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Topic: BFL Single air flow? - page 3. (Read 6919 times)

legendary
Activity: 2955
Merit: 1049
September 09, 2013, 03:13:39 PM
#27
is it possible that my BFL LS has this problems because airflow?
Code:
2013.09.09 [17:11]  BitFORCE (ttyUSB0) ERROR: Unexpected response without command: BitForce SHA256 SC 1.0 
2013.09.09 [17:11]  BitFORCE (ttyUSB0) ERROR: Command timed out. Retries: 0
2013.09.09 [17:11]  Probe of port /dev/ttyUSB0 failed: timeout
2013.09.09 [17:13]  BitFORCE (ttyUSB0) ERROR: Unexpected response to work results poll command: BitForce SHA256 SC 1.0
2013.09.09 [17:13]  BitFORCE (ttyUSB0) ERROR: Unexpected response to temperature check command: INPROCESS:1
2013.09.09 [17:13]  BitFORCE (ttyUSB0) ERROR: Unexpected response to temperature check command: COUNT:16
2013.09.09 [17:13]  BitFORCE (ttyUSB0) ERROR: Unexpected response to temperature check command: 283DF32FA7E2E8C4E19BFDFC0E59355142FF2A3B01C658891AD9D0743EEA14A2,B7C23A1A522DE58E1931679C,5,1,6BC1B0FE
2013.09.09 [17:13]  BitFORCE (ttyUSB0) ERROR: Unexpected response to work queue flush command: 283DF32FA7E2E8C4E19BFDFC0E59355142FF2A3B01C658891AD9D0743EEA14A2,B7C23A1A522DE5981931679C,2,3,1B251CAF,28F291D5,B0A3BE86
2013.09.09 [17:13]  BitFORCE (ttyUSB0) ERROR: Unexpected response to queue job pack command: 283DF32FA7E2E8C4E19BFDFC0E59355142FF2A3B01C658891AD9D0743EEA14A2,B7C23A1A522DE59D1931679C,0,2,66804588,851B4256
2013.09.09 [17:13]  BitFORCE (ttyUSB0) ERROR: Unexpected response to queue job pack command: 283DF32FA7E2E8C4E19BFDFC0E59355142FF2A3B01C658891AD9D0743EEA14A2,B7C23A1A522DE59C1931679C,7,0
2013.09.09 [17:13]  BitFORCE (ttyUSB0) ERROR: Unexpected response to temperature check command: 283DF32FA7E2E8C4E19BFDFC0E59355142FF2A3B01C658891AD9D0743EEA14A2,B7C23A1A522DE5A21931679C,4,0
2013.09.09 [17:13]  BitFORCE (ttyUSB0) ERROR: Unexpected response to temperature check command: 283DF32FA7E2E8C4E19BFDFC0E59355142FF2A3B01C658891AD9D0743EEA14A2,B7C23A1A522DE5AC1931679C,3,1,E9C671B0
2013.09.09 [17:13]  BitFORCE (ttyUSB0) ERROR: Command timed out. Retries: 0
2013.09.09 [17:13]  Probe of port /dev/ttyUSB0 failed: timeout
it stops after ~1-2 hours and is not starting automatically again (exept for starting BitMinter client manually new)
(I have removed the inflow plate because with this it is much louder and stops quickier)
TIA
sr. member
Activity: 406
Merit: 250
September 09, 2013, 07:03:55 AM
#26
Let us keep it simple. Does the unit have temperature sensors? Are they showing better cooling? Are you getting better hashrate?

If you are good enough.

I'd say temperature is the same and power usage is some 2-4W lower
hero member
Activity: 924
Merit: 1000
September 09, 2013, 06:13:37 AM
#25
Let us keep it simple. Does the unit have temperature sensors? Are they showing better cooling? Are you getting better hashrate?

If you are good enough.
hero member
Activity: 651
Merit: 500
September 09, 2013, 05:54:47 AM
#24

Non steady state conditions tell you nothing about the cooling capacity of the system, too many things going on.

And by that you mean? Sorry but english is not my 1st language.
legendary
Activity: 1666
Merit: 1185
dogiecoin.com
September 09, 2013, 05:51:50 AM
#23
we'll see when i get the thermal cam in my hand, we'll see... I only need to figure out how to take pictures so that metal case would not block my "heat view".. I mean, I can't take pics when cover is taken off.. then the air will not tunnel through.. and taking pics with cover on I cant see single component heat.. I can only see heat spots on case.. maybe that is enough though...
Thermal cam won't particularly help. Just look at core temps at a fixed ambient and fan rpm.

as I think I mentioned before, "my design" appear to push out less air, and hashing temp is the same (although reaching same temp takes more time) = less rpm needed to cool to same temp, but that's not all, shutting down miner and starting again show that modified single has cooler starting temp = it must be more efficient as air goes thru single and does not hassel around-up-n-down (also less noisy), now i order to see if everything is cooled and compare original design with my design I was thinkig of takeking thermal images where both are in front of me on the table, and outside (to get bigger contrast of cold/warm).


Non steady state conditions tell you nothing about the cooling capacity of the system, too many things going on.
hero member
Activity: 651
Merit: 500
September 09, 2013, 05:37:22 AM
#22
we'll see when i get the thermal cam in my hand, we'll see... I only need to figure out how to take pictures so that metal case would not block my "heat view".. I mean, I can't take pics when cover is taken off.. then the air will not tunnel through.. and taking pics with cover on I cant see single component heat.. I can only see heat spots on case.. maybe that is enough though...
Thermal cam won't particularly help. Just look at core temps at a fixed ambient and fan rpm.

as I think I mentioned before, "my design" appear to push out less air, and hashing temp is the same (although reaching same temp takes more time) = less rpm needed to cool to same temp, but that's not all, shutting down miner and starting again show that modified single has cooler starting temp = it must be more efficient as air goes thru single and does not hassel around-up-n-down (also less noisy), now i order to see if everything is cooled and compare original design with my design I was thinkig of takeking thermal images where both are in front of me on the table, and outside (to get bigger contrast of cold/warm).

legendary
Activity: 1666
Merit: 1185
dogiecoin.com
September 09, 2013, 05:21:51 AM
#21
we'll see when i get the thermal cam in my hand, we'll see... I only need to figure out how to take pictures so that metal case would not block my "heat view".. I mean, I can't take pics when cover is taken off.. then the air will not tunnel through.. and taking pics with cover on I cant see single component heat.. I can only see heat spots on case.. maybe that is enough though...
Thermal cam won't particularly help. Just look at core temps at a fixed ambient and fan rpm.
hero member
Activity: 651
Merit: 500
September 09, 2013, 03:56:38 AM
#20
we'll see when i get the thermal cam in my hand, we'll see... I only need to figure out how to take pictures so that metal case would not block my "heat view".. I mean, I can't take pics when cover is taken off.. then the air will not tunnel through.. and taking pics with cover on I cant see single component heat.. I can only see heat spots on case.. maybe that is enough though...
hero member
Activity: 924
Merit: 1000
September 09, 2013, 03:15:21 AM
#19
If it works great job.



Guessing the venturi effect is helping move that heat away nicely.
*Around the heatsink through the massive 0 resistance gap, yup. No way that is cooling better than before.

Evidence to support your theory it doesn't work, possibly some models or math to prove that?

Basically calling the guy a liar, I am pretty much inclined to give him the benefit of the doubt at this point given the inelegant solution that was devised by BFL in the first place. Time for some numbers and proof cause dogie is calling you out eestimees.
legendary
Activity: 1666
Merit: 1185
dogiecoin.com
September 09, 2013, 03:10:00 AM
#18
If it works great job.



Guessing the venturi effect is helping move that heat away nicely.
*Around the heatsink through the massive 0 resistance gap, yup. No way that is cooling better than before.
hero member
Activity: 924
Merit: 1000
September 09, 2013, 02:17:46 AM
#17
If it works great job.



Guessing the venturi effect is helping move that heat away nicely.
hero member
Activity: 651
Merit: 500
September 09, 2013, 01:15:07 AM
#16
here it is



and still i'm pretty sure it is not only quieter but efficient too. still thermal imaging to be done to measure temp under the board and so.
legendary
Activity: 1666
Merit: 1185
dogiecoin.com
September 08, 2013, 12:26:36 PM
#15
Got my singles, today i moded one as i described, and it feels to me that it is more efficient. They are both side by side, hashing 61-63C. When i stop miner and start again, the modded single temp is much lower than original cooling setup. Within few minutes, they both are at the same temp again, but it feels like modded one's airflow is ligther = fans rotating slower.

Tomorrow i upload some pics of how i did it. I will try to get something to measure airflow and friend said he can borrow thermal cam to take pics.
tldr: You won't be able to get anything that measures airflow to any meaningful precision, unless you have a venturi arrangement.
hero member
Activity: 651
Merit: 500
September 08, 2013, 08:03:17 AM
#14
Got my singles, today i moded one as i described, and it feels to me that it is more efficient. They are both side by side, hashing 61-63C. When i stop miner and start again, the modded single temp is much lower than original cooling setup. Within few minutes, they both are at the same temp again, but it feels like modded one's airflow is ligther = fans rotating slower.

Tomorrow i upload some pics of how i did it. I will try to get something to measure airflow and friend said he can borrow thermal cam to take pics.
legendary
Activity: 1666
Merit: 1185
dogiecoin.com
September 02, 2013, 07:55:00 PM
#13
Cooling is much better when blowing through rather than sucking through a heatsink. As others have said, it takes a worse path when sucking through. This is because the pressure profile on either side of the fan isn't the same, its much stronger and compact on the blowing side.

Additionally, the rest of the PCB and components need airflow that a sucking arrangement wouldn't provide.
hero member
Activity: 672
Merit: 500
September 02, 2013, 03:21:19 PM
#12
I have 4 Jalapenos, and I arrange them in a stack of 2 open case (so two stacks, one on top of each other). If I leave it the way it is, it runs about 40C, if i put two fans next to them in a push pull manner, they drop 6C to about 34... So the two fans do make a difference believe it or not.. Also the push pull config fans are pointed in the direction of the heatsink grooves..

sr. member
Activity: 280
Merit: 250
Hell?
September 02, 2013, 03:06:20 PM
#11
the small fans blow UP not down.

i have a single, and this is how it works.
legendary
Activity: 952
Merit: 1000
September 02, 2013, 02:47:38 PM
#10


Problem: The 2 smaller fans don't blow down. They blow up, IIRC. People who have been running them out of their case have been reversing the direction so the fans blow down.

I feel like it's an interesting idea, but IDK how well it will work. The heatsink has a significant gap between the actual chip and the heatsink itself, so I don't feel it would be completely effective.

I've actually heard that the noise can be cut down significantly by running it outside of it's case, and with 2 quieter fans replacing the heatsink fans, but blowing down.

Still, you've got to remember: dissipating 200+Watts of heat is not an easy thing to do, although I do feel that 4 fans is a big overkill.
legendary
Activity: 1190
Merit: 1000
September 02, 2013, 02:20:13 PM
#9
I think the best solution for sound here is remove the case and all fans, then place 2 singles next to eachother and put one big fan on top that covers all 4 heatsinks. Also why are all top mounted fans blowing DOWN?? Heat naturally goes UP!!
The heat will go naturally up... the fins of the heat sink.  The narrowness of the fins combined with their height gives a lot of surface area for the radiation of heat off of the fins.  Many Jalapeno owners have already stated that the stock position of the fan (blowing up, thereby pulling air through the fins) results in the system running several degrees hotter than if the fan is blowing down into the fins.  It is much easier to get a uniform airlfow by pushing air than by pulling it. 

When pulling air through a fan, it will take the path of least resistance into the fan. Thus it will not flow over the entire surface of the heat sink fins, but instead flow in along the top. Using the fan to push, thereby forcing air all the way down into every crevice of the heat sink creates airflow along the entire surface area of the heat sink which increases the amount of heat that can be transferred away.
hero member
Activity: 532
Merit: 500
September 02, 2013, 08:32:31 AM
#8
I think the best solution for sound here is remove the case and all fans, then place 2 singles next to eachother and put one big fan on top that covers all 4 heatsinks. Also why are all top mounted fans blowing DOWN?? Heat naturally goes UP!!
The heat will go naturally up... the fins of the heat sink.  The narrowness of the fins combined with their height gives a lot of surface area for the radiation of heat off of the fins.  Many Jalapeno owners have already stated that the stock position of the fan (blowing up, thereby pulling air through the fins) results in the system running several degrees hotter than if the fan is blowing down into the fins.  It is much easier to get a uniform airlfow by pushing air than by pulling it. 
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