Avalon ASIC users thread - page 97. | Bitcointalksearch.org

WinTame2012

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Quote from: kano on August 16, 2013, 03:31:36 PM

Quote from: WinTame2012 on August 16, 2013, 11:12:47 AM

Quote from: crazyearner on August 15, 2013, 09:44:49 PM

Quote from: WinTame2012 on August 15, 2013, 06:28:22 PM

Moved from bitparking to 50btc and now I'm constantly getting a lot of Rejected shares at Diff8 Huh

Does anybody have fixed issue like this?

Edit: FW both 20130703 and 20130723

Change your diff to 64 on 50btc under settings for miner is probs why you getting too many rejected shares.

Thanks. Did it already. Looks like it helps.

No, that's not actually making it better unless there is an actual problem with the pool - which would mean don't use the pool.
Going from 8diff to 64diff simply means your Reject share variance increases.
Coz on average you find 1/8 of the rejected shares ... but they are worth 8 times as much each.

I calculate it in the %age to accepted Diff64 shares. And it works. But 50btc is not ideal pool, I consider to move on.

-ck

legendary

Activity: 4088

Merit: 1631

Ruu \o/

Quote from: kano on August 16, 2013, 03:31:36 PM

Quote from: WinTame2012 on August 16, 2013, 11:12:47 AM

Quote from: crazyearner on August 15, 2013, 09:44:49 PM

Quote from: WinTame2012 on August 15, 2013, 06:28:22 PM

Moved from bitparking to 50btc and now I'm constantly getting a lot of Rejected shares at Diff8 Huh

Does anybody have fixed issue like this?

Edit: FW both 20130703 and 20130723

Change your diff to 64 on 50btc under settings for miner is probs why you getting too many rejected shares.

Thanks. Did it already. Looks like it helps.

No, that's not actually making it better unless there is an actual problem with the pool - which would mean don't use the pool.
Going from 8diff to 64diff simply means your Reject share variance increases.
Coz on average you find 1/8 of the rejected shares ... but they are worth 8 times as much each.

That's right. It's not a solution.

If 50BTC is using a large coinbase, you might have been getting struck by the excessive CPU usage limitation in older firmware just like p2pool was. This might manifest as duplicate shares and only show up as rejects at your pool. Most of the recent updates were created to address precisely that problem. Try my latest firmware.

http://ck.kolivas.org/apps/cgminer/avalon/20130814/

kano

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Linux since 1997 RedHat 4

Quote from: WinTame2012 on August 16, 2013, 11:12:47 AM

Quote from: crazyearner on August 15, 2013, 09:44:49 PM

Quote from: WinTame2012 on August 15, 2013, 06:28:22 PM

Moved from bitparking to 50btc and now I'm constantly getting a lot of Rejected shares at Diff8 Huh

Does anybody have fixed issue like this?

Edit: FW both 20130703 and 20130723

Change your diff to 64 on 50btc under settings for miner is probs why you getting too many rejected shares.

Thanks. Did it already. Looks like it helps.

No, that's not actually making it better unless there is an actual problem with the pool - which would mean don't use the pool.
Going from 8diff to 64diff simply means your Reject share variance increases.
Coz on average you find 1/8 of the rejected shares ... but they are worth 8 times as much each.

lastbit

full member

Activity: 206

Merit: 100

Quote from: GandalfG on August 16, 2013, 11:12:04 AM

It is Avalon clone based on B2 design that I build self.

Congrats!

S M I L Y

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Activity: 113

Merit: 10

https://www.chynge.net/

Quote

How about B3 machines that have changed design ? I see on one photos hash unit are probably grouped in 4 on one PCB and added thermal sensor on it.

My unit is a batch 3. It looks like we are seeing the exact same voltage drop.

WinTame2012

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Activity: 315

Merit: 250

Official sponsor of Microsoft Corp.

Quote from: crazyearner on August 15, 2013, 09:44:49 PM

Quote from: WinTame2012 on August 15, 2013, 06:28:22 PM

Moved from bitparking to 50btc and now I'm constantly getting a lot of Rejected shares at Diff8 Huh

Does anybody have fixed issue like this?

Edit: FW both 20130703 and 20130723

Change your diff to 64 on 50btc under settings for miner is probs why you getting too many rejected shares.

Thanks. Did it already. Looks like it helps.

GandalfG

sr. member

Activity: 259

Merit: 250

Dig your freedom

Quote from: GenTarkin on August 16, 2013, 09:49:02 AM

Quote from: GandalfG on August 16, 2013, 05:00:44 AM

Quote from: S M I L Y on August 15, 2013, 09:58:23 PM

Thanks lastbit and GandalfG for the info. I have access to a nice 12ghz oscilloscope and will take noise and ripple measurements of the output of the VR and see if it gets unstable past 20a.

Just took some measurements. At the top of the board closest to the VR im seeing 1.2v at the bottom im seeing 1.15v! Im surprised to see so much of a drop! They must have cheeped out on the amount of copper on the board.

I measure my board with my 100MHz oscilloscope with 1.3V mod and did not see noise on power lines. I check it now after over 10 days mining.
About drop:
Standby: 1.298V
395MHz:
1.278 on coil VR and nearest capacitor
1.268 first two chip
1.228 last chip.

I solder silver-plated wire 0,8mm across one board and check how its help.

Have any amps / watts per board power measurement?
Also, was this a b2 or b3? Did they change anything on the b3 miner boards?

I did not measure amps. It is Avalon clone based on B2 design that I build self. Buy PCB and parts from Strombom.
Actually have only 50 chip and patiently wait for supply from Bitsyncom.

Quote from: S M I L Y on August 16, 2013, 10:57:53 AM

Quote from: lastbit on August 16, 2013, 06:00:46 AM

50mv drop is horrible!

adding a couple thick wires from the output of the VR to the last chips should help a lot. although the problem could be a return path issue. I dont have my unit in front of me at the moment. I assume the bottom layer is Ground and the top is VCC? There may be an issue with the ground vias/pins not being able to handle the current.

Yes that huge drops are very undesirable. As I stated I solder wire and make measure again. I'm a little surprised that the original B1/B2 have a similar problem.
How about B3 machines that have changed design ? I see on one photos hash unit are probably grouped in 4 on one PCB and added thermal sensor on it.

S M I L Y

member

Activity: 113

Merit: 10

https://www.chynge.net/

Quote from: lastbit on August 16, 2013, 06:00:46 AM

Quote from: GandalfG on August 16, 2013, 05:00:44 AM

I measure my board with my 100MHz oscilloscope with 1.3V mod and did not see noise on power lines. I check it now after over 10 days mining.
About drop:
Standby: 1.298V
395MHz:
1.278 on coil VR and nearest capacitor
1.268 first two chip
1.228 last chip.

I solder silver-plated wire 0,8mm across one board and check how its help.

Thanks for the info. It looks like it's more work to do. Loosing 3% hashrate for voltage drops would be sad.

50mv drop is horrible!

adding a couple thick wires from the output of the VR to the last chips should help a lot. although the problem could be a return path issue. I dont have my unit in front of me at the moment. I assume the bottom layer is Ground and the top is VCC? There may be an issue with the ground vias/pins not being able to handle the current.

GenTarkin

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Activity: 2450

Merit: 1002

Quote from: GandalfG on August 16, 2013, 05:00:44 AM

Quote from: S M I L Y on August 15, 2013, 09:58:23 PM

Thanks lastbit and GandalfG for the info. I have access to a nice 12ghz oscilloscope and will take noise and ripple measurements of the output of the VR and see if it gets unstable past 20a.

Just took some measurements. At the top of the board closest to the VR im seeing 1.2v at the bottom im seeing 1.15v! Im surprised to see so much of a drop! They must have cheeped out on the amount of copper on the board.

I measure my board with my 100MHz oscilloscope with 1.3V mod and did not see noise on power lines. I check it now after over 10 days mining.
About drop:
Standby: 1.298V
395MHz:
1.278 on coil VR and nearest capacitor
1.268 first two chip
1.228 last chip.

I solder silver-plated wire 0,8mm across one board and check how its help.

Have any amps / watts per board power measurement?
Also, was this a b2 or b3? Did they change anything on the b3 miner boards?

ProfMac

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Activity: 1246

Merit: 1002

Quote from: lastbit on August 16, 2013, 07:21:10 AM

Quote from: crazyearner on August 15, 2013, 09:44:49 PM

lastbit in terms of what your doing you might want to try this as modding not uploaded all details yet but this s on a batch 2 unit and working out the layout for batch 3 will have details on my website when I get around to it.

Thanks crazyearner. Indeed something along the lines of what you did. But batch#3 id different, each 2 modules are arranged in mirror with heatsinks facing one another. And I'd like to keep high airflow on the pcb and chips surfaces too because I believe it may play an important part in cooling.

The pattern of holes attaching the heatsink to the bottom plate is different between batch #2 and batch #2. Batch #2 uses 7 holes, Batch #3 uses 5 holes.

Has anyone made a hole matching plate, perhaps 3 mm aluminum with countersunk holes?

lastbit

full member

Activity: 206

Merit: 100

Quote from: crazyearner on August 15, 2013, 09:44:49 PM

lastbit in terms of what your doing you might want to try this as modding not uploaded all details yet but this s on a batch 2 unit and working out the layout for batch 3 will have details on my website when I get around to it.

Thanks crazyearner. Indeed something along the lines of what you did. But batch#3 id different, each 2 modules are arranged in mirror with heatsinks facing one another. And I'd like to keep high airflow on the pcb and chips surfaces too because I believe it may play an important part in cooling.

GandalfG

sr. member

Activity: 259

Merit: 250

Dig your freedom

If migrate, only to Burnin board.

1 -20 chip instead 16.
2 - Very stable work at 400MHz
3 - programmable VR

Ytterbium

full member

Activity: 238

Merit: 100

Well, you could always buy blank Klondike boards, then remove the chips and re-solder them Tongue

. A 3-module Avalon would take 15 K16s. If you could run them at 400, you'd get a ~14% improvement over 350.

lastbit

full member

Activity: 206

Merit: 100

Quote from: GandalfG on August 16, 2013, 05:00:44 AM

I measure my board with my 100MHz oscilloscope with 1.3V mod and did not see noise on power lines. I check it now after over 10 days mining.
About drop:
Standby: 1.298V
395MHz:
1.278 on coil VR and nearest capacitor
1.268 first two chip
1.228 last chip.

I solder silver-plated wire 0,8mm across one board and check how its help.

Thanks for the info. It looks like it's more work to do. Loosing 3% hashrate for voltage drops would be sad.

GandalfG

sr. member

Activity: 259

Merit: 250

Dig your freedom

Quote from: Ytterbium on August 16, 2013, 04:48:25 AM

If all you have to do is lower some resistance to get it to 1.2v, or 1.3v - couldn't you actually just solder another resistor in parallel to lower the resistance the correct amount? You wouldn't need to remove anything that way.

One problem, of course is that the boards would run hotter even at the same clock speeds...

Its no problem set 1.3V or higher. VR can supply more amps.
The real problem now are cheap PCB Sad

Too thin copper layer generate huge voltage drop on end of board.

GandalfG

sr. member

Activity: 259

Merit: 250

Dig your freedom

Quote from: S M I L Y on August 15, 2013, 09:58:23 PM

Thanks lastbit and GandalfG for the info. I have access to a nice 12ghz oscilloscope and will take noise and ripple measurements of the output of the VR and see if it gets unstable past 20a.

Just took some measurements. At the top of the board closest to the VR im seeing 1.2v at the bottom im seeing 1.15v! Im surprised to see so much of a drop! They must have cheeped out on the amount of copper on the board.

I measure my board with my 100MHz oscilloscope with 1.3V mod and did not see noise on power lines. I check it now after over 10 days mining.
About drop:
Standby: 1.298V
395MHz:
1.278 on coil VR and nearest capacitor
1.268 first two chip
1.228 last chip.

I solder silver-plated wire 0,8mm across one board and check how its help.

Ytterbium

full member

Activity: 238

Merit: 100

If all you have to do is lower some resistance to get it to 1.2v, or 1.3v - couldn't you actually just solder another resistor in parallel to lower the resistance the correct amount? You wouldn't need to remove anything that way.

One problem, of course is that the boards would run hotter even at the same clock speeds...

GenTarkin

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Activity: 2450

Merit: 1002

Quote from: S M I L Y on August 15, 2013, 09:58:23 PM

I have access to a nice 12ghz oscilloscope and will take noise and ripple measurements of the output of the VR and see if it gets unstable past 20a.

That would be awesome =)

S M I L Y

member

Activity: 113

Merit: 10

https://www.chynge.net/

Thanks lastbit and GandalfG for the info. I have access to a nice 12ghz oscilloscope and will take noise and ripple measurements of the output of the VR and see if it gets unstable past 20a.

I am running a 1200w supply so I should be fine on the supply side. Going to be switching to 220v as well to gain a bit more efficiency.

I will be running coolant to a radiator outside for watercooling... Unfortunately it has been 105f or 40c for the last month outside. Which is even more reason I want to get the 800+watt this thing produces out of my house!

The main issue I see with cooling is getting the heat from the chips into the heatsink. lastbit's photo earlier show the exact bowing away Im seeing.
As the board heats up you can watch it bow away. I have a clamping solution im working on as well to hold the chips flat against the heatsink.

Just took some measurements. At the top of the board closest to the VR im seeing 1.2v at the bottom im seeing 1.15v! Im surprised to see so much of a drop! They must have cheeped out on the amount of copper on the board.

crazyearner

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Activity: 1820

Merit: 1001

lastbit in terms of what your doing you might want to try this as modding not uploaded all details yet but this s on a batch 2 unit and working out the layout for batch 3 will have details on my website when I get around to it.

Avalon before pictures

Avalon after air flow mods.

Temps before and after more or less the same but not using as much fan power and after mining 24 hours sold this is running nice and cool with oc to 84GH also fans never go above 1800 now so lot better results still doing other mods in time to it to get better air flow. This is with no extra fans added maybe get even better results with some delta fans in but their too noise

Have also taken unit upto 90GH however too many hw% errors however temps solid 50c so not doing too bad. Also added new 860w corsair digital psu working perfect never takes over 730w

Quote from: WinTame2012 on August 15, 2013, 06:28:22 PM

Moved from bitparking to 50btc and now I'm constantly getting a lot of Rejected shares at Diff8 Huh

Does anybody have fixed issue like this?

Edit: FW both 20130703 and 20130723

Change your diff to 64 on 50btc under settings for miner is probs why you getting too many rejected shares.

Topic: Avalon ASIC users thread - page 97. (Read 438596 times)