GekkoScience has a new pod miner, just in time for Christmas

[tcj2001]

Pardon my ignorance, I have attached the screen shots of cgminer for both of these units
Compac-f https://imgur.com/Da9dfnc


I believe the WU tells the diff1 and these are very high compared to 18.

Are you expecting the suggest-diff command to have an effect on the Worker Utility?

In your screen shot it looks like your suggest-diff of 500 is being honored.  So that equates to 9.94 shares per minute being submitted to the pool.

What i observed is if I set difficulty too high then no of accepted shares per minute is less compared to the low difficulty setting. So I guess higher the accepted shares per minute mean more chances of calculating/generating best share.
So now I have set difficulty to 1 on both units so that the pool adjust the difficulty to whatever is feasible for the pool, that way I maximize my chances of calculation done per minute by each units.
I may be totaly wrong in my assumption.

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[os2sam]

What i observed is if I set difficulty too high then no of accepted shares per minute is less compared to the low difficulty setting. So I guess higher the accepted shares per minute mean more chances of calculating/generating best share.

Setting your share difficulty has no bearing on your chances of finding a block or generating a better best share.

It's simply a filter used to keep from swamping a pool with diff 1 shares.  Using a higher share difficulty only filters out low diff shares to decrease the amount of pool resources needed to evaluate your shares and decreases the network bandwidth required to submit shares.

In your example of suggest-diff of 500, shares below a diff of 500 are not submitted and shares 500 and above are submitted.

Your share submission of 9.94 shares per minute just means your hashrate estimate by the pool will have more variance than the pools adjusting to 18 shares per minute.  If you remove the suggest-diff then ck solo will adjust for 18 share per minute which would be a difficulty of around 276.

[tcj2001]

What i observed is if I set difficulty too high then no of accepted shares per minute is less compared to the low difficulty setting. So I guess higher the accepted shares per minute mean more chances of calculating/generating best share.

Setting your share difficulty has no bearing on your chances of finding a block or generating a better best share.

It's simply a filter used to keep from swamping a pool with diff 1 shares.  Using a higher share difficulty only filters out low diff shares to decrease the amount of pool resources needed to evaluate your shares and decreases the network bandwidth required to submit shares.

In your example of suggest-diff of 500, shares below a diff of 500 are not submitted and shares 500 and above are submitted.

Your share submission of 9.94 shares per minute just means your hashrate estimate by the pool will have more variance than the pools adjusting to 18 shares per minute.  If you remove the suggest-diff then ck solo will adjust for 18 share per minute which would be a difficulty of around 276.

Thanks making sense now.
How did you calculate diff of 500 equate to 9.94 shares per minute?

[os2sam]

How did you calculate diff of 500 equate to 9.94 shares per minute?

WU:4970/Suggest-diff:500=9.94 shares per minute.

[tcj2001]

New question: Number of chip in miner vs total hash power.
In R909 there are 6 BM1397 chips, so does each chip individually participate in calculating the best share at the same time or the total hash power is used everytime to do the calculation.

[os2sam]

New question: Number of chip in miner vs total hash power.
In R909 there are 6 BM1397 chips, so does each chip individually participate in calculating the best share at the same time or the total hash power is used everytime to do the calculation.

Each Core in each chip is calculating shares.  The total hash rate increases the chances of finding a share that meets or exceeds current difficulty.

[gergar]

What I think can help is make the fan to pull / extract the air use the original as it is stronger than Noctua (Arctic label pointing the PCB will make it to extract --- I checked their specs as I have Noctuas too) and add thermal pads to the bottom heatsinks 1mm @ 13+w/k will have the highest impact in it, those few changes will give you 650@2.5-2.6T stable on a ~120W on stock voltage.

Hm, why do you think the stock fan is stronger? When comparing the specs between the Noctua NF-A8 and the Arctic F8, I see the Noctua better in every discipline. Slightly higher RPM, better airflow and MUCH better static pressure. The latter of which makes it an even better candidate for blowing air into the unit (the original direction).

My bad i checked vs the Noctua R8 (the ones i have with me), I didn’t saw you were using the A8, yes that is better to push but still it is weak, it will do better extracting thought but pushing these fans are quite weak.

having it to push and the original and/or other noctua pull will help, but i not sure how effective will be as it wont be in a close setup “tunnel” but i assume it will help to keep them cooler and accelerate the air causing it to cool a bit more.

[pkspks]

Am I the only one struggling to take these things apart? Any suggestions would be appreciated! I managed to unscrew everything except the screws for PCB standoff and I still can't slide or pop the cover off. Do I also need to unscrew the screws holding the PCB standoff? These screws seem somewhat tighter and didn't want to risk stripping it.

[kano]

Two things:

1) The CompacF mines at a minimum of 16 diff - I've coded it to not go lower.
The R909 miners at a minimum of 64 diff - I've coded to not go lower.
These values are already below what is needed.
People should expect pools to be pissed off at them if they tried to DDoS the pool with lower values.

2) All about worker difficulty: https://kano.is/index.php?k=workdiff

[sidehack]

Am I the only one struggling to take these things apart? Any suggestions would be appreciated! I managed to unscrew everything except the screws for PCB standoff and I still can't slide or pop the cover off. Do I also need to unscrew the screws holding the PCB standoff? These screws seem somewhat tighter and didn't want to risk stripping it.

You would have to flex the case outward at the bottom a little bit to get around the board. If you unscrew the PCB standoffs from the base and slide the whole innards out the front, the case would come free without issue. There's a planned board revision for the next batch that addresses heatsink screws and also ease of [dis]assembly.

[100knot2dae]

@sidehack is there really no thermal pad between the "backplate" heatsink and the PCB board (as mentioned here: https://bitcointalk.org/index.php?topic=5423227.msg61639015#msg61639015)? Was that by intention? If not, what would be the recommended choice from your side in regards to thickness and thermal conductivity of such thermal pad? And would that give some significant cooling benefit at all?

If that makes sense, I am tempted to do that. Unfortunately, I didn't check the heatsink dimensions back then when I replaced the fan. Can you please share these, so that I don't need to unscrew my unit again.

[sidehack]

Heatsink is about 45x70mm

Yes there's no interface between the bottom heatsink and the board. I'm gonna be doing some testing this week on a few potential changes to improve cooling, and underside paste is one of them.

[100knot2dae]

Heatsink is about 45x70mm

Yes there's no interface between the bottom heatsink and the board. I'm gonna be doing some testing this week on a few potential changes to improve cooling, and underside paste is one of them.

Thanks for the info, then I will probably order some thermal pad and do some tests here as well. Actually when touching the bottom heatsink, this really feels just warm, so the cooling should definitely improve with proper heat conduct. (which was in fact already pointed out/confirmed by @gergar)

[n0nce]

Heatsink is about 45x70mm

Yes there's no interface between the bottom heatsink and the board. I'm gonna be doing some testing this week on a few potential changes to improve cooling, and underside paste is one of them.

Paste is a good idea, since there is no conductivity issue on the back of the PCB. Is it possible to remove the back side heatsinks without touching the ones on the front? I'm a little hesitant touching those, since I wouldn't know where to get replacement thermal pads with 20W/mK of thermal conductivity and electrical isolation. In the name of right to repair and keeping these things running for as long as possible, I'd really appreciate if you could release more information on the ones you put into the machines.
I regard them as consumables, just like the fan, which you did a great job of documenting.

For what it's worth, I plan to design a 3D-printable shroud for the back of the unit that lets you route the cables out the top and funnels the air further back where a secondary fan will be placed. Interested to see if it makes any difference.

I love how tinker-friendly this device is, not gonna lie!

[Sledge0001]

Well 2 of the units came in tonight and I am not having much luck with one of em..

1 seems to be spot on from the factory.

The other I am not sure why but it doesn't seem to be coming to life or getting anywhere near the hashrate it should.

I've swapped USB cables, tried a different PSU, tried only 1 R909 but no luck  

Anyone have suggestions?

Code:

cgminer version 4.12.1 - Started: [2023-01-24 19:44:49.046]
--------------------------------------------------------------------------------
 (5s):1.995T (1m):1.802T (5m):653.5G (15m):244.7G (avg):2.037Th/s
 A:55629  R:0  HW:1280  WU:28262.8/m
 Connected to solo.ckpool.org diff 519 with stratum as user
 Block: a7b97cfa...  Diff:37.6T  Started: [19:45:21.343]  Best share: 282K
--------------------------------------------------------------------------------
 [U]SB management [P]ool management [S]ettings [D]isplay options [Q]uit
 0: GSF 10070005: BM1397:06+ 450.00MHz T:450 P:439 (4:2) |  100% WU:^97% | 1.432T / 1.753Th/s WU:24490.1/m
 1: GSF 10070040: BM1397:05+ 450.00MHz T:450 P:109 (5:3) | 21.6% WU: 18% | 367.3G / 270.1Gh/s WU: 3772.7/m

What I do notice is one shows up with 6+ and the other with 5+....

The one with 5+ is not performing in spec.

[gergar]

Heatsink is about 45x70mm

Yes there's no interface between the bottom heatsink and the board. I'm gonna be doing some testing this week on a few potential changes to improve cooling, and underside paste is one of them.

Thanks for the info, then I will probably order some thermal pad and do some tests here as well. Actually when touching the bottom heatsink, this really feels just warm, so the cooling should definitely improve with proper heat conduct. (which was in fact already pointed out/confirmed by @gergar)

thermal conductivity is impacted due to height of thermal path so, don’t exceed 1mm so still stays in a good small size and then you dont need crazy high conductivity pads 20+ and a 13+ will do a great job, 0.5 can be very thin and can get easily damaged so a .75-1mm to my experience is a good choice and still will effectively conduct heat to the heatsink.

[gergar]

Well 2 of the units came in tonight and I am not having much luck with one of em..

1 seems to be spot on from the factory.

The other I am not sure why but it doesn't seem to be coming to life or getting anywhere near the hashrate it should.

I've swapped USB cables, tried a different PSU, tried only 1 R909 but no luck  

Anyone have suggestions?

Code:

cgminer version 4.12.1 - Started: [2023-01-24 19:44:49.046]
--------------------------------------------------------------------------------
 (5s):1.995T (1m):1.802T (5m):653.5G (15m):244.7G (avg):2.037Th/s
 A:55629  R:0  HW:1280  WU:28262.8/m
 Connected to solo.ckpool.org diff 519 with stratum as user
 Block: a7b97cfa...  Diff:37.6T  Started: [19:45:21.343]  Best share: 282K
--------------------------------------------------------------------------------
 [U]SB management [P]ool management [S]ettings [D]isplay options [Q]uit
 0: GSF 10070005: BM1397:06+ 450.00MHz T:450 P:439 (4:2) |  100% WU:^97% | 1.432T / 1.753Th/s WU:24490.1/m
 1: GSF 10070040: BM1397:05+ 450.00MHz T:450 P:109 (5:3) | 21.6% WU: 18% | 367.3G / 270.1Gh/s WU: 3772.7/m

What I do notice is one shows up with 6+ and the other with 5+....

The one with 5+ is not performing in spec.

use Kano new miner.php and get into the gekkochip page check if all 6 are reporting, also at stats if your chips are failing to get set in frequency few causes:
Power not enough - you need a 100w as minimum to run these ones, or they are getting very hot let them cool, and try to push with no to little force the top heatsink and see if move, if it does then the heatsink bolts might got losen with shipping

[sidehack]

Definitely check the heatsinks for tight screws. Reporting 5 chips is problematic; was it doing that from the start, or after running a bit?

[Sledge0001]

Definitely check the heatsinks for tight screws. Reporting 5 chips is problematic; was it doing that from the start, or after running a bit?

Right from the go.

And its 2 r909's on a 750W psu so I know its getting enough powa!

I'll dig into this tomorrow a bit more and check the screws.

UPDATE:
This morning woke up and Zombie mode for the one that was showing on 5+ The other chugging away averaging 1.7+TH

Reboot doesn't seem to help. I'll reach out to the seller and hope they have a spare somewhere since they are sold out.

[100knot2dae]

thermal conductivity is impacted due to height of thermal path so, don’t exceed 1mm so still stays in a good small size and then you dont need crazy high conductivity pads 20+ and a 13+ will do a great job, 0.5 can be very thin and can get easily damaged so a .75-1mm to my experience is a good choice and still will effectively conduct heat to the heatsink.

Thanks, I think I will order a set of these Iceberg pads: https://www.iceberg-thermal.com/product/consumer/thermal-pad/driftice/. 80x40 should be a near to perfect fit, just need to cut the length a little. Hope that I won't mess up with the upper heatsinks' thermal pad when re-screwing the bottom heatsinks...

Actually the unit is running very well at the moment, but I don't think I can leave it now without these pads attached, now that I know of the air gap.

It's like @n0nce has said, this neat device makes you want to tinker with it. 

@sidehack: Would be great if you could share details on the thermal pads used for the upper heatsinks.