version history of the S9, and what's compatible and what isn't but I came up empty.

Does anyone know how the different versions of the S9 control boards and the hashing boards match up? E.g. my S9s are version 1.6. and I just bought a version 3.75 hashing board to replace a failed one, but realizing my ignorance I thought I would find out if they are compatible before I drop in the new hashing board.

I think this info (like a compatibility chart) would be very useful for anyone who needs to replace a hashing board or a control board. They come up for sale on eBay every once in a while but it's better to be sure in advance if what you are buying will actually work...

Any words of wisdom on this would be greatly appreciated.

Hi,

Newbie questions

I'm on a jtoomimnet p2pool node with 32 TH/s. Node hash rate varies, but at the moment I'm contributing pretty much 60-90% of the hash on that node, depending on the time of day - it's pretty much me at this point, with someone else joining in and dropping out at times. The other person already has some shares, amounting to about 0.03 BTS, I have none. Node DOA is under 2% (currently 1.46), efficiency is 97.3%, share difficulty is 1520000. I'm new to p2pool and trying to understand the differences between a regular pool and p2pool. I did read up, but couldn't find answers to these questions:

1. "Expected time to share (this node)" shows around 3 minutes. I have been on the node for about 6 hours, and I have no shares yet. I thought that the concept was that at the hash rate the node is going, if I'm providing pretty much all the hash, the number of shares I receive should be close to what's predicted, i.e I should get a share every few minutes. What am I missing...?

2. I'm trying to understand the difference between a regular pool and p2pool. If I am hashing at p2pool but receive no shares (as is the situation currently) does that mean that the hash I contributed thus far will give me no payout whatsoever if at the time of a block being found I have no shares? So, is it more similar to a shared solo mining than a regular pool in that in a regular pool, any contribution will result in a payout when a block is found, even if ever so small, but in p2pool, if I have no shares, I may have contributed hash to the pool but no shares to me means I get nothing if a block is found by the pool?

3. If I drop off p2pool for a few days (while having no shares yet) and then go back, do I start over from scratch? Or the hashing I contributed earlier makes a difference?

4. One of the stats show this: "Total: 682 (Orphan: 41, Dead: 9)". Is this the number of shares to this node? Is it since the last block was found, i.e. it shows the current shares of this node towards the next block when it's found by the pool? It went from 660 to 682 since I have been on the node, and while I seem to be the biggest fish on the node since I joined in, I haven's received any of the 22 new shares created since I have been on. Again, what am I missing...? UPDATE: I have been the only one on the node for the last hour or so, contributing 100% of the hash. During this hour, the shares to the node went up by 3, but I still don’t have any. Confused... 

Sorry for the newbie questions - I did search first but I couldn't find direct answers to these questions.

I understand and it makes complete sense. I didn't know that the payment was nearly instant, so understanding that makes any other display of result superfluous indeed.

Thank you very much for the quick and helpful reply!

Please excuse my newbie question - I've been using pools for a while but I am new to solo mining... I searched but I couldn't find an answer anywhere:

If I mine on solo.ckpool.org, how do I find out if I found a block? Is there any way to find out/get notified if you found a block other than the payment (eventually) arriving in your wallet? That seems weird given that the information (I suppose) should be available to the operator of the pool, it is also shown (as statistics) on blocktrail.com, but it seems like it is not being shown anywhere to the users mining on ckpool. All I can see is the (very basic) stats of the ongoing hash, but not the result (if any).

Am I missing something?