Topic: GridSeed 5-chip USB miner voltage mod - page 32. (Read 156988 times)

stock pads are crap and are meant for stock speeds and stock heat. overclocking will produce more heat FACT. ok if your not using sha people SAY that dont get that hot. but damn touch thoose things without the top heatsink on they are HOT!!!!

Right now the heat pads on top of the chips ARE NOT THE PROBLEM. read that again. allow it to digest a bit. beath and now continue.

The gridseed chips have THERMAL VIAs to conduct the heat from the chip TO THE BOTTOM HEATSINK! yes thats right the bottom heatsink. SO to really improve your thermal conduciviy you need to be more concerned about the thermal vias, which are located on the underside of the PCB! remove the screww in rises - yeah thoose things that the screw went into. NOW USING SOMETHING PLASTIC VERY CAREFULLY lever the pcb away from the bottom heat sink. i say carefully as it can and probably is stuck there, from use and the stock thermal pad gettting warm and cooling etc. DO NOT USE METAL.
Now stop re read thoose last two sentences let it sink in. and continue - trust me been there done that, seriuosly screwed up my phone! dont risk it! Metal can and 99.999999% will damage the PCB especially the solder shield underneath it and maybe even create a short you didnt want.

Now once youve removed it toss the stock heat pad - if you want - check the thermal vias, they might need reworking, mine did, i had solder oozing out of one and a noticeable air pocket on the other - i heard the air being pushed out as i was handling it! so check your thermal vias. Highly recommend appling a very generous amount of thermal paste to the thermal vias. this will make sure you have good thermal conducivity there as the paste heats itll flow into the vias creating a good thermal conduct.

Now if your going the route of thermal pad no problem cut it out apply to the underside surface of the PCB and reassemble - take note of the milled out portions in the heatsink and there corresponding alignment to the PCB.
IF your going to cover the whole surface in thermal paste, then cover the serveral exposed copper surfaces - com3, reset switch and a few other, wiht electical insulation tape. you dont want thoose to be short on the heat sink, especially the reset switch!
Apply your paste and reassemble again taking note of the cut outs.

Sorry no photos at the mo. its late and i aint stripping my grid down now, but tomorrow i plan on doing so so hopefully - kids permitting- i can get it stripped and do a few photos.

Or you can wait a few post and see what wolfy has to say - prob no need to change the pads thermal paste crap etc etc.

Pads, or paste your choice id recommend adding paste to the vias though either way. just use care and caution when separating the PCB from the bottom heatsink.

"How much current does the 49.9k mod use?"
Can you say that 20 times over and over without flubbing?  

Nope, ain't gonna disturb my miners mining for nobody right now. Sorry.

I don't know what you're so concerned about. Even 500 Watts aint squat compared to trying to hash at the same rate on GPU's!
What would that come out to? Like 5KW? Just kidding...but you get the point.
It's still cheap by comparison to anything out there right now, as far as I know.
You'll still make profits, regardless.

Next week when I do some more mods for another customer of mine, I'll check current ratings etc. and report back. Next week!
I promise! Okay?

My miners are all running on automatic now. So frikkin cool! I'm seriously impressed!
I'm guessing by my stats, they are doing between 1175 and 1250MHz....
Pool recently showed them runing over 650KHs each recently, dividing the total hash rate of 38.03MHs by 6 = 633khs each! Awesome!
But we all know that isn't possible, right?
Wolfey

I put a 15k resistor (I don't know the tolerance - the local shop only had 3 with close enough values all bent up :-) and I had to try ZiG's mod) on the outer R46 pad and the other common point. https://bitcointalksearch.org/topic/m.6364716  
It is not exactly the value you want to see but I'll report back after it has run 24 hrs or more on sandor's autotune.  It should give you an idea of what to expect.

How much current does the 49.9k mod use?  It's right in between 47k and 52k so is it 26.25 watts?  So maybe 5 watts more than a 47k resistor? Or is it not a linear calculation like that? Too bad you don't have a clamp on ammeter - I'm sure someone using a 49.9k resistor does.  What MHz are you running them at wolfey?  Maybe wait 24 hrs if you just started running sandors autotune cpuminer.   I'll report back on how 48K does in 24 hrs. Autotune changes things a bit I think.  A few extra watts doesn't matter if you only have a few miners but 5 watts x 100 miners = 500 watts per hour!  Note: I only have a few miners that's part of the reason I've run dual mode from the start until now.

Can someone PLEASE stick a 16.9k or 17k 1% resistor on the R46 Pads I just want to see if it will act EXACTLY like the other mods, I do not have my resistors yet to test but I would like to see if this works prior me receiving these things I would love to get the re-assurance.

stock pads are crap and are meant for stock speeds and stock heat. overclocking will produce more heat FACT. ok if your not using sha people SAY that dont get that hot. but damn touch thoose things without the top heatsink on they are HOT!!!!

Right now the heat pads on top of the chips ARE NOT THE PROBLEM. read that again. allow it to digest a bit. beath and now continue.

The gridseed chips have THERMAL VIAs to conduct the heat from the chip TO THE BOTTOM HEATSINK! yes thats right the bottom heatsink. SO to really improve your thermal conduciviy you need to be more concerned about the thermal vias, which are located on the underside of the PCB! remove the screww in rises - yeah thoose things that the screw went into. NOW USING SOMETHING PLASTIC VERY CAREFULLY lever the pcb away from the bottom heat sink. i say carefully as it can and probably is stuck there, from use and the stock thermal pad gettting warm and cooling etc. DO NOT USE METAL.
Now stop re read thoose last two sentences let it sink in. and continue - trust me been there done that, seriuosly screwed up my phone! dont risk it! Metal can and 99.999999% will damage the PCB especially the solder shield underneath it and maybe even create a short you didnt want.

Now once youve removed it toss the stock heat pad - if you want - check the thermal vias, they might need reworking, mine did, i had solder oozing out of one and a noticeable air pocket on the other - i heard the air being pushed out as i was handling it! so check your thermal vias. Highly recommend appling a very generous amount of thermal paste to the thermal vias. this will make sure you have good thermal conducivity there as the paste heats itll flow into the vias creating a good thermal conduct.

Now if your going the route of thermal pad no problem cut it out apply to the underside surface of the PCB and reassemble - take note of the milled out portions in the heatsink and there corresponding alignment to the PCB.
IF your going to cover the whole surface in thermal paste, then cover the serveral exposed copper surfaces - com3, reset switch and a few other, wiht electical insulation tape. you dont want thoose to be short on the heat sink, especially the reset switch!
Apply your paste and reassemble again taking note of the cut outs.

Sorry no photos at the mo. its late and i aint stripping my grid down now, but tomorrow i plan on doing so so hopefully - kids permitting- i can get it stripped and do a few photos.

Or you can wait a few post and see what wolfy has to say - prob no need to change the pads thermal paste crap etc etc.

Pads, or paste your choice id recommend adding paste to the vias though either way. just use care and caution when separating the PCB from the bottom heatsink.

I'll be modding 20 more seeds next week sometime. I'm gonna give Z's mod a try and see what happens. If it's good, I'll say so. If not, I'll say so too
I'm all for simplicity. The KISS rule rules in my universe, as much as possible anyway
I just don't agree with the reasoning behind the mod. Our miners ain't ever gonna see SHA profits again. They be done baby!
Someone want to beat me to it, have at it!
Wolfey

Thank you Zig for the explanation, I think it is a very smart Idea although I will be happy with 510K @ around 20w which is what I am getting with the 49.9k @ 1200mhz at 139k/R52 position.

Can someone PLEASE stick a 16.9k or 17k 1% resistor on the R46 Pads I just want to see if it will act EXACTLY like the other mods, I do not have my resistors yet to test but I would like to see if this works prior me receiving these things I would love to get the re-assurance.

If you're indecisive about 47k or 49.9k/50k you could use a pot, and adjust to your liking - I wouldn't recommend using a pot more than 50k though that way you can't turn it too high.

I would second wolfey's suggestion of using the latest build of cpuminer that Sandor posted in here recently as well.  I never had much luck at all with bfgminer, and cgminer worked well enough for me but the per-chip auto-tuning feature that is in the latest cpuminer is hard to beat.  You can also use a single instance of cpuminer now instead of running multiple instances for multiple gridseeds.

Thanks for the clarification! I think I might try wiring up trim pots up on all of mine if it works good in testing... I like the idea of variable voltage to be able to fine tune so as to be as efficient as possible at around 450-480 hashrate. With that we could find a stable voltage then slowly move down from there. Plust trim pots are quite inexpensive as well. I'll report back once I receive my gridseeds and do some testing. I will post pics / guide if it works well.

powersup - Yes it works.  I copied the positioning of a 1/2 watt resistor you showed in your photo but used a 15k I had on hand. Thanks for the idea.

Thanks ZiG!  I can do this.  I used a cheap battery powered soldering iron.  I measured the voltage as you said before starting to mine.  1.75volts.
I'm testing it using sandors new cpuminer.  Started it up at 1150MHz.   15k + 33k = 48k.  21.46 watts.

Anyone - please post your amps, volts and or watts for all the different resistor values used.  We need some accurate data.  

my measurement results:
vmod1 975MHz to 1000MHz 11.86v, 1.07a, 12.69 watts, 400 kH/s  24hr results
no mod dual mode 750MHz both 11.86v, 4.23a, 50.17 watts, 8.5 Gh/s, 300 kH/s 24hr results
vmod1 dual mode 850MHz both 11.86v, 5.50a, 65.23 watts, 10 Gh/s, 350 kH/s 12hr results
Rmod or ZiGmod 1150MHz (just started and using autotune) 11.86v, 1.81a, 21.46 watts (I'll update with pool results in 24hrs)

This is my oldest pod - note no con2 pins just 2 wires, STM com chip

If you're indecisive about 47k or 49.9k/50k you could use a pot, and adjust to your liking - I wouldn't recommend using a pot more than 50k though that way you can't turn it too high.

I would second wolfey's suggestion of using the latest build of cpuminer that Sandor posted in here recently as well.  I never had much luck at all with bfgminer, and cgminer worked well enough for me but the per-chip auto-tuning feature that is in the latest cpuminer is hard to beat.  You can also use a single instance of cpuminer now instead of running multiple instances for multiple gridseeds.

So I had a go at the ZiG mod since I had some 16K resistors laying around.  All seemed good, i check continuity, and resistance at the regulator leg was 49K so electrically everything looked fine.  However when I plugged the unit in and tried hashing the red LED started flickering maybe at about 20-40hz, then started a flickering / stop cycle about every 3 seconds.

So has anyone tried this Mod and confirmed it worked? does the resistor need to be a 17K?  I would have thought 1K difference wouldn't have mattered. Maybe I have missed something?  

Note: miner worked fine once I removed the resistor and re-bridged R46 pads.  I also did the R139 mod with a 47K resistor and it also worked.

I might have to change to 49.9k from 47k. The power draw is pretty significant... At least 12~ extra watts on each gridseed... But besides that running extremely well and stable

Hi, I'm a little bit shocked!
How in the world did you get stuck using 47k on your mods? 49.9k is the optimum value for least power usage and maximum hash rate with extremely minimum / nearly 0 HW errors?
If you want to see how it's done, look up my posts on here via Search. You can start here https://bitcointalksearch.org/topic/m.6098563 to see how it's done if you don't already know, which you probably do
Also, unless you're not using Windows 7 32 or 64 bit, you can use cpuminer which is the best and most stable and easiest mining program to use as well as the most profitable at the pool!
I believe if you are getting any HW errors, like a lot, it's due in part to using the 47k and bfgminer.
If you can and are willing, I suggest upgrading to the 49.9k or 50k is okay too and change over to cpuminer using the STM virtual comm port drivers and a good USB hub.
You can also covert do my 5V USB fan mod while you're at it. It will run ultra quiet while soaking the cooling fins with enough air to keep them running at room temperature.
Good luck in what ever you decide!

Thanks for all the help. I have now modded 10 with the 47k resistor. I have them all working and have each set to the lowest frequency that gives the least HW errors for each one using BFGminer PR3.
I think all is working bout as good as I can make them. Each one is running about 470khs.

Now, all that I would like to do is set up BFGminer to run in CGwatcher like i use for my GPUs.

Has anyone done this? I think it could be done, except I have no idea how to setup the Conf file.

Does anybody have an example Conf for BFGminer to run in CGwatcher that shows how to setup for multiple Gridseeds using the ID of the gridseed and the frequency for it?

Thanks!

Yeah, Gridseed and Dualminers are PITA...  You should put Your serial numbers instead. BFGminer versions are still experimental, BTW pr3 is more stable for me than clean-version. I'm using CGwatcher for running BFGminer because of crashing and unsuccessfull starts You are experiencing too. Here is my command line with my serial numbers and my serial ports, so You can't just copy/paste the line:
I'm using also standard bfgminer.conf with pools definitions.

wow guys you are genious.!
cpuminer was a little a pain in the ass to configure the script and run it as root and so on... but! It works perfectly.
Cpuminer even adjusts pods to their own specific best frequency, what a charm i love it.!

Thanks a lot all.

stock pads are crap and are meant for stock speeds and stock heat. overclocking will produce more heat FACT. ok if your not using sha people SAY that dont get that hot. but damn touch thoose things without the top heatsink on they are HOT!!!!

Right now the heat pads on top of the chips ARE NOT THE PROBLEM. read that again. allow it to digest a bit. beath and now continue.

The gridseed chips have THERMAL VIAs to conduct the heat from the chip TO THE BOTTOM HEATSINK! yes thats right the bottom heatsink. SO to really improve your thermal conduciviy you need to be more concerned about the thermal vias, which are located on the underside of the PCB! remove the screww in rises - yeah thoose things that the screw went into. NOW USING SOMETHING PLASTIC VERY CAREFULLY lever the pcb away from the bottom heat sink. i say carefully as it can and probably is stuck there, from use and the stock thermal pad gettting warm and cooling etc. DO NOT USE METAL.
Now stop re read thoose last two sentences let it sink in. and continue - trust me been there done that, seriuosly screwed up my phone! dont risk it! Metal can and 99.999999% will damage the PCB especially the solder shield underneath it and maybe even create a short you didnt want.

Now once youve removed it toss the stock heat pad - if you want - check the thermal vias, they might need reworking, mine did, i had solder oozing out of one and a noticeable air pocket on the other - i heard the air being pushed out as i was handling it! so check your thermal vias. Highly recommend appling a very generous amount of thermal paste to the thermal vias. this will make sure you have good thermal conducivity there as the paste heats itll flow into the vias creating a good thermal conduct.

Now if your going the route of thermal pad no problem cut it out apply to the underside surface of the PCB and reassemble - take note of the milled out portions in the heatsink and there corresponding alignment to the PCB.
IF your going to cover the whole surface in thermal paste, then cover the serveral exposed copper surfaces - com3, reset switch and a few other, wiht electical insulation tape. you dont want thoose to be short on the heat sink, especially the reset switch!
Apply your paste and reassemble again taking note of the cut outs.

Sorry no photos at the mo. its late and i aint stripping my grid down now, but tomorrow i plan on doing so so hopefully - kids permitting- i can get it stripped and do a few photos.

Or you can wait a few post and see what wolfy has to say - prob no need to change the pads thermal paste crap etc etc.

Pads, or paste your choice id recommend adding paste to the vias though either way. just use care and caution when separating the PCB from the bottom heatsink.