BFL Bitforce 60GH/s miners

[j68r]

Hello folks,

First time I've asked tech questions here so please be gentle. Apologies if these are dumb and have been asked hundreds of times but hope you can help.

Is there any collective wisdom on what the best fans are to replace the stock fans in the BFL Single SC? These four units are very, very loud, I had to put them in the loft and stand them on a thick bubble wrap padded platform to quiet them.

I have two noctua NF-S12A FLX (DC12V - 1.44W - 0.12A) for one box and looking for some reassurance these won't just make it start smoking when fitted.

I also want to take the heat sink off and clean, then use some paste on there. Is that generally a good or bad idea? I'm quite comfortable around computer hardware but obviously don't want to go diving in if there is something I ought to be aware of beforehand.

As it stands the units are all working but i had some major problems with BFLminer and them not working properly after an hour or two. I've since been using the bitminter client and they seem a lot happier.

Is it normal to see the hash rate bouncing around from between 180 to 300 on four BFL single SC's ? It's stable around 210-240 a lot of the time but does bounce around (this in bitminter client)

If anyone can help or point me to a thread that will that'd be grand

thanks
J

edit: I also have them linked to this PC via a 12m USB repeater cable. That might have some effect too?

[vm1990]

Hello folks,

First time I've asked tech questions here so please be gentle. Apologies if these are dumb and have been asked hundreds of times but hope you can help.

Is there any collective wisdom on what the best fans are to replace the stock fans in the BFL Single SC? These four units are very, very loud, I had to put them in the loft and stand them on a thick bubble wrap padded platform to quiet them.

I have two noctua NF-S12A FLX (DC12V - 1.44W - 0.12A) for one box and looking for some reassurance these won't just make it start smoking when fitted.

I also want to take the heat sink off and clean, then use some paste on there. Is that generally a good or bad idea? I'm quite comfortable around computer hardware but obviously don't want to go diving in if there is something I ought to be aware of beforehand.

As it stands the units are all working but i had some major problems with BFLminer and them not working properly after an hour or two. I've since been using the bitminter client and they seem a lot happier.

Is it normal to see the hash rate bouncing around from between 180 to 300 on four BFL single SC's ? It's stable around 210-240 a lot of the time but does bounce around (this in bitminter client)

If anyone can help or point me to a thread that will that'd be grand

thanks

J

edit: I also have them linked to this PC via a 12m USB repeater cable. That might have some effect too?

The fans should be good for it (hard to go wrong with fans) aslong as there the same voltage 12v and the amps arnt more than 1 or 2 amps out (dosnt matter if you use a ATX PSU)

the 12m cable is a very bad idea as its right on the maximum USB cables support and start to drop errors with the length. if you wanted to do that sort of idea have a look around on the web and you cn get some USB to Ethernet adapters (probably better to get powered ones) which will be good for 300 or so meters

the important thing with the fans is the amount of air they move. the more expensive fans get a good balance between air flow and noise so dont go to cheap about £10 for a fan is a good area. the fans youve got should be a big improvement (BFL fans probably cost best part of £2

if you want to change thermal paste id strongly recommend you pick very very carfully and DO NOT use things like Artic Silver. its a conductive paste and with multiple small chips under each heatsink it could short out he chips and blow the whole units. id recommend a good paste thats no conductive and that isnt to runny (otherwise its just going to run between the chips and not do anything useful)

iv used Arctic Cooling MX-4 on everything from PS3 to XBOX360 and all my overclocked computers and GPUS its very good for a cheap price and will keep close to Arctic Silver

[j68r]

So I fitted the two noctua NF-S12A FLX (DC12V - 1.44W - 0.12A) fans today and the flippin temperature has gone up!! by about 5C so I can only assume they're not pushing nearly enough air. Presumably 1.44W is too weak.

with the case off the unit was reporting 65-66C now with fans in its gone up to 71C

It may be that the top fans are pushing more air out of both ends than the two noctua end fans can move. I've made sure one is pushing and the other pulling so it isn't that causing the temperature issue. By contrast the other 3 miners running alongside are a good 15C cooler which is frustrating because fitting them was a royal pain. They're all in a cold loft space at the moment.

Can anyone suggest any specific 120mm fan replacements that are good for these SGL600G units?

much appreciated

[j68r]

Fitted a pair of corsair SP120's today. Only things I could get hold of at short notice.

Still haven't refitted the outer case, so the fans are still "outside" but the temps have dropped by about 8C which has brought them in line with the other 3 now and provides a bit more comfort to my paranoia. I understand the lower side of the main pcb needs an airflow stream. I think whats possibly happening with the case on for the wind tunnel effect is that the top fans are moving so much air the end fans cant direct it and the result is that the front fan effectively gets slowed down by the air pushed out by the tops fans (and the horrible stock grills of course) - sound plausible?

Anyway as it stands now it's open and working without the temperature differences I was seeing with the cased units.

[-ck]

Noctua fans are designed for quiet operation. While you can get a relatively quieter fan for equivalent flow/pressure to a different fan, it is impossible have both quiet and high performance.

[j68r]

Yeah, I appreciate that relationship. I've tried asking a few times and can't seem to get anyone who knows what spec the stock 120mm fans are (ie how many amps). It's obvious the quieter ~0.1A 120mm fans just aren't moving enough air to boss the smaller 80mm top fans and create a wind tunnel effect in the case (when it's fitted).

Does anyone anywhere have the spec for the stock 120mm fans please?

[-ck]

The actual model is well hidden (bastards). I tried modifying my own firstly with the top fans since they're "thin" fans and figured extra pressure full thickness fans would be better if they were open air and blowing down without the side 120mm fans (to be quieter overall). I discovered the originals were surprisingly high flow and higher pressure lower flow fans did not help one bit (they were actually worse). Then I tried high flow higher pressure and they didn't help either. I've been running them cover off with the top fans blowing up and only the one 120mm fan blowing into it (no pull fan) and that had the greatest effect on improving cooling but wasn't as dramatic as I would have hoped. Even blowing a gale over it, feeling the heatsink it's only ever warm, even when the device sensors are reading 80+ degrees on a stinking hot day here. My final conclusion is the heatpipes aren't dissipating the heat to the heatsink fast enough and blowing harder on the heatsinks was pointless. To get similar flow rate (but higher pressure) on the top fans, I ended up using adda fans that were .45A if that gives you a ballpark for how much current they're drawing, so I expect the 120mm fans are drawing a lot more than .1A.

[j68r]

Really useful info that, very much appreciated.

I've only had these a short time and looking to move them on asap, supposedly got a buyer but I'm half expecting a knock back after the volatility today.

If they'd been mine 6 months ago (if only, if only) I'd have them all running off ATX psu's and done some serious experimenting with cooling but as it is I'm loathed to do anything beyond fiddling with end fans on the one unit without a cover.

thanks again though, I had figured soon after fitting both the noctua and corsair fans that the stock fans must be drawing a hell of a lot more current, oh well that's someone else's headache now.. if they turn up.

It seems the critical role of the end fans is to create that cooling air stream between the base board and the underneath of the mainboard, to that end these quieter fans seem to do the trick with the stock top fans left blowing up (all uncased of course)

It's only when I refit the case the whole endeavour fails.