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Topic: Avalon ASIC users thread - page 135. (Read 438724 times)

legendary
Activity: 1764
Merit: 1002
July 05, 2013, 12:00:02 PM
con,

is a vardiff of 236 getting too high?
legendary
Activity: 1820
Merit: 1001
July 05, 2013, 11:49:23 AM
I have a retail TP-Link 703n flashed with the Avalon software.  It is running on my network so I can learn the interface before delivery.

Today I notice a large number of attempts to log in as root from 59.53.94.9
This may be an address in China, no DNS names are returned after the chinatelecom.10gigabitethernet6-1.core1.lax1.he.net hop.



Where did you find the logs for login attempts ?
sr. member
Activity: 277
Merit: 254
July 05, 2013, 11:24:31 AM
Maybe a noobish question, but can't find answer to that:

How do I display UI of cgminer in my ssh session when cgminer runs as default (automatic service)?
I like the UI, want to play with pools, change them easily ...

And if it is not possible to bring that cgminer to my ssh session terminal, how do you switch pools? -> using cgminer-api
legendary
Activity: 1246
Merit: 1002
July 05, 2013, 10:07:04 AM
I have a retail TP-Link 703n flashed with the Avalon software.  It is running on my network so I can learn the interface before delivery.

Today I notice a large number of attempts to log in as root from 59.53.94.9
This may be an address in China, no DNS names are returned after the chinatelecom.10gigabitethernet6-1.core1.lax1.he.net hop.

sr. member
Activity: 302
Merit: 252
July 05, 2013, 09:34:11 AM
I noticed that the numbers of Fan# and Temp# are interchanged. Temp3 is alwas a bit more than Temp2, though Fan2 runs faster than Fan3.

Is that only how it is shown or maybe the fans are connected to the wrong output ? How to find out ?

legendary
Activity: 1820
Merit: 1001
July 05, 2013, 09:27:35 AM
Any ways on reducing hw errors and also  how to update to latest cgminer or use cgminer separate to one in config of Avalon ?
legendary
Activity: 1600
Merit: 1014
July 05, 2013, 08:55:49 AM
I found the R9, unnecessary to mention that it is fucking small  Wink

I guess it doesn't pay of to tweak around with the voltage, don't think that anybody will on existing boards.
legendary
Activity: 1610
Merit: 1000
July 05, 2013, 07:28:43 AM
Quote
What would it take for a volt mod? Soldering around on every single step down converter?

Yes, you need to change R9 resistor value in step-down converter, according to datasheet on TPS40193
the formula is

R9 = ( Vfb * R10 ) / ( Vout - Vfb ) , where Vfb is constant = 0.591v , R10 = 10.5k

for example, calculation for Vout = 1.2 give

R9 = ( 0.591 * 10500 ) / ( 1.2 - 0.591 ) = 6205.5 / 0.609 = 10189 , 10k resistor

in datasheet maximum Vout = 1.32

R9 = ( 0.591 * 10500 ) / ( 1.32 - 0.591 ) = 6205.5 / 0.729 = 8512 , 8.5k resistor

To make ~ 8.5k resistor from 10k you need to add in parellel 60k resistor, but i would advice you try to increase voltage in a little steps like 0.01v before you reach 1.32v

Sorry but i cant point you now where is that resistor located, i just look at hash_unit schematics.

Quote
How far (in % of HW errors) can I go up with the frequency without risking of damaging something?
I think hw error rate 2-3% is the highest that you want to see, more than that is a waste of energy.
You can damage the chips by increasing voltage to more than 1.32v - be careful.
invader ,

Nice reading thank you  Wink

What about TPS40193? it was rated at 20A max. Will it burn into flames? At 350 each chip according to rumors (calcs on PSU input - Wall) eats about 1.8-1.9 A

What about other elements inductors and such?

Thank you in advance
legendary
Activity: 1600
Merit: 1014
July 05, 2013, 07:28:24 AM
At least in datasheet i see operating temperature range [ -20 .. +85 ]
Are you sure that's not Tj?
sr. member
Activity: 266
Merit: 250
July 05, 2013, 07:15:30 AM
Quote
What would it take for a volt mod? Soldering around on every single step down converter?

Yes, you need to change R9 resistor value in step-down converter, according to datasheet on TPS40193
the formula is

R9 = ( Vfb * R10 ) / ( Vout - Vfb ) , where Vfb is constant = 0.591v , R10 = 10.5k

for example, calculation for Vout = 1.2 give

R9 = ( 0.591 * 10500 ) / ( 1.2 - 0.591 ) = 6205.5 / 0.609 = 10189 , 10k resistor

in datasheet maximum Vout = 1.32

R9 = ( 0.591 * 10500 ) / ( 1.32 - 0.591 ) = 6205.5 / 0.729 = 8512 , 8.5k resistor

To make ~ 8.5k resistor from 10k you need to add in parellel 60k resistor, but i would advice you try to increase voltage in a little steps like 0.01v before you reach 1.32v and look at hw error rate.

Sorry but i cant point you now where is that resistor located, i just look at hash_unit schematics.

Quote
How far (in % of HW errors) can I go up with the frequency without risking of damaging something?

I think hw error rate 2-3% is the highest that you want to see, more than that is a waste of energy.
You can damage the chips by increasing voltage to more than 1.32v - be careful.
legendary
Activity: 1064
Merit: 1000
July 05, 2013, 07:05:01 AM
fans are almost at max..... but tempratures look low wnough

what's the max, 4000?

One machine here both coolers runs close to 4000, 39xx 
and the other one has one fan that max out at 3720
legendary
Activity: 1600
Merit: 1014
July 05, 2013, 05:26:46 AM
Quote
I was thinking about reworking the original heatsinks to fit on the top...
It's useless in general, too much work for too little effort. Better pay more attention to thermal contact of PCB bottom and heatsink. Also thanks for pictures, i noticed your chips is at 50 c, thats a good temperature - they will work fine up to 100c as was said somewhere. At least in datasheet i see operating temperature range [ -20 .. +85 ]

The plate would only be for better thermal contact of PCB bottom and heatsink. The PCB is just too soft to be pressed against the aluminium properly over the whole surface just by the few screws.

What would it take for a volt mod? Soldering around on every single step down converter?

How far (in % of HW errors) can I go up with the frequency without risking of damaging something? What's the time frame the --avalon-auto option uses to calculate the HW error rate and adjust the frequency?
 
hero member
Activity: 826
Merit: 1001
July 05, 2013, 05:13:44 AM
Mine has been upside down most of the time without a problem. It all looked pretty well secured when I opened it up and heat radiates from the "base" when it's upside down.
If it's a silver unit I wouldn't put it upside down. Just have a look at the few number of threads of the screws that hold the heavy boards to the case: https://bitcointalksearch.org/topic/avalon-batch-2-damage-repaired-it-211928

If it's a black unit, I have seen messages that this issue has been solved.
-ck
legendary
Activity: 4088
Merit: 1631
Ruu \o/
July 05, 2013, 03:12:06 AM
--avalon-auto seams working now, maybe I just was too impatient. I just don't get the results I wanted with my water cooling, frequency is on 354 now with the auto option. I am thinking of applying thermal paste to the back and an aluminum plate to the front which really presses the chips down onto the heatsink.
Heat's not the rate limiting thing for frequency it seems. In cold weather mine isn't getting hot but I can't get it up much past 355. The chips probably need a voltage mod to run at higher frequencies than that, but at least you've sorted out the heat side.
sr. member
Activity: 266
Merit: 250
July 05, 2013, 03:09:48 AM
Quote
I was thinking about reworking the original heatsinks to fit on the top...
It's useless in general, too much work for too little effort. Better pay more attention to thermal contact of PCB bottom and heatsink. Also thanks for pictures, i noticed your chips is at 50 c, thats a good temperature - they will work fine up to 100c as was said somewhere. At least in datasheet i see operating temperature range [ -20 .. +85 ]
legendary
Activity: 1600
Merit: 1014
July 05, 2013, 03:04:22 AM
... and an aluminum plate to the front which really presses the chips down onto the heatsink.
It has been said many times not to put anything on top of the chips. You'll destroy them.

It was said because putting anything on chips would make air pass worse thru the aircooled unit and will decrease overall cooling efficiency. Also was noted that chips has bad thermal conductivity on top due to the air gap in chip package, so most of the heat is going to the bottom where is good thermal conductivity exist and then to pcb.

I was thinking about reworking the original heatsinks to fit on the top...
sr. member
Activity: 266
Merit: 250
July 05, 2013, 02:58:42 AM
... and an aluminum plate to the front which really presses the chips down onto the heatsink.
It has been said many times not to put anything on top of the chips. You'll destroy them.

It was said because putting anything on chips would make air pass worse thru the aircooled unit and will decrease overall cooling efficiency. Also was noted that chips has bad thermal conductivity on top due to the air gap in chip package, so most of the heat is going to the bottom where is good thermal conductivity exist and then to pcb. But really, i think screws on PCB is just enough for purpose of "pressing to heatsink"
-ck
legendary
Activity: 4088
Merit: 1631
Ruu \o/
July 05, 2013, 02:34:08 AM
Mine has been upside down most of the time without a problem. It all looked pretty well secured when I opened it up and heat radiates from the "base" when it's upside down.
legendary
Activity: 1112
Merit: 1000
July 05, 2013, 02:16:24 AM
Anybody mentioned the fact that the unit gets real hot at the bottom?
Any advise to make that better or doesn't that really matter? Maybe place it upside down ?

They get hot on the bottom because the hashing module is screwed to the heatsink and the heatsink is screwed to the bottom of the case. As the heatsink is not touching the top of the case, the top does not get hot.

The internal fans should do the job of keeping things cool, the bottom will not get hotter than the heatsink anyways

You can add additional air cooling externally on the case bottom if that makes you feel more comfortable.

Keep the case horizontally. I would not flip it upside down, that would make the hashing modules hang from the top, it was not designed for that.
sr. member
Activity: 302
Merit: 252
July 05, 2013, 02:05:59 AM
Anybody mentioned the fact that the unit gets real hot at the bottom?
Any advise to make that better or doesn't that really matter? Maybe place it upside down ?
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