Topic: Question to multi-BFL Single miners: temperature and throttling issues - page 2. (Read 7028 times)

During throttle, the device does respond to temperature read, status read, etc.
A new job, however, cannot be issued, as the unit will respond with 'BUSY'.


Good Luck,

Been running mine since yesterday. It is warm in this room and cgminer shows the single at 69 - 70 constantly. It hasn't done any type of throttling at all and stays right around 800Mh/s.

Easyminer will allow you to flash different firmware.  The thinking goes that if you reduce the max speed, it will throttle less (or not at all) giving you better overall hashrate.

BFL (Sonny) replied with the same suggestion about it being a loose heatsink
(and a BFL replacement if it wont work properly)

Fortunately for me it seems most likely to have been some sort of "burn in" issue
since once the temperature dropped that night after midnight and it stabilised, it hasn't had any more non-LP throttling since, during the almost 2 days and nights since!
(though maybe that is also due to the temperature here being quite cold for the last two days?)

The non-stop stats for almost 1 day 19 hours has been:
817.3Mh/s (A:29504 R:331 HW:0) U:11.45/m

Sonny also said that they will be releasing their miner soon Quote: "I hope to do so within the next week" (no idea what that really means)
but made no mention of the details of the commands to control the throttling that will be in the new miner
I guess we'll just have to wait until it's released and then get the commands out of the miner
(damn annoying decision that one is)

I still have no idea if the temperature reply from sending the "ZLX" command is related to the temperate used from throttling ...

The two hosts are in 2 'different' environments.
One is here my desktop and the other is down in the underground basement garage that is clearly cooler.

However ...
... and my overnight run shows that it is indeed exactly ambient temperature related.

So although that does sound like a loose heatsink, I'm still wondering why the temp reported is always below 55°C
(I would say below 50°C but it has now got up to 50.x°C and hovering at 49.1°C - it's now 9:45am)

Last night the weather predicted temp was 9°C and BFL running in the basement got the expected average of 815MH/s
Up to an hour before the last time I restarted cgminer (3:30am) it was still throttling
(of course during an LP is expected, but it was also throttling not during an LP)
The fact that the 5s average was pretty much always at 826MH/s before 3:30am (except during LP) suggested to me that it had indeed dropped to whatever temperature it requires to not throttle

So my guess is one of:
1) the throttling process in the BFL is brain dead/faulty in my BFL (hmm I remember saying something about that in the BFL thread - suggesting it be possible to control the throttling - since hardware isn't always perfect - a LONG time ago)
2) the temperature that cgminer gets from the BFL is unrelated to the temperature used to determine throttling
3) the ambient temperature needed for a BFL is not far above a fridge (close to 10°C) and that should be made abundantly clear

Of course 3) could simply be a loose heat sink - but then 2) would also need to be true

Edit: of course I did email BFL about this 13 hours ago so I guess I'll see what they suggest also.

Sorry I meant Kano.

If you mean my setup, no. It's one cgminer instance operating 5 BFL Singles (plus 3 GPUs) with 4 of them running full speed at ~815 with no throttling and the problematic one at ~715 on average, no matter how I try to add external cooling. I'd assume the conductivity from chips to heatsink is problematic, but I'm not going to dismantle it and void warranty unless someone experienced that you can recover a throttling one by e.g. re-applying thermal grease. The heatsink is tightly fixed, BTW.

Wait, so on one instance of cgminer it is slow and on another it is faster? Is it a host system limitation of some kind? Although I doubt that. Did you check to make sure that the heatsink was firmly attached? There have been reports of it dislodging during shipping.

My throttling device's front LED toggles for around two seconds every 3 minutes or so. Whether this is the down-clock phase or the time where it stops mining I don't know, but from the effective hashrate it is more the down-clock (2/180 idle cycle time won't make up for the 15% hashrate drop I have).

My attempts to circumvent throttling have been futile so far. Along with the suggestions made by other users in this thread I let it mine outside over night at < 14°C. No matter what, the 12h+ average comes down to ~715MH/s. I'm therefore pretty sure something went wrong when the heatpipe was mounted (the other 4 devices are always at ~815, no matter what). Look at the ztex thread: people are achieving significant speed improvements with different thermal grease / heatsinks combinations or the process how they are applied. Since no one tried that for BFL Singles so far, I'm not going to brick mine trying. I'll wait for EasyMiner and if that's not fixing it, mine goes back to BFL (it is at < 832MH/s - 10%).

The front LED flashes only for a few moments when the Single reduces its [clock speed?] hash rate, but not while it slowly increases its speed again.
Btw., my throttling issue seems to have been resolved by lowering the room temperature. I lowered it by turning off a GPU mining rig.

Got mine today (from someone else on the forum) it's with the single fan/new heat sink (whatever version that means)

I plugged it in to my desktop (linux) and 830Mh/s for the 41 seconds I ran it.
Thought this is nice - performing as expected ... time to take it down to the (underground basement) garage where my rig is
FYI here in Sydney Aus today it's 20°C where I am - my garage is cooler (it's autumn, winter in 1 month)

Took a while to work out how to get xubuntu 10.04 to recognise the BFL at all.
(luke-jr came up with the answer - anyone wondering: "sudo modprobe ftdi_sio vendor=0x0403 product=0x6014")

After a few minutes running ... throttling.
This is odd - coz the temp (reported from cgminer) was below 50°C - always.
Throttling down to crappy hash rates 680MH/s ... for an extended time.
On exit with that:
 Runtime: 0 hrs : 34 mins : 1 secs
 BFL0  47.3C         | (5s):708.0 (avg):696.9 Mh/s | A:275 R:4 HW:0 U:8.1/m

Yeah that sux badly.

So I brought it back upstairs to run it in it's own cgminer and find its ... slightly better ...
But WTF?
It's reporting it's temperature always above 50°C now even though it's getting a slightly better average MH/s
Current stats:
 Runtime ~70 minutes
 BFL 0:  52.7C         | 733.6/743.0Mh/s | A:655 R:6 HW:0 U: 9.40/m

I'd guess this is going to be some 'return it' and get a replacement .......
As for their EasyMiner program - yeah I'm gonna expect some details of the extra protocol from them to see if I can fix this thing myself.

I bought this for a few reasons:
1) cgminer (obvious - I wrote some of it)
2) I only had to pay BTC to the person I got it from
3) I got it in LESS than a week after I discussed buying it from them

I guess it's time to try email ... unless someone else can supply the extra protocol commands
(or has a copy of EasyMiner to watch what it sends to the BFL)

Edit: oh and the front led supposed to flash? Never seen it do it (except at power on for a short while)

Makes sense, you'll generally improve thermal performance by having the fans "push" airflow rather than pull, as the flow is much more turbulent, increasing the amount of heat leeched away from the surface due to the increase in boundary-layer vorticity.

I already tried dismantling the case of the throttling one along with what was suggested by the other users. Nothing did really help, i.e. the time between the start of mining and first throttling varies with the attempts, but once it starts it does it with same frequency, resulting in a long-term hashrate of 710-730MH/s.

The best I got so far was a result of pure monkey testing: I turned the upper fan and put it back into the housing. Instead of blowing out the heat-pipe's hot air to the top, it now sucks the fresh air from there and pushes it through the heat-pipe and the VRMs to the side exhausts. It's just a trial-and-error result and people familiar with thermal design might argue this is stupid, but it works for me.

I also have a unit that is less tolerant of higher than supported ambient temperatures.  The room is 75 instead of 72 and one of my singles throttles regularly while the other never does. Until I can try EasyMiner's tuning, I have been trying to improve airflow in hopes that I can reduce throttling as much as possible. 

To that end, last night I removed the U-shaped cover piece to the unit that was throttling (the piece that wraps around the sides and the front) to expose the heatsinks and fans.   With that piece removed, the device stopped throttling in the 75 degree ambient temperature.  Note, I do have a room fan pointed at the table these are sitting on and so my assumption is that with the case removed, that room fan is providing enough additional circulation to offset the increased ambient temperature.

So it's something you might want to try.  Note, to remove this easily, you only want to remove the 4 small screws on the sides (2 per side).  The "back" is the side with the USB and power connections.  There are 4 small screws there you want to leave alone.

Side note: I hope EasyMiner's speed adjustments will be persisted in nvram or something?  So, if it is a windows-only app, I can make the adjustment and then move the Single back to my linux rig?  If not, please make the protocol for adjusting the speed public so that the cgminer developers can add this feature directly.

Thats at least some helpful information.

To understand the SW side it would have been more interesting to know what exactly happens during throttling, i.e. does it just stop hashing but remains accessible (e.g. for temperature readout), or is it completely gone during that phase. Never mind, it will take me some time but I'll find out myself.

As for EasyMiner, I'd like to try the demo version you mentioned above to have it as reference, if possible.

Thanks.

Zefir,

I'm glad you like the product.  We're doing our best to keep up with customer request as well as our own internal development for future products.  This industry is moving fast.  

The most popular software package in use for mining with BitForce hardware is currently CGminer.  It's only fault is that it doesn't auto detect the units as they're plugged into the chain.  Ufasoft is pretty good, but it's lacking in features as compared to CG.  I understand mpbcm is also an excellent choice for BitForce owners.  It both auto detects and provides a golden suite of data.

Having said all this, I'm really not qualified to comment on the inner workings of any of the software miners.  The hardware itself has no ability to influence the behavior of another device on the chain, so if you're experiencing that now, I would have to assume it's something to do with whatever software you're using.  We use Easy Miner here in the shop to do our testing.  It's diagnosis & testing function runs known problems with known results without any outside network issues able to affect the performance evaluation.  It handles multiple units without any influence from a throttling unit.  Perhaps that's helpful to you.

Thanks for the feedback, BFL.

Glad to hear you expanded your customer service capacity - I'll maybe need it soon. As for the right email address, all mails I received from BFL where sent from sonny@bfl, including the shipment notification from last week. If that address is not valid any more, you still should assume that your customers just hit the reply button to contact you.

Then you are essentially saying that one needs AC to reliably operate the Singles. As stated above, the devices are hot spots and heat their surrounding area to a point where you need to actively cool the ambiance or add external fans to increase convection. Reality check: I'm operating them in April in the Swiss Alps in an passively cooled (aka open window) cellar room that is at 18°C when mining rig is off. If that's not 'cold' enough, where in the world can they operate during summer without AC?

Fact is, you nowhere wrote that the claimed performance is limited by ambient temperature. Why is that? Why do you let your customers lurk the forums here to collect relevant information? I mean, you still claim the housing is 88*88mm^2 at the product page, while people holding the Singles in their hands can measure they are 110*105mm^2   You really do not disclose trade secrets if you add all those pieces of information collected in this forum to the product page. Remember, Bitcoin is based on openness...


As for the EasyMiner, I guess it is Windows-only and therefore useless for me. But if you want to support the current matter, could you just check if adding a throttling unit to a set of non-throttling units reduces their average hashrate (as I described above)?

I fully understand the challenges with building such a device and repeat my above statement: your product is great, period. But your customers are part of an open society and you should have been prepared to provide an according information policy. I'm biased and surely not objective enough, but I hope it did not sound too harsh and you can take it as valuable input to improve further.


All the best, zefir

I'm sorry you've had trouble getting a response.  We've added staff to handle customer service and your email thread may have been lost in the transition.  Try a new request to office@butterfly... (not sonny@butterfly...)   and you'll get prompt responses.  (again, sorry for the difficulty during the last month or so...  we've been stretched thin).

With regards to what we mean by ambient temperature...  Room temperature or building set thermostat temperature isn't a very good guide as you point out.  We recommend placing a thermometer next to the unit in question and you'll know for sure.  If there's throttling at 72f, then I would be very surprised.  Each unit is tested prior to shipment at higher temperatures than that while operating at 832 mh/s.

Also note that although the temp spec is with the hardware running at a speed of 832 mh/s.  Tuning it down to 816 or 808 mh/s will have a significant effect on it's tolerance and allow you to run in higher ambient temperatures.  The net result is a higher effective hash rate than 832 with throttling (depending on temperature stress).  Likewise, slower speed increments down to 768 will allow you to run in almost any environment without throttling.

Our Easy Miner software will allow you to test & tune.  It's in beta...  and still buggy but it will accomplish this task for you.  We can probably get a demo version prepped in the next week to let you play with speed tuning.

On the chips in general and their variances...  please understand that when chips are fabricated, not all are the same.  These variances are a normal part of the process.  Industry practice has the units sorted and sold per speed grade.  In our case, we've simply packaged the end product with the lowest common denominator performance which is 832 mh/s (+ - 10%) at 72f.  

Regards,
BFL

BFL (through this post, BFL refers to the company, not to Sonny personally),

with due respect, while the Singles are lovely devices, your customer service sucks. Since the run for your products started, I contacted you 6 times with concrete technical inquiries and got zero responses (just ask BFL-Engineer, and FYI, that's why I did not order a (Mini) Rig). Therefore I preferred to get support from the community.

Plus it should be in BFL's best own interests when existing issues are discussed here openly and workarounds are made available publicly (or you add the related information at your product pages). Like Inspector said above, most of us would prefer fixing it by ourselves over waiting months for a RMA replacement.

That said, you need to clarify how you define ambient temperature. My setup is in a fairly large room in my basement with currently around 19°C room temperature. Naturally, as I approach the mining rig, local temperature gradually climbs and reaches ~23°C at half a meter distance. Given that the exhaust temperature right above the Singles is somewhere between 30 and 40°C, it's a physical imperative to have a local area with >22C° (or 72°F; any chance US is going to use SI-metrics soon? ).

I strongly believe that my operational environment is within specs, though the problematic device averaged down to 705MH/s after a continuous run for days. Again, I'm with Inspector arguing better to have it running at 500MH/s than waiting weeks for a replacement at 0MH/s. Therefore I'm going to first try the proposals the community posted, thanks to all.


While I am at it, I figured out a SW issue that could be quite relevant for all multi-Single setups driven by cgminer: while I removed the throttling device from the setup for further inspection, the average hashrate of the remaining 4 climbed up noticeably. To double check, I repeatedly run it long enough to exclude variation and this is what I get:
1) running all 5 devices the hashrate for all of them starts at 828 and after running a day the throttling settles at 705 all-time-average, while the properly working ones settle at 790
2) running the 4 proper ones alone, all start at 828 and after the day they are still at ~825

In other words, the throttling one is not just reducing its own hashing power but also those of the proper ones. In my 5-units setup the estimated loss is ~250MH/s.

This could be caused by the communication between PC and Single being frozen during the throttling. From the SW design view there should theoretically be no inter-dependencies, since every device is handled by its own threads. But in practice if the device throttles while communicating to the host and thereby stalls, the related thread will eat its scheduling quantum busy looping the serial port.

Luckily ckolivas is not only cgminer developer but also a Linux scheduler guru, so I'll sort this SW issue out in his thread. Meanwhile I will separate the throttling device from my setup and run it from a different host.

Tl;dr: if you have a multi-BFL Singles setup with one or more throttling units (front LED is blinking now and then) you should consider operating the throttling ones from a different host for a better overall hashrate.

Here's what I will do:
1. I'll move the "problem Single", which currently is in the middle of the room together with one other Single, to the "nest" of 6 singles, which happens to be quite close to the office door.
2. I'll measure the hallway temperature, which is quite low, judging from what I feel
3. I'll move the "problem Single" to the hallway for, say, half an hour and watch whether it throttles
4. If the hallway temperature is 72 degrees or below, as I think it is, and the "problem Single" throttles, I'll RMA it.
5. Otherwise, I'll just suck it up. It still mines, just not at 820 MH/s...