Swedish ASIC miner company kncminer.com

[Phoenix1969]

this "higher temp =  higher performance" doesnt make a lot of sense. Design aside, there are only two factors affecting performance:
- clockspeed. Is this variable on KnC? Can it be measured?
- number of functional cores/ % of HW errors. Does this go down as temps go up?

Thats it. The rest is statistical noise.

well believe it or not, my Saturn actually runs better warmer....maybe with heat things expand, and as some have said in earlier posting, maybe that help "seat" chip better, maybe heat make solder melt/soften and chip makes better contact.....

all I know is that slightly warmer has actually produced slightly better numbers.....fwiw

They are in denial because it doesnt make sense,,, lol  But it's the truth. Mine are still rockin' solid now, no drastic drop overnight this time.
It may not be this way for everybody, but the higher temps cured both ailing saturns, point blank.

I also noticed that the coldest sat is the slowest although I'm tickled with the speed

[elasticband]

just tried .97 firware, got a nice hashrate and low HW rate, but the fans were not spinning   73c on one core. reverted back. WTF KNC?

After reverting back, the two fans at the front of the case do not function!!!!

[xyzzy099]

this "higher temp =  higher performance" doesnt make a lot of sense. Design aside, there are only two factors affecting performance:
- clockspeed. Is this variable on KnC? Can it be measured?
- number of functional cores/ % of HW errors. Does this go down as temps go up?

Thats it. The rest is statistical noise.

sense or not. i have one jupiter that reacts in the same way. additional cooling with a big box-fan on top of the miner = cgminer crashes every 5 min. without box-fan = cgminer stable / higher avg GH.

Can it be electrical interference from the fan's motor? They have quite a strong electromagnetic field when running.

It's probably a effect called temperature inversion. 28nm logic gets faster with higher temperatures.
http://siliconsaint.blogspot.com/2012/07/temperature-inversion-in-deep-sub.html?m=1

I don't think so...  That phenomenon might make it possible to clock a chip faster at a higher temperature, but it should not effect the speed of a chip that is clocked at a constant speed.  Right?  I mean, if I am reading it right, the rise-times and fall-times on the edges will be faster, but I don't think these chips are clocked close to theoretical maximum where that might make a real difference.

[Phoenix1969]

this "higher temp =  higher performance" doesnt make a lot of sense. Design aside, there are only two factors affecting performance:
- clockspeed. Is this variable on KnC? Can it be measured?
- number of functional cores/ % of HW errors. Does this go down as temps go up?

Thats it. The rest is statistical noise.

sense or not. i have one jupiter that reacts in the same way. additional cooling with a big box-fan on top of the miner = cgminer crashes every 5 min. without box-fan = cgminer stable / higher avg GH.

Can it be electrical interference from the fan's motor? They have quite a strong electromagnetic field when running.

It's probably a effect called temperature inversion. 28nm logic gets faster with higher temperatures.
http://siliconsaint.blogspot.com/2012/07/temperature-inversion-in-deep-sub.html?m=1

I don't think so...  That phenomenon might make it possible to clock a chip faster at a higher temperature, but it should not effect the speed of a chip that is clocked at a constant speed.  Right?

I honestly think it's a VRM thing... not an asic thing..  
But the temperature inversion link says it all! wow...

[sbfree]

this "higher temp =  higher performance" doesnt make a lot of sense. Design aside, there are only two factors affecting performance:
- clockspeed. Is this variable on KnC? Can it be measured?
- number of functional cores/ % of HW errors. Does this go down as temps go up?

Thats it. The rest is statistical noise.

sense or not. i have one jupiter that reacts in the same way. additional cooling with a big box-fan on top of the miner = cgminer crashes every 5 min. without box-fan = cgminer stable / higher avg GH.

Can it be electrical interference from the fan's motor? They have quite a strong electromagnetic field when running.

It's probably a effect called temperature inversion. 28nm logic gets faster with higher temperatures.
http://siliconsaint.blogspot.com/2012/07/temperature-inversion-in-deep-sub.html?m=1

Learn a new thing everyday, thanks hypermega for that nice find.

[Its About Sharing]

Seems the Jupiter that I am in a Group Buy with (Aug 2nd order) just arrived last week and is hashing at 315Ghash/s. Looks like a chip is bad or the like.

Any good stories out there of KNC shipping out a replacement board or the like and not asking for the unit back with an RMA and such?

Thanks,
IAS

Crypto_Cumbrian got a RMA for three of his boards :
https://asktom.cf/index.php?topic=170332.msg3393672#msg3393672
https://asktom.cf/index.php?topic=170332.msg3378206#msg3378206
https://asktom.cf/index.php?topic=170332.msg3381036#msg3381036


Edit : He received is new boards : https://asktom.cf/index.php?topic=170332.msg3408979#msg3408979

Thanks for the reply. Any good stories?

[xyzzy099]

this "higher temp =  higher performance" doesnt make a lot of sense. Design aside, there are only two factors affecting performance:
- clockspeed. Is this variable on KnC? Can it be measured?
- number of functional cores/ % of HW errors. Does this go down as temps go up?

Thats it. The rest is statistical noise.

sense or not. i have one jupiter that reacts in the same way. additional cooling with a big box-fan on top of the miner = cgminer crashes every 5 min. without box-fan = cgminer stable / higher avg GH.

Can it be electrical interference from the fan's motor? They have quite a strong electromagnetic field when running.

It's probably a effect called temperature inversion. 28nm logic gets faster with higher temperatures.
http://siliconsaint.blogspot.com/2012/07/temperature-inversion-in-deep-sub.html?m=1

I don't think so...  That phenomenon might make it possible to clock a chip faster at a higher temperature, but it should not effect the speed of a chip that is clocked at a constant speed.  Right?

I honestly think it's a VRM thing... not an asic thing.. 

I would think that as long as the voltage from the VRM is above the chip's lower operating threshold, it should not make any difference, unless they are being overclocked heavily.

[sbfree]

Thought I would share this and maybe some here can even update it with new retailers....

http://coinmap.org/

[Phoenix1969]

I would think that as long as the voltage from the VRM is above the chip's lower operating threshold, it should not make any difference, unless they are being overclocked heavily.

The temp inversion article has me sold on it that 28nm chips run better a bit warm

[HyperMega]

this "higher temp =  higher performance" doesnt make a lot of sense. Design aside, there are only two factors affecting performance:
- clockspeed. Is this variable on KnC? Can it be measured?
- number of functional cores/ % of HW errors. Does this go down as temps go up?

Thats it. The rest is statistical noise.

sense or not. i have one jupiter that reacts in the same way. additional cooling with a big box-fan on top of the miner = cgminer crashes every 5 min. without box-fan = cgminer stable / higher avg GH.

Can it be electrical interference from the fan's motor? They have quite a strong electromagnetic field when running.

It's probably a effect called temperature inversion. 28nm logic gets faster with higher temperatures.
http://siliconsaint.blogspot.com/2012/07/temperature-inversion-in-deep-sub.html?m=1

I don't think so...  That phenomenon might make it possible to clock a chip faster at a higher temperature, but it should not effect the speed of a chip that is clocked at a constant speed.  Right?

Not if the actual speed is already at the edge for the selected core supply voltage. In this case hardware errors can be caused by timing violations. Higher temperature, less timing violations, less hardware errors/crashs.

[sbfree]

this "higher temp =  higher performance" doesnt make a lot of sense. Design aside, there are only two factors affecting performance:
- clockspeed. Is this variable on KnC? Can it be measured?
- number of functional cores/ % of HW errors. Does this go down as temps go up?

Thats it. The rest is statistical noise.

sense or not. i have one jupiter that reacts in the same way. additional cooling with a big box-fan on top of the miner = cgminer crashes every 5 min. without box-fan = cgminer stable / higher avg GH.

Can it be electrical interference from the fan's motor? They have quite a strong electromagnetic field when running.

It's probably a effect called temperature inversion. 28nm logic gets faster with higher temperatures.
http://siliconsaint.blogspot.com/2012/07/temperature-inversion-in-deep-sub.html?m=1

I don't think so...  That phenomenon might make it possible to clock a chip faster at a higher temperature, but it should not effect the speed of a chip that is clocked at a constant speed.  Right?

I honestly think it's a VRM thing... not an asic thing..  

I would think that as long as the voltage from the VRM is above the chip's lower operating threshold, it should not make any difference, unless they are being overclocked heavily.

could it be that the VRMs operate more efficiently at slightly higher temps and automatically provide slighlty higher amps without software/firmware instruction to do so....I do notice that the under performing chip has 2 cores with lower output volt. and current.....and that actually changes just by running the a/c and/or turning it off

p.s. saturn is on a apc ups, so can't be wall flucs

[Phoenix1969]

Yeah, I noticed all this when looking at my graph on eligius, and correlating speeds with time of day & temps. It only took a few minutes to tell the fan was causing problems... the rest is history
In fact, the machines may be overcooled.
The results are undeniable.

[felix64]

Good point, thanks.

I asked Liam over the phone and he told me max temp for the ASIC chips is 105C, so you are far from the point where they are overheating

[xyzzy099]

this "higher temp =  higher performance" doesnt make a lot of sense. Design aside, there are only two factors affecting performance:
- clockspeed. Is this variable on KnC? Can it be measured?
- number of functional cores/ % of HW errors. Does this go down as temps go up?

Thats it. The rest is statistical noise.

sense or not. i have one jupiter that reacts in the same way. additional cooling with a big box-fan on top of the miner = cgminer crashes every 5 min. without box-fan = cgminer stable / higher avg GH.

Can it be electrical interference from the fan's motor? They have quite a strong electromagnetic field when running.

It's probably a effect called temperature inversion. 28nm logic gets faster with higher temperatures.
http://siliconsaint.blogspot.com/2012/07/temperature-inversion-in-deep-sub.html?m=1

I don't think so...  That phenomenon might make it possible to clock a chip faster at a higher temperature, but it should not effect the speed of a chip that is clocked at a constant speed.  Right?

Not if the actual speed is already at the edge for the selected core supply voltage. In this case hardware errors can be caused by timing violations. Higher temperature, less timing violations, less hardware errors/crashs.

That's a valid point, but these chips are running at 45-50C for the most part.  They don't seem to be overclocked or stressed at all.

I guess I got lucky - my Saturn runs on all cores all the time - and I can vary the temperature over a pretty broad range by blowing hot air into the case with an old hair dryer, and I don't see any significant variation in hash rate.  Rock solid at 284.5 GH/s for the last 12 hours or more.  Haven't really tried any specific extra cooling.

That being said, I don't think it's impossible that whatever defect it is that makes the bad chips bad could be something that reacts to temperature.  I just don't think the phenomena is explained by temperature inversion.

[DigginDeep]

I Also found that keeping them warm has made a huge improvement for me.   Last few nights i would wake up in the morning to find nice low temps in the mid 30c's but hasrate went down to around 538 or so  and hardware errors would  be over 11%  Then the hash rate on btcguild would end up in the low 400s ever morning.   So every morning i would start to re flash back to 95 and messing with enable cores and what not.  Keep messing with it.  And always seem around noon or so i would get it running better.  usually around  548 with around 9.9 error rate, and btcguild would show around 490 -505  So yesterday i deiced  to shut the door of the room the miner was in not letting the cool air come in from the night.    And this morning temps where around 44-52c depending on the board.  Hash rate is at 552 and erros down to 7.7% BTC quild showed 534 this morning.   And only two cores are off on one asic and all the other are 100% on   and before this i would have a total of between 6-8 cores off.  

So i don't care what anyone says.  I know for a fact mine runs allot better at a warmer temperature.

[xyzzy099]

this "higher temp =  higher performance" doesnt make a lot of sense. Design aside, there are only two factors affecting performance:
- clockspeed. Is this variable on KnC? Can it be measured?
- number of functional cores/ % of HW errors. Does this go down as temps go up?

Thats it. The rest is statistical noise.

sense or not. i have one jupiter that reacts in the same way. additional cooling with a big box-fan on top of the miner = cgminer crashes every 5 min. without box-fan = cgminer stable / higher avg GH.

Can it be electrical interference from the fan's motor? They have quite a strong electromagnetic field when running.

It's probably a effect called temperature inversion. 28nm logic gets faster with higher temperatures.
http://siliconsaint.blogspot.com/2012/07/temperature-inversion-in-deep-sub.html?m=1

I don't think so...  That phenomenon might make it possible to clock a chip faster at a higher temperature, but it should not effect the speed of a chip that is clocked at a constant speed.  Right?

I honestly think it's a VRM thing... not an asic thing..  

I would think that as long as the voltage from the VRM is above the chip's lower operating threshold, it should not make any difference, unless they are being overclocked heavily.

could it be that the VRMs operate more efficiently at slightly higher temps and automatically provide slighlty higher amps without software/firmware instruction to do so....I do notice that the under performing chip has 2 cores with lower output volt. and current.....and that actually changes just by running the a/c and/or turning it off

p.s. saturn is on a apc ups, so can't be wall flucs

The purpose of a voltage regulator is to provide a constant voltage at any current drawn by the device it is powering, within it's rated limits.  The actual amount of current that flows is determined by the device it is driving, not the regulator.  Changing the amount of current the regulator is capable of providing when it is not near its limits would have no effect on operation.

[elasticband]

i like this bit  :

KnCMiner products are carefully engineered and are not designed to be user serviceable in hardware or software other than when specifically directed by a member of the KncMiner team.
You will invalidate your product warranty if you try to disassemble any of the hardware or software, tamper with the running software in memory or otherwise, attempt to under or over-clock the device or interfere in anyway that is in contradiction to the intended use of the product.
Any performance altering changes to the hardware or software are logged/stored and will be used to validate any warranty claims

[Phoenix1969]

283 is awesome...don't touch a thing!   BAM
again, i saw the asic 28nm article hypermega posted....   pretty much explains it.
http://siliconsaint.blogspot.com/2012/07/temperature-inversion-in-deep-sub.html?m=1

[opentoe]

Yea, the graphs and things are cool like I said, but having no idea when I would be getting paid or what my 24 hour return is (if I'm making money or not) is a weird way to hash. At least with BTC they show you right on your stats page what you are making within a 24hour period, payout info, all the necessary info there is. Eligius is more of a guess right now, no? Also, if I wanted a manual payout with Eligius I can't because they don't have it. Bitcoin raised up to $201 yesterday and I wanted to sell a few bitcoin so I did a manual payout with BTCGuild, could I have done that with Eligius or would I have to wait 3 weeks until their payout schedule catches up or whatever? Yea, confusing at the least. I guess that's where the BTC fee comes in. You are furnished with all the appropriate information almost on one page.

you just 25*(Hashrate/2^32)/difficulty  (that's per second)

You get 25 bitcoins in a block
in order to find a block, you need to hash (on average) n diff1 shares, where n is the difficulty
in order to find a diff1 share, you need to calculate (on average) 2^32  hashes.  

2^32 = the number of bytes in a 4 gigabytes.

Alternatively, you can just go look at the PPS rate on btcguild, and assume you'll be getting a few % more then that.

That's the thing here....we are using computers that can do millions of calculations a second, I don't really want or think it is necessary for us to do math anymore when we have the best invention in the world that does it perfectly. Yea, I know...some of you still prefer to do your own calculations and expect everyone else to....but if I have a computer I kind of expect it to do all the math it can for me. I know, I know, that's why we are all dumb and stupid now. I would have just figured a mining pool would have all the important/critical info right available to the user instantly. I still couldn't figure out Eligius's payout schedule/process (yea, I guess I'm an ididot) so I went back to the Guild where I can at least input the amount of BTC I want to auto pay out. I know wizkid is doing his best, but when I see literally wizkid's name in the URL itself I have to chuckle a little. The main reason why I wanted to switch to Eligius anyway was I got very good hash rates there and no fees.

[xyzzy099]

I went back to the Guild where I can at least input the amount of BTC I want to auto pay out

You can do that on Eligius too.  It's settable from your 'My Eligius' page.