Topic: Butterfly Labs - Bitforce Single and Mini Rig Box - page 3. (Read 186944 times)

http://en.wikipedia.org/wiki/Cryptographic_nonce

Is that anything like noncense?

What does a nonce mean?

Ignore my post count

The BFL wastes 1/2 a nonce range per LP due to it's design
(ignoring listening to bitcointalk people before they made it)

Basically, when you send it work, it wont give you back an answer until it finishes the work.
On the 832MH/s bitstream that's 5.162 seconds of silence.

But ... if the LP comes during the 5.162 seconds, you have a problem:
1) Either abort the work and start new work (with no results)
2) Let the work complete and thus have stale results.

For the vast majority of pools 1) is best - that's how cgminer works.
Thus on average you will throw away half a nonce per LP.
i.e. on average 2.581 seconds of processing per LP, now since an LP is on average 600 seconds, that's 0.43%
832MH/s * 0.43% is ... 3.58MH/s ... so you should expect to get 828.5MH/s maximum if you get no stale/rejected shares due to the pool.

There is also another < 1MH/s in there due to the network speed increasing - I worked it out before in the cgminer thread for someone and for him it was 0.4MH/s on a faster bitstream:
https://bitcointalksearch.org/topic/m.1135726

But wait - you are also getting rejected shares - 1314/98395 - another 1.34% - and rejected shares don't count either, so that's another 11.2MH/s - so you are now down to 817.3MH/s which is very close to your numbers.

So the biggest loss in there is actually via your pool.

I get 0.35% on OzCoin with my BFL ... averaging 870MH/s or higher with the 880MH/s bitstream.

I'll let them be then 

Looks just the same as all mine do. 

Is it normal for BFL singles to run about 1 iteration below their firmware speed? The top one is on running the 864 firmware, bottom three are 832. No throttling, but averages seem well below the advertised firmware speed. Never really paid much attention before, but trying to eek out every last mhash with the recent difficulty increases.

Try removing the case, and powerping it up. If it still makes a noise, then my solution will not fix it because the noise is caused by something else.

Sounds like a bad bearing.

Upon further inspection the problem does lie with the bottom fan. It appears the middle of it is not even... When you look at the middle of it while it is running you can see it wobbling... mrb, will your solution fix the fan's center itself wobbling? Thanks!

Or insert screw washers: https://bitcointalksearch.org/topic/how-to-fix-rattling-fan-noise-on-bfl-single-96165

Thanks for the info! What would the turnaround time look like for sending it to you to fix? If I forget/place in wrong one or two of those rubber washers, that won't affect trade-in value, right?

What is the amperage draw (& cfm maybe) of your stock 92mm fans??? So we can match them accordingly.

Thanks  

The top fan is a standard 92mm fan running at 2,500 rpm.  If you're having trouble with it, you can either send it in to us for replacement or swap it on your own.  Doing this sort of work is straight forward, but please be careful not to shock the board.  Power everything down before you open the case.  Unless obvious mishandling is responsible, simplly opening the case and swapping the fan will not void the warranty or alter it's trade in value.

If your unit is making a noise, that is much more likely to be the smaller underside fan which is either copper or silver in color (depending on your unit).  You can try loosening the lower screws to relieve pressure on the fan...   or just try setting your Single on it's side...  that will almost always arrest any unwanted sound.

One of my singles has a top fan that seems like its slightly unbalanced or something. It runs hotter than the rest and has a vibration to it when I hold it while none of the others do. I'd be interested in the same answer. I think I could find a fan locally. Any particular specs for it?

Thanks

Hey BFL, my single's fan is making really annoying noises that don't sound good... Will replacing the fan void my warranty/ability to trade-in for the SuperComputer Single I bought? If I am allowed to replace the fan, any one in particular you would recommend? (Right power draw, etc.). Thanks!

Problem is that temps change with the bitstream you use. The 120mm fan from the side is making the main difference. About 3 to 4 degree C less.

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The temps are lower with the extra fan. I also turned the top fan around.
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Top fan blowing down should be more effective I believe, any guess on the difference in degrees ?

Yeah right. And guys like you and Vladimir are only here to save the dumb damn hypocrites...

Not sure if serious or trolling. 

I need more mini rigs to run Gigamining. Pure and simple.