GridSeed 5-chip USB miner voltage mod

[RowanX]

Anyone in the UK willling to mod my 2 gridseeds?   I am in Kingston upon Thames FWIW.

[pandaisftw]

A new run with 2 more modded.
The two from the last run are also included.


I clocked down the bad units, which where havin to much hardware errors, to see where they stabilize.
It looks like as it has nothing to do with the new units itself, as the HW Errors also occured at another unit(one of the dark gold units).

In my oppinion the benefit of tweaking the PLL Voltage, if its even is possible to achieve positive results by doing this, wont be significantly better.
Trying to regulate a system, while you do not even know in which direction, cant bring you any further. It is just like playing lotto and thats something i wont bring in here.
There is not even one guys here, who actually can proof, that his change in PLL voltage, actually brought him any advantage.
It's just ppl. saying, that they assume, that it must be done, if you have done the resistor change. Thats not science, thats not reliable it is an assumption.
All PLL tweakings i have done so far, brought me bad resulst. So for now on i just call it bullshit and advice everyone not to play with PLL voltage.

Some user wrote me that he thinks, that the mod is not stable, because it has to much HW Errors.
I gave him credit for the fact that he recognized correctly, that the Hashrate(e.g. mhz) which the device was running on wasnt "stable".
And said yes: There are units where you need to go down with the frequency. till its "stable" again.
But that has nothing to do with the mod itself.
It's like the 950mhz mod. There are units which are running fine with 950mhz and there are units which are only able to run at 900-913mhz.
But still are there a lot of ppl. doing the mod because it still brings you more hashrate than 850mhz or 888mhz.
Also if the unit is a bad one and is only stable at 900mhz (with the mod) it must be that it throws also hws at the stock of 850mhz. All what the mod does is increase the range in where your units operate in.
A unit which runs bad even at stock clocks will also run bad on a higher clock compared to good units and thats nothing you can change.
But lets say you clock a bad unit from 850mhz to 1100mhz and the HWs stay the same, it will be still an increase of 30%.
Independant if its a good or a bad unit.

Very nice. Can you specify what mod(s) you did? Also, are you using the stock fan that came with the unit or some other form of cooling? What is the power draw?

Thanks,
Pandaisftw

[wolfey2014]

I have done the 3 mods on 2 of my pods and seen some benefit locally and pool side.  I do find that the choice of pool for testing is important as these multi-coin pools really have poor stratum results.  They toss all different kinds of rejected shares upon switching coins.  I would suggest for testing mod stability to use a sole coin pool as that has given me better numbers. 

Currently running at 1050Mhz stable and I do not have the PLL down to 0.94 yet. Looks like there is more room in these units.

Which 3 mods have you done, specifically? The two jumpers and resistor change to 38k?
thx!

[Dirt9000]

i wish i could get this done in canada! Wow. almost 140 khash over stock tuning. very nice!

[Reggie0]

@SVK:
Thank you.
It should be this repository: https://github.com/girnyau/cgminer-gc3355 and i found it in this thread: https://bitcointalk.org/index.php?topic=477709.msg5752544#msg5752544

Girnyau's cgminer supports per chip statistics and per chip frequency settings:

--gridseed-options per_chip_stats=1,freq=888 --gridseed-freq 8D74488A4949=900:888:1000:925:950,8D96227B5449=900:875:1015:975:813

[CryptKeeper]

The mods I made to one of my pods using a slightly modified version of Sandor's idea on page 6 are still working and stable at 1000MHz.
No pencil mod. No PLL voltage adjustment. It has been left at the factory setting of 1.091V
The change I made was to change out C34 from 10nf to 100nf. This also yields virtually no HW errors at 1000MHz.
The other 3 mods, resistor change out to 38k 5% from 36k and the two jumpers on page 14 are still in place.
I haven't heard of anyone bricking their pod 'yet' by adjusting PLL voltage or core voltage either, for that matter and they have been set all over the place + and -! Hopefully no one will, either!
Still, so far, so good.
I am very curious and excited to see what mods nemercry has come up with to achieve the results he has been talking about.

Are you sure about C34? I have spotted it on your board picture and it seems to me that it's empty.

[CryptKeeper]

I have a treat for all of you. I compiled for Windows girnyau's gridseed fork of cgminer that includes the fine-grain freq settings and freq-per-device settings.

Find it here: http://1drv.ms/1kKPsP2

Please excuse the hasty readme file, I wanted to share ASAP.

(Typical "be careful, unverified binary here" warning. Virus scan it if you want, I know it's clean.)

Feel free to donate to: 1AvazUbrKwY8wuxNMGFtt5KqGW8WXdx4JB

Cheers and enjoy.

Thanks, I have donated a little to you.

Keep up the good work!

[wolfey2014]

The mods I made to one of my pods using a slightly modified version of Sandor's idea on page 6 are still working and stable at 1000MHz.
No pencil mod. No PLL voltage adjustment. It has been left at the factory setting of 1.091V
The change I made was to change out C34 from 10nf to 100nf. This also yields virtually no HW errors at 1000MHz.
The other 3 mods, resistor change out to 38k 5% from 36k and the two jumpers on page 14 are still in place.
I haven't heard of anyone bricking their pod 'yet' by adjusting PLL voltage or core voltage either, for that matter and they have been set all over the place + and -! Hopefully no one will, either!
Still, so far, so good.
I am very curious and excited to see what mods nemercry has come up with to achieve the results he has been talking about.

Are you sure about C34? I have spotted it on your board picture and it seems to me that it's empty.

Sorry for the error.
You are right. It is C36, not C34. Blurry images don't help much.
Thanks for picking up on that.
But I'm working on another mod idea now so......more later, if/when.

[CryptKeeper]

The mods I made to one of my pods using a slightly modified version of Sandor's idea on page 6 are still working and stable at 1000MHz.
No pencil mod. No PLL voltage adjustment. It has been left at the factory setting of 1.091V
The change I made was to change out C34 from 10nf to 100nf. This also yields virtually no HW errors at 1000MHz.
The other 3 mods, resistor change out to 38k 5% from 36k and the two jumpers on page 14 are still in place.
I haven't heard of anyone bricking their pod 'yet' by adjusting PLL voltage or core voltage either, for that matter and they have been set all over the place + and -! Hopefully no one will, either!
Still, so far, so good.
I am very curious and excited to see what mods nemercry has come up with to achieve the results he has been talking about.

Are you sure about C34? I have spotted it on your board picture and it seems to me that it's empty.

Sorry for the error.
You are right. It is C36, not C34. Blurry images don't help much.
Thanks for picking up on that.
But I'm working on another mod idea now so......more later, if/when.

OK, I have 5 miners to mod, but have to wait until the weekend.

If you are not sure about your mod, I'll start with the two bridges and the fan!

[nemercry]

As we are currently doing a clearance sale(care this is advertising), we will make our version of the mod public domain.

It will be posted wednesday 02.04.2014, including a picture of the details.

[nemercry]

As we are currently doing a clearance sale(care this is advertising), we will make our version of the mod public domain.

Is your mod any different from the one in the first post?

Depends on where you draw the line. In the end there is only one way to modify the voltages(e.g. what we all call modding). But there are different ways to reach this.
I personally think it is the most time efficient modification you can do.

[wolfey2014]

The mods I made to one of my pods using a slightly modified version of Sandor's idea on page 6 are still working and stable at 1000MHz.
No pencil mod. No PLL voltage adjustment. It has been left at the factory setting of 1.091V
The change I made was to change out C34 from 10nf to 100nf. This also yields virtually no HW errors at 1000MHz.
The other 3 mods, resistor change out to 38k 5% from 36k and the two jumpers on page 14 are still in place.
I haven't heard of anyone bricking their pod 'yet' by adjusting PLL voltage or core voltage either, for that matter and they have been set all over the place + and -! Hopefully no one will, either!
Still, so far, so good.
I am very curious and excited to see what mods nemercry has come up with to achieve the results he has been talking about.

Are you sure about C34? I have spotted it on your board picture and it seems to me that it's empty.

Sorry for the error.
You are right. It is C36, not C34. Blurry images don't help much.
Thanks for picking up on that.
But I'm working on another mod idea now so......more later, if/when.

OK, I have 5 miners to mod, but have to wait until the weekend.

If you are not sure about your mod, I'll start with the two bridges and the fan!

Oh, I am sure about my current mod. It's been working fine for over a week now.
But there may be a simpler and better way to get higher stable clock / hash rates.
I'm looking into it now. I'll keep you posted.
I'm still doing mods for anyone who cannot do it themselves. PM me for details. I'm located in EUS.

[wolfey2014]

As we are currently doing a clearance sale(care this is advertising), we will make our version of the mod public domain.

Is your mod any different from the one in the first post?

Here is the mod I believe to be the simplest of them all thus far.
I found this after a bit of investigation and I have also just confirmed that it's the mod that nemercry has been talking about, testing and providing pics of for days.
I have not tried this mod yet but I intend to do so asap.

*********************************************************

*********************************************************
A regular 1/8W to 1/4W 1% to 5% axial resistor will work too. Try to shoot for 1% tolerance though.
And as usual, try it at your own risk and expense.
If you'd like me to make the mod for you, let me know via PM. I am located in the EUS.

[RowanX]

FWIW, I recently switched from 850mhz to 875mhz on my vanilla Gridseed unit... and I'm actually getting less HW errors reported in cgminer. Update: actually its about the same if not more, although for the first 12 hours or so there were no HW errors at all.

[nemercry]

As we are currently doing a clearance sale(care this is advertising), we will make our version of the mod public domain.

Is your mod any different from the one in the first post?

Here is the mod I believe to be the simplest of them all thus far.
I found this after a bit of investigation and I have also just confirmed that it's the mod that nemercry has been talking about, testing and providing pics of for days.
I have not tried this mod yet but I intend to do so asap.

*********************************************************

*********************************************************
A regular 1/8W to 1/4W 1% to 5% axial resistor will work too. Try to shoot for 1% tolerance though.
And as usual, try it at your own risk and expense.
If you'd like me to make the mod for you, let me know via PM. I am located in the EUS.

And there you go wolfey.
Yep that is actually the mod how we are doing it.

[nemercry]

As wolfey just found my imgur repository, there it is:
Thats the mod we are using.


Yep, that is where all the magic happens.
Be sure to use a 1% tolerance, to get the best results.
And please use SMD ones

[nemercry]

As we are currently doing a clearance sale(care this is advertising), we will make our version of the mod public domain.

Is your mod any different from the one in the first post?

Here is the mod I believe to be the simplest of them all thus far.
I found this after a bit of investigation and I have also just confirmed that it's the mod that nemercry has been talking about, testing and providing pics of for days.
I have not tried this mod yet but I intend to do so asap.

*********************************************************

*********************************************************
A regular 1/8W to 1/4W 1% to 5% axial resistor will work too. Try to shoot for 1% tolerance though.
And as usual, try it at your own risk and expense.
If you'd like me to make the mod for you, let me know via PM. I am located in the EUS.

And there you go wolfey.
Yep that is actually the mod how we are doing it.

Awesome!  Why is this way better than the others, and how fast have you gotten with this mod?

47kOhm 1% gives you stable 1100mhz to 1150mhz range 21,5 W Powerdraw including PSU
52kOhm 1% gives you stable 1200mhz 31W including PSU
56kOhm 1% gives you stable 1250mhz 44W including PSU

86kOhm 1% draw way to much and did turn off the device instantly (onboard powersupply is not rated for > 60W) we assumed it to take around 80W.
If you are funny you can try to use an 64kOhms resistor and you will probably get the highest possible frequency of 1300mhz.

[ZiG]

As we are currently doing a clearance sale(care this is advertising), we will make our version of the mod public domain.

Is your mod any different from the one in the first post?

Here is the mod I believe to be the simplest of them all thus far.
I found this after a bit of investigation and I have also just confirmed that it's the mod that nemercry has been talking about, testing and providing pics of for days.
I have not tried this mod yet but I intend to do so asap.

*********************************************************

*********************************************************
A regular 1/8W to 1/4W 1% to 5% axial resistor will work too. Try to shoot for 1% tolerance though.
And as usual, try it at your own risk and expense.
If you'd like me to make the mod for you, let me know via PM. I am located in the EUS.

And there you go wolfey.
Yep that is actually the mod how we are doing it.

Awesome!  Why is this way better than the others, and how fast have you gotten with this mod?

47kOhm 1% gives you stable 1100mhz to 1150mhz range 21,5 W Powerdraw including PSU
52kOhm 1% gives you stable 1200mhz 31W including PSU
56kOhm 1% gives you stable 1250mhz 44W including PSU

86kOhm 1% draw way to much and did turn off the device instantly (onboard powersupply is not rated for > 60W) we assumed it to take around 80W.
If you are funny you can try to use an 64kOhms resistor and you will probably get the highest possible frequency of 1300mhz.

SUPER...!...Excellent job, guys...Appreciate all your time and effort to experiment and share your findings...

What is the chip's voltage supply DVDD at these values of "R52"...?
And where...which point on the board do you measure that voltage...?

[simon66]

47kOhm 1% gives you stable 1100mhz to 1150mhz range 21,5 W Powerdraw including PSU
52kOhm 1% gives you stable 1200mhz 31W including PSU
56kOhm 1% gives you stable 1250mhz 44W including PSU

86kOhm 1% draw way to much and did turn off the device instantly (onboard powersupply is not rated for > 60W) we assumed it to take around 80W.
If you are funny you can try to use an 64kOhms resistor and you will probably get the highest possible frequency of 1300mhz.

At 56kOhm that would give a hash rate of around ~530Kh/s.

Also, 2 weeks ago while modding one of my gridseeds, I got real lazy and removed a SMD component from the device (By mistake). The damn resistor is soo small. Either way, I got it back together but it seems to have a solder bridge underneath it. Its been running fine since (I'm scared if I touch it more, I'll lose the SMD component)
Does any one knows the value of that resistor? Also, can I leave the solder bridge?
Here is a pic:



Thanks!

[nemercry]

47kOhm 1% gives you stable 1100mhz to 1150mhz range 21,5 W Powerdraw including PSU
52kOhm 1% gives you stable 1200mhz 31W including PSU
56kOhm 1% gives you stable 1250mhz 44W including PSU

86kOhm 1% draw way to much and did turn off the device instantly (onboard powersupply is not rated for > 60W) we assumed it to take around 80W.
If you are funny you can try to use an 64kOhms resistor and you will probably get the highest possible frequency of 1300mhz.

At 56kOhm that would give a hash rate of around ~530Kh/s.

Also, 2 weeks ago while modding one of my gridseeds, I got real lazy and removed a SMD component from the device (By mistake). The damn resistor is soo small. Either way, I got it back together but it seems to have a solder bridge underneath it. Its been running fine since (I'm scared if I touch it more, I'll lose the SMD component)
Does any one knows the value of that resistor? Also, can I leave the solder bridge?
Here is a pic:



Thanks!

i measured 1kOhm for it. Can someony verify this please?