Butterfly Labs - Bitforce Single and Mini Rig Box

[rjk]

If you could choose full or partial coverage of the overhang...  certainly full would be an easy choice.  I'm just pointing out that the practical value of doing so in this case is nil.   This is the result of our thermal simulations in designing the heatsink.  The reason the few mm on the edge of the spreader are left uncovered is for package fitting. 

Not that again, please...

How about running your own real-world tests to see if full coverage makes a difference? I'd be interested to know whether it did.

[BTCurious]

That paste doesn't look much better than the stock that the single ships with. I would try something higher-grade like IC Diamond, Thermaltake TG-1, or Arctic MX-4 maybe.. I used TG-1 and it dropped my temps by a solid 3*C

It's Cooler Master HTK-002. I don't know much about different thermal pastes, but Cooler Master is generally a good brand.

[rkozola]

My single which showed 0 processors and was DOA was delivered back to Sonny at BFL today.  Hopefully I get notified soon that a replacement is on its way to me.


edit.  and it will be shipping tomorrow.

[kano]

So chips are not sanded, it's the heat spreader what we see when someone removes the heatsink...

spiccioli.

The heatspreader is an integral part of the chip packaging, they don't apply it themselves.

... and they should hopefully stop sanding them since we all now know that the chip is an EP3SL150
(just not sure if they are new or 2nd hand)

[BTCurious]

http://www.youtube.com/watch?v=Ce3UCyfmrXc

[rjk]

http://www.youtube.com/watch?v=Ce3UCyfmrXc

LOL

[JWU42]

Just unpacked the singles - 1 of 6 sounds like the heatsink is loose -- rattles horribly.

Also - 1 of the singles shows loaded with the 816 firmware?!?

Anyone else get a single that DIDN'T come from the factory with 832 firmware?

[BFL-Engineer]

Just unpacked the singles - 1 of 6 sounds like the heatsink is loose -- rattles horribly.

Also - 1 of the singles shows loaded with the 816 firmware?!?

Anyone else get a single that DIDN'T come from the factory with 832 firmware?

For trouble-shooting, you can refer to http://www.butterflylabs.com/faq/
to resolve your throttling issue. Also, for the firmware, you can use Easyminer
to change the version.


Regards,
BF Labs Inc.

[kano]

...

From a technical perspective, I beg to disagree.

There's a thermal resistance RT1 from the die to the heat spreader, and a thermal resistance RT2 from the heat spreader to the cooler. While RT1 cannot be changed, it is a good thing to minimize RT2. One way of minimizing RT2 is by removing the heat from the whole area of the heat spreader.

So ... that edge is OK (cool) to touch with your finger right?
Coz if it wasn't, none of this discussion that saying it doesn't matter would make any sense to me ...

[Inspector 2211]

...

From a technical perspective, I beg to disagree.

There's a thermal resistance RT1 from the die to the heat spreader, and a thermal resistance RT2 from the heat spreader to the cooler. While RT1 cannot be changed, it is a good thing to minimize RT2. One way of minimizing RT2 is by removing the heat from the whole area of the heat spreader.

So ... that edge is OK (cool) to touch with your finger right?
Coz if it wasn't, none of this discussion that saying it doesn't matter would make any sense to me ...

Exactly my point, Kano.
Of course, the ledge that is not covered by BFL's heat sink is NOT cool to the touch.

[nedbert9]

So chips are not sanded, it's the heat spreader what we see when someone removes the heatsink...

spiccioli.

The heatspreader is an integral part of the chip packaging, they don't apply it themselves.

... and they should hopefully stop sanding them since we all now know that the chip is an EP3SL150
(just not sure if they are new or 2nd hand)

Correct me if this isn't really a big deal, but aren't rough chip surfaces really bad for heat transfer?

I saw some articles about ppl buffing their GPU heatsinks to a shine prior to installing them.

[BTCurious]

So chips are not sanded, it's the heat spreader what we see when someone removes the heatsink...

spiccioli.

The heatspreader is an integral part of the chip packaging, they don't apply it themselves.

... and they should hopefully stop sanding them since we all now know that the chip is an EP3SL150
(just not sure if they are new or 2nd hand)

Correct me if this isn't really a big deal, but aren't rough chip surfaces really bad for heat transfer?

I saw some articles about ppl buffing their GPU heatsinks to a shine prior to installing them.

His point is that these surfaces are sanded, but quite roughly, ie, not polished to a shine. This is my Single for example:

[SgtSpike]

So chips are not sanded, it's the heat spreader what we see when someone removes the heatsink...

spiccioli.

The heatspreader is an integral part of the chip packaging, they don't apply it themselves.

... and they should hopefully stop sanding them since we all now know that the chip is an EP3SL150
(just not sure if they are new or 2nd hand)

Correct me if this isn't really a big deal, but aren't rough chip surfaces really bad for heat transfer?

I saw some articles about ppl buffing their GPU heatsinks to a shine prior to installing them.

Yes, but more important is that the surfaces are even.  In other words, you should be able to take a razorblade and put it across the chip in any direction, and not see any gaps where light can shine through.

I'm not sure that it would be feasible to lap the chips as they sit on the board though... so much could get in the way on all the edges, and you don't want to accidentally discharge static electricity to the board while you're rubbing it with sandpaper!  In other words, I wouldn't advise anyone to do it.  But, I would love to see someone try and see what the results are!

[Mobius]

Has anyone tried some of these: http://indigo-xtreme.com/

I use Cooljag's Thermal Compound (Shin-Etsu x23-7762) on all my GPU's it works far better than Artic or IC Diamond for the uneven surfaces.

Cost shouldn't be a big limiting factor with TIM, if you already paid $600 for the unit and $10/15 difference in better product is a wise insurance investment.

[steamboat]

Has anyone else noticed how the heatpipe cooler on the rev3 doesn't really cover the second FPGA? It is short by about 5cm. The center of the chip is covered but one whole side is left open.

I noticed this also. If this heatpipe is really custom made the job wasn't done good.

I'm thinking about putting a metal plate between the FPGA's and the heatpipe. This metal plate should cover the full area of both FPGA's and transfer it to the heatpipe. Maybe this could improve the cooling which is obviously mainly limited by the only parted covered FPGA.

Has someone already done this?

Adding any additional substance will only increase thermal resistance and makes cooling less efficient.
The aluminium plate which the heatsink sits on, is a by itself a heat-spreader directly attached to the die inside.


Regards,
BF Labs Inc.

I would agree here, don't add anything extra or your temps will just go up.

The heatsink itself could be better for sure, the aluminum part could be solid copper for start; and I noticed it is slightly short as well, however the copper pipes seem to touch the surface of the chip where the aluminum part cuts off, so that's something I suppose.

Again...  to clarify...   (trying to save unnecessary efforts among users), the chip itself is smaller than the aluminum heat spreader you see.  There is no purpose in trying to extend the heatsink out to the edge of the heat spreader because there is no heat being generated under the edge...  There is only air there.  See picture above for visual reference.

From a technical perspective, I beg to disagree.

There's a thermal resistance RT1 from the die to the heat spreader, and a thermal resistance RT2 from the heat spreader to the cooler. While RT1 cannot be changed, it is a good thing to minimize RT2. One way of minimizing RT2 is by removing the heat from the whole area of the heat spreader.

If you could choose full or partial coverage of the overhang...  certainly full would be an easy choice.  I'm just pointing out that the practical value of doing so in this case is nil.   This is the result of our thermal simulations in designing the heatsink.  The reason the few mm on the edge of the spreader are left uncovered is for package fitting. 

I understand the reasoning behind fitting the heatsink inside the case, but I must disagree with it not having a significant value. Mining is all about min/maxing. the heatsink could have quite easily extended the .25 inch (i'm guessing based on this picture) to gain the extra dissipation. The design of the enclosure for the single is absolutely terrible for dissipating heat, causing the fan to work harder to get less airflow. As far as the hack job you have done sanding the chip, here's an article from 1999 explaining what should be common sense.

 I like the singles, and I like what i've seen of the rig box, you guys have done a decent job at creating a product that fills a need in the market cheaply. That being said, your thermal solutions have been quite terrible/sloppy , and all the designs for the rig box are showing signs of the same backwards logic. I understand every startup company has growing pains, and i don't expect you to get everything right the first time, but please stop making excuses for poor designs and start fixing them.

[steamboat]

So chips are not sanded, it's the heat spreader what we see when someone removes the heatsink...

spiccioli.

The heatspreader is an integral part of the chip packaging, they don't apply it themselves.

... and they should hopefully stop sanding them since we all now know that the chip is an EP3SL150
(just not sure if they are new or 2nd hand)

Correct me if this isn't really a big deal, but aren't rough chip surfaces really bad for heat transfer?

I saw some articles about ppl buffing their GPU heatsinks to a shine prior to installing them.

Yes, but more important is that the surfaces are even.  In other words, you should be able to take a razorblade and put it across the chip in any direction, and not see any gaps where light can shine through.

I'm not sure that it would be feasible to lap the chips as they sit on the board though... so much could get in the way on all the edges, and you don't want to accidentally discharge static electricity to the board while you're rubbing it with sandpaper!  In other words, I wouldn't advise anyone to do it.  But, I would love to see someone try and see what the results are!

i would be more concerned with the metal dust you'd be blanketing the board in.

[heavyb]

has anyone upgraded to the 872 firmware? If so, how has the performance been?

[BFL]

Has anyone else noticed how the heatpipe cooler on the rev3 doesn't really cover the second FPGA? It is short by about 5cm. The center of the chip is covered but one whole side is left open.

I noticed this also. If this heatpipe is really custom made the job wasn't done good.

I'm thinking about putting a metal plate between the FPGA's and the heatpipe. This metal plate should cover the full area of both FPGA's and transfer it to the heatpipe. Maybe this could improve the cooling which is obviously mainly limited by the only parted covered FPGA.

Has someone already done this?

Adding any additional substance will only increase thermal resistance and makes cooling less efficient.
The aluminium plate which the heatsink sits on, is a by itself a heat-spreader directly attached to the die inside.


Regards,
BF Labs Inc.

I would agree here, don't add anything extra or your temps will just go up.

The heatsink itself could be better for sure, the aluminum part could be solid copper for start; and I noticed it is slightly short as well, however the copper pipes seem to touch the surface of the chip where the aluminum part cuts off, so that's something I suppose.

Again...  to clarify...   (trying to save unnecessary efforts among users), the chip itself is smaller than the aluminum heat spreader you see.  There is no purpose in trying to extend the heatsink out to the edge of the heat spreader because there is no heat being generated under the edge...  There is only air there.  See picture above for visual reference.

From a technical perspective, I beg to disagree.

There's a thermal resistance RT1 from the die to the heat spreader, and a thermal resistance RT2 from the heat spreader to the cooler. While RT1 cannot be changed, it is a good thing to minimize RT2. One way of minimizing RT2 is by removing the heat from the whole area of the heat spreader.

If you could choose full or partial coverage of the overhang...  certainly full would be an easy choice.  I'm just pointing out that the practical value of doing so in this case is nil.   This is the result of our thermal simulations in designing the heatsink.  The reason the few mm on the edge of the spreader are left uncovered is for package fitting.  

I understand the reasoning behind fitting the heatsink inside the case, but I must disagree with it not having a significant value. Mining is all about min/maxing. the heatsink could have quite easily extended the .25 inch (i'm guessing based on this picture) to gain the extra dissipation. The design of the enclosure for the single is absolutely terrible for dissipating heat, causing the fan to work harder to get less airflow. As far as the hack job you have done sanding the chip, here's an article from 1999 explaining what should be common sense.

 I like the singles, and I like what i've seen of the rig box, you guys have done a decent job at creating a product that fills a need in the market cheaply. That being said, your thermal solutions have been quite terrible/sloppy , and all the designs for the rig box are showing signs of the same backwards logic. I understand every startup company has growing pains, and i don't expect you to get everything right the first time, but please stop making excuses for poor designs and start fixing them.

I think it's important to point out once again that there is *NO* chip under the edge of the heat spreader.  The heat transfer capability from actual chip to heat sink via that area of heat spreader overhang is fantastically insignificant.  IE - it makes no practical difference to the thermal efficiency of the heatsink.  Suggesting otherwise, or promoting the idea that this is a cause of throttling isn't helpful to any user of the product.  I'm not pointing this out to win an argument.  I'm trying to save customers from confusion, misunderstanding and waste of effort.  Each of the chips have their own throttling point.  If you are working to improve the efficiency of any given unit, focusing on this area is akin to a snipe hunt or worse...  it could create heat problems such as the suggested metal plate insertion to try and extend coverage to this area. 

With regards to the 'sanding', extreme care was taken on the run of chips which had that treatment.  It was done with plastic abrasion and full vacuum draw.  90% of the chips shipped have no 'sanding' at all and are free of any marking.

[SgtSpike]

So chips are not sanded, it's the heat spreader what we see when someone removes the heatsink...

spiccioli.

The heatspreader is an integral part of the chip packaging, they don't apply it themselves.

... and they should hopefully stop sanding them since we all now know that the chip is an EP3SL150
(just not sure if they are new or 2nd hand)

Correct me if this isn't really a big deal, but aren't rough chip surfaces really bad for heat transfer?

I saw some articles about ppl buffing their GPU heatsinks to a shine prior to installing them.

Yes, but more important is that the surfaces are even.  In other words, you should be able to take a razorblade and put it across the chip in any direction, and not see any gaps where light can shine through.

I'm not sure that it would be feasible to lap the chips as they sit on the board though... so much could get in the way on all the edges, and you don't want to accidentally discharge static electricity to the board while you're rubbing it with sandpaper!  In other words, I wouldn't advise anyone to do it.  But, I would love to see someone try and see what the results are!

i would be more concerned with the metal dust you'd be blanketing the board in.

Yeah, that's a fair point as well.  Would definitely need to blow it off real good with a strong can of air or an air compressor.

has anyone upgraded to the 872 firmware? If so, how has the performance been?

Yes - 855 MH/s using the BitMinter miner.

[JWU42]

has anyone upgraded to the 872 firmware? If so, how has the performance been?

It worked on one of the 6 singles I received.  I haven't tried it on all 6 but know that 2 won't work (they throttle at 816 firmware).

816 yields a longer term avg of 798 - shows 811 most of the time.

872, as I recall, averages nearer 854 and shows 864 most of the time.