Topic: GridSeed 5-chip USB miner voltage mod - page 16. (Read 156980 times)

Sure, just click one of the links under my account name....
good luck!

Thanks very much Wolfey! I'm at about .09 cents a kw here, which is about .08 cents USD.

Can you PM me your email? I might have a few questions when this is performed.

EDIT: Jesse's guide is definitive on the 49.9k mod, correct?

I'm going for top hash rate. I don't have to worry about power bills here.
I think 49.9k is the best option overall though. And it's up to 1250/1275 actually. Some actually hash pretty profitably at that speed.
Good luck!

Thanks Wolfey,

I'm still a bit confused though:

what's the better mod between these two below? The guy I have doing it is only familiar with 47k mod.

VMOD 3: (47k): Up to freq=1175 (500kH/s poolside average)  30 +/-4 watt
VMOD 3: (49.9k): Up to freq=1200 (510kH/s poolside average)   33 +/-4 watt

Just leave the top off. Add small indivdual heatsinks to the top of the chips. It allows a better airflow leabing it open. The air flow fro  the fan os pretty totally redticted due to the pcb. Leaving the top off also allows you to add a heat sink to the voltage regs. There is only. The top of the chips toucjing the heatsink. Really for mini g scrypt is it needed a smaller one or ones would be better. Remember these where desgined wattage and heat wise for the sha or dual mining mode.

thermal paste i used was left over non-conductive MX-4. it will be fun to clean this mess!!! I will think about the milling out that small part as you did.

Quoted for awesomeness, I applaud your efforts.

I would give it a go :-) ... send me the link

I will start a new thread when ready but in the meantime I would like to share with you the work in progress behind this new project based on sandor cpuminer.

I'd like to test it with a great bunch of pods (20 or more) but I have only 3 now, may be someone of you could test it? It requires a linux controller like a raspberry with a web server (something like a Scripta img should work very fine, just change the document root to the Minera directory).

If there is someone who wanna try it please leave me a PM, I think I will release a public beta-version next week.

Hope you like it:

Hardware errors are gonna vary from device to device chip to chip, even wiht same mod applied. for starters theres an error in resistor values even at 1%, for the resistor (r52 mod) then there is plenty of other resistors on the board as well - the main one thats gonna effect voltage is r50, connected to DGND from the buck convertor, plus the resistors for the DPLL voltage. All these will give a variance although small, but when measuring voltage in.00 volts it can make a difference.
Secondly these chips are Intel or AMD chips, manufactured to the same constiant and quality control as thoose so each chip itself will have a different optium performance. Not to mention the whole assembly of the grids isnt to the high standards and quality control we would like.

CPUminer i believe uses the hardware errors to adjust the hash rate, no hardware errors over x period hash rate goes up. x hardware errors over x period hasrate goes down. until it finds a balancing point.
When running a batch of grids from the same command file - with setting each one indivdually - a varying amount of hardware errors will be produced, as each device will start of the same and autclocked until it gets the hardware errors. After running CPUminer for say 24hr, if you take a note of the hash rate for each grid, set a batch file wiht autotune off and set each one indivdually youll probably find over the next 24 hours that the hardware errors are a lot lower if none at all.

Woww...

Isnt that too much HW errors? I am not happy if I get above 5 HW errors per 24 Hrs and I am getting 510KH

Heres perfomance indication of voltmod1 gridseeds and latest sandor cpuminer with autotune on.
Running for 11 hours.

Sandor has done great work! If you are running autotune on, then dont worry about HW errors. autotune takes out every last bit of perfomance of your gridseeds.  
PS. Red box around the faulty miner with only 1 chip working (mentioned earlier posts here).

Are u guys getting a lot of he he errors? I get about 12 a day at 460kh

did you have anny luck using this @Andareed? is it as simple as it seems, sorry for the noobis question and it may be in the thread somewere so forgive me if im asking double...BUT is it liquid soldering paste? you just mix and push it out the needle done deal ? thanks in advance great job! ENJOY MINING!

Could be blowing out due to becoming overwhelmed by too high a mean and/or peak current.
It could be (but shouldn't be) caused by the 49.9k mod due to the previous design's FB's having been substituted out for lower value to again, cut production costs or they are perhaps simply faulty chips in the first place. I hope the latter is the case or the 49.9k mod may now require upgrading certain power buss / support components like the FB's, to compensate for the increased power requirements of over-volting/clocking. See if the replacements ones get hot under normal conditions. If they do, perhaps it's due to the above or perhaps there is another yet discovered component issue. Could also simply be a run of bad pods. It happens.

Guys,

I have just found something out here.... And I am starting to realize why  sometimes the Grids are not working at the full potential on the pool side when you have quite a few seeds..

And Also for people who find CGminer crashing, this is the reason below.

The issue is the USB power, those cheapo Chinese Hubs are really bad and unstable and are hit and miss in terms off good or bad..... FOr example I bought 5 x 10 Port USB hubs only 2 work OK not GREAT but OK and the 3rd is MEhhhhh still trying to work out if it can handle all 10 ports filled up or not..

In-fact even the 2 that work properly sometimes all ports are not detected properly when the mining action starts sometimes I hear the USB disconnect windows sound On-OFF- On - OFF

Where's the ROFL emoticon!??? 

No problem.  Those parts should be pretty cheap, hopefully that's all that was damaged.  Only way to find out is to replace them with identical spec replacements.  Someone mentioned the possibility of temporarily bypassing those parts to verify functionality of the gridseed - however if it were mine, I'd replace the parts before testing it.

:EDIT:  What thermal paste did you use?  Non-conductive I hope.  You might want to clean that up while you've got it apart.  In my opinion, there's no real point in using thermal paste unless you are positive the heatsink makes full contact with all 5 gc3355 chips.  On all the gridseeds I have there are 2 components which are taller than the gc3355's and prevent full contact.  I milled out part of the heatsink over those two components so the heatsink made full contact.   I posted a pic in this thread somewhere of it.  However, if you do that, then the heatsink will likely make contact with all the capacitors surrounding the gc3355's.  So I covered those with electrical tape to prevent a short.

Thanks for the help!

The footprint is actually listed as R1206.  I believe those are part of the 12v circuitry on the board, so it could be from a surge of some sort I suppose.  I've seen another report of those beads blowing for someone else but I don't recall what the total damage (beads + collateral) was.

EDIT:  For reference, the information about the board layout and parts list is on github here: https://github.com/gridseed/gc3355-doc or here: https://github.com/gridseed/usb-miner