Topic: Monarch butterfly prototype (Read 7436 times)

Why are people still talk about bfl vaporware......
When they have anything hashing al others have double or more hashrates.....

BFL does not deliver. There are still busy with backlog and dont even have the money to refund.
They are stealing at the moment, there is enough proof.

Butterfly Labs is officialy a criminal organisation at the moment.

Just look twice at what you are buying guys.

Looks like the ends are made to snap off. I suppose that's not uncommon in the electronics industry when manufacturing PCB's.

+1

What chip?

should be a heater

RUBBISH! bfl please find a tall building and jump off...do the whole scene a favour

If you set aside the classic screwup on 65nm ASIC power consumption BFL did, the rest of their work shows they have some pretty competent electronic engineers even their firmware API is more elaborate than the competition.

I would disagree. Of course we don't know how the die is internally attached or even if it's a single monolithic die, but the chances are that the silicon interface to the base of the heatsink will be much, much better than with the Singles. Keep in mind that we're talking similar power levels here, my Single pulls 300W from the wall.

http://www.anandtech.com/show/6830/cpu-air-cooler-roundup-six-coolers-from-noctua-silverstone-and-cooler-master/4
Look at some good air or water coolers, and the whole die->heatspreader->paste->heatsink->ambient thermal path might have an effective impedance in the range of 0.25C/W to 0.5C/W.

Compare that to the even the exceedingly good and expensive thermal pads BFL uses.
http://www.fujipoly.com/usa/products/sarcon-thermal-management-components/thermal-gap-filler-pads/high-performance-gap-filler/xr-m.html (they use the 50X-Hm).
0.06Cin^2/W at a very high pressure of 72psi. Since the BFL die is 0.1in^2, that gives an effective thermal impedance of 0.6C/W just across the thermal pad, in the best case. In the case that one die is lower (or worse one is noticeably higher) those numbers could be much worse.

TL-DR, the thermal impedance of just BFL's expensive ($11/each if you cut 24 out of a full sheet) thermal pads is higher than the entire die to ambient impedance of a decent CPU cooler system.

Well the heat pipes are 8mm diameter each.  So that puts the minimum width more like <32mm. 

I took the KNC board photo measured the pixels across to get the resolution (pixels per mm).  Then measured the pixels between the two mounting holes.  Board has 6 mounting holes 4 inner which I believe are unused and two outer which are used for the heatsink.   That gave me the distance between the two mounting holes.  Then using the heatsink photo did the same thing to estimate the contact surface.  I did this a month ago for my own research but I may have made a mistake.

cooling those single's is positively childsplay compared to that Monarch. The fact they managed to botch that is telling.

Actually a 7990 will draw ~350W DC running furmark at stock clocks, or 100W more with overclocking. It definitely still won't be easy, but it's not like it's impossible. GPU makers are constrained by useability issues, they can push so far but people eventually put 7990s in cases that can have pretty poor airflow. The also need to at least pretend to care about acoustics. BFL doesn't have that problem, and a lot of cooling issues can be cured by sacrificing your hearing later in life to install a ridiculous amount of airflow.

I think they'll have less trouble cooling these devices than the Singles. The biggest problem with the Singles was the overdriven power supply running inefficiently and being poorly cooled prior to using all those little press on heatsinks everywhere, as well as being forced to use a gapfiller pad rather than paste due to levelness and coplanarity concerns. Remove the massive thermal impedance of the pad, and not only will your core temperatures drop, but you dump much less heat into the PCB and everything else stays cooler.

According to the drawings on arctic's site:
http://www.arctic.ac/en/p/cooling/cpu/473/freezer-a30.html
(click on compatibility, then scroll down)
it looks like the contact base front to back is no deeper than ~21mm, maybe 25mm if you include the aluminium bracket which Im not sure is supposed to make contact; thats considerably less than the 41mm of the KnC heatspeader. What picture are you looking at?


I think we are largely in agreement there.

They are stock and the base appears (eyeballing the board and heatsink photos larger than the package size.  Not sure if that is intentional design choice on Artic's part or if KNC just lucked out that Artic's sinks are larger than average.  Due to the direct heat pipe design there likely are some limits on how "short" the base of the pipes can be made.


That wasn't my claim either.  Smaller chip, higher power consumption, constrained device size combined create a significant thermal "challenge".  Not impossible but BFL has had difficulty properly cooling devices with much lower power densities and much more "open" form factors.

BFL is no AMD and even AMD had issues (and 7 month delay) cooling the 7990 and the 7990 still uses less power than BFL design is simulated to use.  If BFL is even over moderately it could go from insanely difficult to (economically) impossible.

They don't need to be mounted to a motherboard.  They can be freestanding or placed in other containers.  They will have USB connectors too.

My point is that BFL isnt going to struggle with hotspots on that chip and that its a smaller chip than KnC isnt their problem. Putting a 1000mm² heatspreader on a 300 mm² die (or set of dies) isnt going to work miraculously better than a 300mm³ heatspreader with a similar sized cooler. In fact, most overclockers will tell you you get better results by removing the CPU heatspreader and putting the cooler directly on the much smaller die (which is the case with most GPU's). The more important reason for that heatspreader is not miraculous heat conductivity, but making it less likely that you crack the chip or misalign the cooler..

Anyway, removing the 350+W of heat in a dual slot GPU sized package will be a stiff challenge, no question about that. Putting more than 2 in a case probably damn near impossible.  But I dont think it would be considerably easier with a monster size chip like KnC. In fact, and slightly OT,  Im looking forward to seeing some close ups of their cooling solution, AFAIk those  intel and amd coolers from Artic dont have a base surface area large enough to cover their entire heatspreader. Did they order a custom batch; or is part of their heatspreader not covered?

True I was simplifying to avoid turning it into a page long post.  However heat spreaders are larger than the die for a reason.  The thermal conductivity between silicon and the IHS is generally higher than the IHS and heatsink (or waterblock or air).  That is one reason the IHS is generally larger than the die.  If one the die size and die heat flux mattered there would be no reason (well no thermal reason) to use a larger IHS then the die.  


That is a good point on the "even" heat flux however GPU unlike CPU tend to be mostly core engine and thus are more like mining ASICs in that respect.  One ASIC vendor (HF) uses 4 9mm x 9mm dies with 5mm space between them in a single package to lower the heat flux.


Well no.   Thermal density does matter, it may not be a problem but it does matter.  A Bitfury rig uses ~400W yet needs no heat sink.   200 USB miners use ~400W yet don't even need a fan.   If you have a large lawn it probably has a thermal output (from IR exposure to the sun) of a couple KW (but at a very low heat flux) yet I doubt you run out there on a hot day and crank up a serious cooler to keep the lawn from bursting into flames.

All things being the same the higher the heat flux the more complex the cooling to remove the same amount of energy (watts) from a smaller space.  Baring some exotic tech that means larger heat sinks, more efficient (heat pipes) heat sinks, and more airflow.   With the constraint of a dual slot cooler that puts some boundaries on what is possible in the airflow and size parameters. 

Well, that is most strange part. It is not a prototype, it is just a PCB without the main processor. So how BFL managed to get this certifications without a finished prototype? This is really amazing. Look like everything goes backward in BFL business.

Instead to them...

Design -> Main processor ->  PCB -> Quality Test -> Announcement -> Sales

They go by...

Sales -> Announcement -> Quality Test -> PCB -> Main processor -> Design

Sooo....you are quoting about things you don't understand...oookayy...NEXT !