Topic: My review of Avalon 841 . - page 2. (Read 19343 times)

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ok, I opened the miner and did a good dust clean up with compressed air.

now it's showing 28/75 but still a fan running at 100%  

http://www.delta-fan.com/subcategory.aspx?id=17

the original is 210CFM at 6000rpm.

this one 190CFM at 4500.

if you multiply 4500 by 1.35 you're just above 6000 and that would give a theoretical 256CFM (190*1.35)
so it 'seems' to perform better airflow wise.

I can't seem to find it in europe so I'll have to order it in the US so that will take a while before I can test it (if I order it).

Maybe, but 191 CFM seems weak though. Most likely that is at max power? Try the fan let us know.

I don't think that lower rpm always means being worse. better blade placement can lead to better airflow at lower rpms.

I placed it in a server rack with those perforated doors on it.

But it doesn't seem to drop below 29C so it's alternating between 5700-5800 rpm which is still near 100%.

I have to admit that the pull in side is aimed to the pull out of another rack 1.5m in front of it.
Maybe it pulls in warm air from that rack.

I'll rotate it 180 degrees maybe that makes the temp. drop more as there is no heat on that side and the airco is above that area.

4500 rpm is under spec, you're db's will be lower but the temp in the unit will likely increase at 100% an speed.

Some cheap sound foam will still help if there is a lot of acoustic reflection. Just speculating at this point.

thanks for those who pointed at the usage of the none "-offset" method.

using the -offset method with 0, -1 or -2 always ended with a steady 13Th.

without the -offset it actually seems to work to tweak the speed.

-2 ~9.600Th
-1 ~10.950Th
0 ~12.500Th

the miner is currently in a garden cabine/shed so the fan is at 100% (36/77) because it's a late summer day
so it gets quite warm inthere but as there is a lot of wind I left the door open and let it blow throught the door.
last night it was also at 100% speed while the temps were 27/72.

The noise is a lot louder than the 741 due to the 30C (?) max limit.

Is it worth trying to use this fan to lower the noice/wattage?

https://www.parallelminer.com/product/avalon-841-fan-replacement-delta-dx-62-4500-rpm-191-cfm-55-dba-120mm-x-38mm-a821-asic-miner-fan-copy/

the miner will end up in a small 20C air conditioned room so it should be less loud than now but any DBs lower is always nice.

Try to set the voltage offset to -1 or -2. See my review/guide for details. The link is in my signature space.

hi,

What is best efficiency/hash setting for the 841?
Thought it was a bit better as the bitmain..

Glad you did, not sure how but I missed how far you went with the underclocking.

I haven't gone any further than -2, so far the heat hasn't called for it but nice to know the options available.

bump as it make referral to the 851 thread easy

when set to lower voltage numbers gear runs okay at 95f

If your gear is not working at 20c  

you have:
 bad unit:
 bad psu
 or you set voltage too high 0 or +1

none of us had issues at 20c

Maybe a bug got stuck in the gear.

Well this is working out well....
Today just got another A841 in from Blockforge, also was able to add my last of 6 741's to the main farm and wadda ya know... One of my T9's has a board that went titsup so took it offline. Worse is that a batch-11 s9 I have as a 'spare' seems to want to run hotter than the hubs of hell, lord knows what the power draw is. Even underclocked to 533 temps are still around 100-105C.
Woof. All in the timing I guess
Anywho, good timing for the A8 to arrive! Taking the hot s9 back offline and replacing with the 841. Keep this up and soon most of my farm with be Avalons

Top Man!

Thanks for the proof of concept, I tried replicating your test, similar results.  I guess its best to leave on default(--avalon8-voltage-level-offset 0), I get roughly 13700 @ 21/65 and 13550 @19/66 for the other 841.

Thank you very much

I have yet to try over clock modes.

I simply don't  have the cooling available.

I know that  in a 67f room  which I can't do again until it gets cold outside  I got my best results

I am pretty sure   in a 60f room  you can do an overclock and get 14th with good numbers
I am certain in a 50f room  you can do an overclock and gt 14.2 th with good numbers.

But I can't create that environment unit the fall.

there have to be some people with a good psu  that will do 2400 watts such as the delta sold by parallel miner
or the hp 2450 watt psu that can do a solid over clock in a cool room.

EDIT  it is mom's day and I guess ogombil's mom wants some numbers for overclock
we had a t-storm and this morning it is 55f so I am doing some overclock

i did not get above 13900 using  any setting

my best was

watts 1414
hash 13900
temp© 20/69

on --avalon8-voltage-level-offset +1

note to be sure I had lots of psu overhead I did 2 bitmain apw3++ which were using 240 volts and 1414 watts since they can provide close to 3000 volts I had lots of overhead.

Hi,

Thanks for sharing, do you any tests on the safest overclock settings suitable for situations where heat is not an issue nor electricity costs?

Thanks.

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Moderator's note: This post was edited by frodocooper to remove an unnecessary quote.

I got some more avalon 841 in and a sorcerer psu  and will do a few tests with them.

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watts 1279
hash  12654
temp © 32/72
fans  100%

room temp 82f

but gear is near an ac vent which highs to cool off gear.

more options setting is below
--avalon8-voltage-level -1

time of test is 1h 24m 53s

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More Options setting of next test is
--avalon8-voltage-level -5

this is the lowest test I have tried to date
watts 1012
hash ---------waiting for hash rate to settle in
temp © 30/67
fans 81%
room temp 82f

time will do at least 1 hr

the - 5  setting seems to be as low as I can clock
full size images



hash 8500
watts 950
temp© 29 / 65
fans 61%
room temp
time  9h 6m 12s



I took some photos of this test bed setup note room is 83f but it is taken on top of a tv setup and reads high.  I placed the psu to get cooling from an ac vent.

watts 950



temp is at 6 foot height about 9 feet away from gear



gear note corsair ax1500i psu



note ac vent which does push some cool air towards psu




8500 using 950 watts is about 0.111 watts a gh the point of tests like this is to show work arounds it means you could use any 1200 watt atx psu in a pinch even with 120 volt power.
it also allows for use in a hot space during the summer.
this gear should not have overheating issues at this setting if you area to mine is fan cooled  and runs warm in the summer  this setting should work for you.


here are the five under clocks  that work for me

--avalon8-voltage-level -1
--avalon8-voltage-level -2
--avalon8-voltage-level -3
--avalon8-voltage-level -4
--avalon8-voltage-level -5   lowest numbers      8500 hash at 950 watts runs very cool


the 2 below did weird shit and acted like overclocks not under clocks
--avalon8-voltage-level -6
--avalon8-voltage-level -8

I typically see approx 1% can be as high as 1.5%, doesn't matter if 841, or 821

The reason is that this number means nothing

For some reason Canaan support told me HW is not hardware errors and that values there don't matter. I have hundreds in 24H period with factory settings.