GRIDSEED G-BLADE Overclocking 7Mh/s, improvements and repair

[J4bberwock]

As said earlier, I bought 1 blade to try to voltmod it.
Mine works stock around 6Mh/s @ 875Mhz with less than 0.1% HW errors.

Disassembly is really easy, 10 screws to remove: 6 for joining the 2 PCB, and 4 for the fan.

First thing that you will notice when seeing the PCB is that it will need better cooling if overclocked.

The chips are simply cooled by the fan blowing air on them.
No heatshink or so.

The voltmod will be the same principle as the one on the 5 chips pod:

Replacing the good resistor (that is still a 33k) with a bigger one, up to 50k maybe.

To be safe, I'll go step by step, increasing the value slowly.



Pictures and updates soon.

Edit:

Here is what I used to make all my mods

https://bitcointalk.org/index.php?topic=576784.msg7298275#msg7298275

And here is a step by step testing for a failed G-Blade that will help me/you fix it.

https://bitcointalk.org/index.php?topic=576784.msg7330855#msg7330855

The only part not covered is when the STM32 chip controlling USB is fried.
I'll update it later when we'll be sure that the firmware I've extracted works correctly.

[J4bberwock]

first proof of work



Not as easy as you should imagine, the power stage on the PCB is almost at its limits.

resistor replaced with 39k. Everything over this point will work for a few minutes before stopping sending shares or even worst, blowing the 16V 220uF filtering capacitor.
25V should be the good value anyway when powering with 12V.

239 watt at wall.

More pics and info will follow

[GenTarkin]

Pretty awesome!
Which supplier did you buy yours from? Im trying to figure out if GAWminers(atari02) is reputable or not...

[J4bberwock]

Pretty awesome!
Which supplier did you buy yours from? Im trying to figure out if GAWminers(atari02) is reputable or not...

Don't know about Gawminers, but for Europe, MinerEU is cheap (considering I should pay VAT and impor duties) and fast to ship.
Zoomhash looks ok too, got a few pods from them earlier.

[MatthewBCF]

Pretty awesome!
Which supplier did you buy yours from? Im trying to figure out if GAWminers(atari02) is reputable or not...

Gawminers is reputable.  I've had 3 solid orders including blade (which arrives this wed).  Of course how can you trust me?  I guess I could put up a shipping label of completed tracking number, but I also suggest calling oneself - There is a real full staff and they actually answer their phones.  The owner can be looked up online easily enough if you call them.  They def have some growing pains but also have a policy to compensate for every day that a delivery goes past 5 days.  The prices/deals/rewards beat anyone that I could find.  I've been meaning to write a larger review once I get my blades..

[J4bberwock]

Don't try this at home unless you know what you are doing.
Serious damages can happen and is not limited to you, your family, your G-Blade, your house.
I can't be held responsible for any damage that can happen if you try this voltmod. It's still in early stage of testing to improve stability and reduce overheating.

Here are more pics from the mod with 50K pot to go slowly on overvolting.
The 2 disassembled PCB


Here is a close up view of the place where the 33k resistor needs to be swapped.


And here is the wiring made plus a few comments on  blown components and overheating area.





One of the culprits for overheating might be the ferrite beads, I'll try to replace them with higher capacity ones that should be delivered soon.
Please note that the power connector will also be at its limits or a little over them when overvolting, so another component that needs to be replaced.

[nikolaz]

Pretty awesome!
Which supplier did you buy yours from? Im trying to figure out if GAWminers(atari02) is reputable or not...

I have ordered mine through Hashra -- $1,600 for Blade, PSU, Raspberry Pi and all of the cables.... Just hoping DHL will deliver them tomorrow :-) I have been in constant touch with these guys and also they do provide their own image for the blades.

Check Gridseed's website for official list of sellers.

[Gentso1]

I know this is a little off-topic but how many blades can you run on 1 ras pi?

[viriat0]

Good work man!

[nikolaz]

I know this is a little off-topic but how many blades can you run on 1 ras pi?

I have asked the same question, I have seen a video of someone running multiple blades however he was running it via a PC.

[razorskiss1000]

I believe to run more than one blade per raspberry pi you need a powered USB strip and then I think I saw that it could really only handle 5 blade units. aka 10 boards. The question I have though is could I buy small copper heatsinks and possible longer standoffs. Assemble all this and have more overclocking headroom? Or is the volt mod required to hit those higher clocks?

[J4bberwock]

I believe to run more than one blade per raspberry pi you need a powered USB strip and then I think I saw that it could really only handle 5 blade units. aka 10 boards. The question I have though is could I buy small copper heatsinks and possible longer standoffs. Assemble all this and have more overclocking headroom? Or is the volt mod required to hit those higher clocks?

You won't gain anything with better cooling, the fan blowing air over the chips seems to be enough, even when overclocked, they are warm at most.
Voltmod is required for real overclocking.

[soothaa]

So what I'm hearing is that these chips are nowhere near their maximum speed, and if the blade was engineered just slightly better they could be pushed way faster? Well dam. Makes me wanna try and mod the heck out of the power board..

[wolfey2014]

I believe to run more than one blade per raspberry pi you need a powered USB strip and then I think I saw that it could really only handle 5 blade units. aka 10 boards. The question I have though is could I buy small copper heatsinks and possible longer standoffs. Assemble all this and have more overclocking headroom? Or is the volt mod required to hit those higher clocks?

You won't gain anything with better cooling, the fan blowing air over the chips seems to be enough, even when overclocked, they are warm at most.
Voltmod is required for real overclocking.

Hello J4! Nice work!
Have you read the latest over volt report at http://cryptomining-blog.com/ rel volt modding the new gridseed g-blade scrypt asic miner?
They are saying that the voltage regulators overheat easily at even 39k ohms but can be compensated with additional heat sink and fan. Still, the overcurrents will possibly cause them to release magic black smoke!
My first thought is to replace them with TO-220 type with separate fin type heat sinks to help them catch the wind of the main cooling fan, which also sounds like it can be under-volted to make it run quieter since it provide well more than enough air flow to begin with.
Let me know what you think.
Wolfey

[J4bberwock]

I believe to run more than one blade per raspberry pi you need a powered USB strip and then I think I saw that it could really only handle 5 blade units. aka 10 boards. The question I have though is could I buy small copper heatsinks and possible longer standoffs. Assemble all this and have more overclocking headroom? Or is the volt mod required to hit those higher clocks?

You won't gain anything with better cooling, the fan blowing air over the chips seems to be enough, even when overclocked, they are warm at most.
Voltmod is required for real overclocking.

Hello J4! Nice work!
Have you read the latest over volt report at http://cryptomining-blog.com/ rel volt modding the new gridseed g-blade scrypt asic miner?
They are saying that the voltage regulators overheat easily at even 39k ohms but can be compensated with additional heat sink and fan. Still, the overcurrents will possibly cause them to release magic black smoke!
My first thought is to replace them with TO-220 type with separate fin type heat sinks to help them catch the wind of the main cooling fan, which also sounds like it can be under-volted to make it run quieter since it provide well more than enough air flow to begin with.
Let me know what you think.
Wolfey

Hey Wolfey,

The post wasn't there a few hours ago, but they are facing the exact same limitations as me, but they haven't noticed the ferrite beads overheating. Thermal picture wold be nice to identify where are the hot/weak spots.
I managed to get the blade stable for 25 minutes at 1125Mhz, giving 3800Kh/s for the panel with 47K resistor, but after that, it's overheating, even with a fan blowing directly on it and stops sending shares
It's actually running with very few hw errors at 1063Mhz with 42k resistor.

TO-220 package might be a good idea to replace the 09N03. Datasheet says 25V 50A, but power dissipation might be too low I'll have to check if I have an acceptable replacement when back home next week.

[wolfey2014]

I believe to run more than one blade per raspberry pi you need a powered USB strip and then I think I saw that it could really only handle 5 blade units. aka 10 boards. The question I have though is could I buy small copper heatsinks and possible longer standoffs. Assemble all this and have more overclocking headroom? Or is the volt mod required to hit those higher clocks?

You won't gain anything with better cooling, the fan blowing air over the chips seems to be enough, even when overclocked, they are warm at most.
Voltmod is required for real overclocking.

Hello J4! Nice work!
Have you read the latest over volt report at http://cryptomining-blog.com/ rel volt modding the new gridseed g-blade scrypt asic miner?
They are saying that the voltage regulators overheat easily at even 39k ohms but can be compensated with additional heat sink and fan. Still, the overcurrents will possibly cause them to release magic black smoke!
My first thought is to replace them with TO-220 type with separate fin type heat sinks to help them catch the wind of the main cooling fan, which also sounds like it can be under-volted to make it run quieter since it provide well more than enough air flow to begin with.
Let me know what you think.
Wolfey

Hey Wolfey,

The post wasn't there a few hours ago, but they are facing the exact same limitations as me, but they haven't noticed the ferrite beads overheating. Thermal picture wold be nice to identify where are the hot/weak spots.
I managed to get the blade stable for 25 minutes at 1125Mhz, giving 3800Kh/s for the panel with 47K resistor, but after that, it's overheating, even with a fan blowing directly on it and stops sending shares
It's actually running with very few hw errors at 1063Mhz with 42k resistor.

TO-220 package might be a good idea to replace the 09N03. Datasheet says 25V 50A, but power dissipation might be too low I'll have to check if I have an acceptable replacement when back home next week.

Which components exactly are the FET's or Voltage Regulators on the card. I don't have one so I can't find out for myself.
You can parallel FET's to achieve maximum 'overhead' current capacity. You can increase capacitor value/voltage by adding more caps, like they do on motherboards for cleaner power and good of not excellent quiescent current characteristics.
Darn things! They make them cheaply by cutting corners forcing us to spend more doe and engineering time to make them what they can/should be in the first place! Oh well, that's part of the profit vs modding game. They are helping us too in a way, I guess

Can you provide me with the data sheet on the blades? I'd love to see it and follow along.

You're making progress! Excellent!

[J4bberwock]

Can you guess which one has the 42k resistor and which one still have the 39k?



The schematics for the blade is the 8 chip one from github.
At least, it's really close if it's not the good one.

Unfortunately, it seeems they have kept the same power board for the 40 chips blade that was supposed to be used for 8 chips, so not much room for overclocking.

[wolfey2014]

Can you guess which one has the 42k resistor and which one still have the 39k?



The schematics for the blade is the 8 chip one from github.
At least, it's really close if it's not the good one.

Unfortunately, it seeems they have kept the same power board for the 40 chips blade that was supposed to be used for 8 chips, so not much room for overclocking.

Yo J4bberwock

I don't understand your question quite clearly enough re: 42k vs 39k ?

Alright, thanks. I have the 8 chip schematic on hand.

Right, I read that about the weak links on the driver portion of the cards. That's why I suggest larger value components which will translate to somewhat larger discreet components. But they can all be made to fit nicely on the card, I am sure. Then we can really sock it to it! Right?

Those figures of 3618 to 3622 are excellent! Do you think that is maximum speed? Or perhaps lowering the clock to something slightly less is already optimum?

Good work!

[bamsterdam]

I have a question the 7mh-s is after the voltmod right?

Its a little disappointing I got mine tomorrow so I will follow this tread closely   

Thanks

[J4bberwock]

42K resistor gives way less HW errors at 1063Mhz

7.3Mh/s seems to be the limit with the actual components on the powerboard.
Many components are getting really hot and need active cooling to work.

I'll try some improvements on the powerboard later, as suggested by wolfey.
For now, I'm happy with the results, but it's really a shame that Gridseed haven't designed a better powerboard to get the full potential from the chips.