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Alright, so I have my antminer U1s (3 of them) overclocked to 2 GH/s each on a D-Link 7 powered hub connected to rpi running cgminer.

I plan to overclock to 4GH/s but , before I do that, I need to find a way to cool these. I am already using a Coolerguys 120mm USB fan, but the antminers are still getting too hot to touch even at 2GH if you touch them for a few seconds.

What should I do? Can these Antminer U1 (NOT S1) be water cooled, or should I buy more fans..?

I've bumped this thread 3-4 times now and deleted my own bump replies to avoid spam.

I need some help, please people!  ??? ??? ??? ??? ???

BEs are fine if they are to hot to touch for half a second, let alone a few seconds, and these should be too. You could likely hit 2.2GHs without any modifications. If you want to OC further, you will need to replace a pair of resistors, and add a heatsink to the back of the board, which would probably let you hit 3-3.4GHs depending on how much airflow, and how good the chips are.

I saw a guy that was submerging his BE in a small jar of mineral oil, and it was quite a bit cooler. You could look into that?

I guess you could remove the metal plate on the back, and use the bolts to bolt the U1 to a decent heat sink - like an old PC heat sink, or a big lump of aluminium our of a power amp or similar.  You'd need a heap of short USB extension cables, though.

I have ten of them in a Anker hub, all doing 2GH, with only a 140mm fan blowing across them.  

The Antminer U1 user manual provides no instruction or information on replacing any components.
On a picture it circles two resistors and leaves it at that!

I do have a list of bmsc freqs going up to 4 gh.

Also, is a heatsink necessary?

If you need any more information than that, then you shouldn't be doing the mods.


The metal backplate is a heat sink.  If you're overclocking more, then you need a bigger/better one.  2GH is about the limit of the supplied heat sink.

These dissipate heat from both the front and back. Zip-tying a small aluminum heatsink (chipset sinks anyone?) to the back with some thermal grease, or skipping the zip ties and using a thermal pad would probably allow you to hit 3-3.4GHs with a fan pointed at it. Thing is, you have a limit of 2.2GHs without replacing those resistors, which, if you need more information to figure it out than what the user guide supplies, you really shouldn't be trying to mod them, as you WILL break it if you try.

quite cool, maybe I will try on 1 unit U1 later

So, if you want 2.0 - 2.2 GH/s, just simply changing the clock settings is sufficient? That's good to know.

Yeah, mine run at 2.2GH not too bad at stock volts.  One out of the 10 is a big high in the HW errors, but still below 5%.

What's the frequency for 2.2GH/s? For some reason I thought 0981(2GH/s) was the limit without modifications...
Logically I would assume 1081, but these things aren't always logical!!

Mine are cool as a cucumber at 2, so I might as well push them a bit harder!

Cant you use thermal paste and then put the sink back on?

Make sure to check your pool performance if you are overclocking to 2.2 GH without replacing resistors.

One of my 6 Units will show the full 2.2 GH/s in CGMiner, but my pools will only show about 800 MH/s for that unit.

While viewing the local hash rate is useful, make sure to confirm the number with your pool.

In my experience (low sample size), some units are happy at 2.2, some at 2.0.

Good luck!

0a81  is 2.2 most of my sticks prefer 0981 only a few do well at 0a81

how about using the peltier effect: http://en.wikipedia.org/wiki/Thermoelectric_cooling

not sure if it will keep your rig moneymaking, but should be fun to do it

I don't know what fans the Antminer uses but there are some seriously fast fans out there.

You need to look for higher CFM to move more air faster over the cooling surfaces.

Also try and build a wind tunnel so it enters one side and exits the other.

I was recently supplied with Sunon 4.7W 4500RPM 75CFM on a Hex16B miner

http://www.alliedelec.com/search/productdetail.aspx?SKU=70226025

They are insane but there are even faster ones available from this supplier!

The U1 has no fan.  You're thinking about the S1.

Advice still stands though, larger surface area via heatsinks, and/or more air passing over the surface via a faster CFM rated fan.

Another option is run your stuff in a tank of mineral oil and pump that through a radiator with fans blowing through them.  ;D

Some seriously insane liquid cooling... http://bitell.sinaapp.com/show.php?tid=938

..but you can do it on a smaller scale at home in a fish tank with PC radiator/pump/fans.

Also you might like to try something like this...

Coolermaster ARC-U01 RAM Chip Cooler
http://www.ebay.com/itm/Coolermaster-ARC-U01-RAM-Chip-Cooler-/181206266073?pt=US_CPU_Fans_Heatsinks&hash=item2a30bc30d9
http://i.ebayimg.com/t/Coolermaster-ARC-U01-RAM-Chip-Cooler-/00/s/MTIwMFgxNjAw/z/DsgAAMXQ2kxSH-CP/$(KGrHqN,!okFI!-jvgj9BSH-CPc6uw~~60_57.JPG

Why would someone emerge it into oil, Why not use antifreeze? :D

Antifreeze is mostly water, so is electrically conductive.  Oil is not electrically conductive.

DERP.

I've also heard of liquid nitrogen cooling.

So could i have my USB HuB turned upside down over a tub of cooking oil, and have say, half the miner submerged, it would work as a cooler

Also, on the OC guide on the PDF Guide says the frequency hex is 5381, does that mean it would go to 4ghs, or is there soldering involved to get that done?

http://www.overclock3d.net/reviews/cases_cooling/scythe_ultra_kaze_120mm_fans/1

You can get one of these for like $10 shipped.  Friggin powerful fan.

I'd recommend adding a heat sink, although it is a bit of a fuss it probably works best.

 DO NOT USE COOKING OIL!  Some vegetable based oils have contaminants and acids that can harm your circuit boards. Not to mention that vegetable oil polymerizes when in contact with oxygen and heat causing a helluva mess.   Oil cooling is inefficient but if you must, obtain the purest Mineral oil you can or oil that is designed for electrical cooling

Immersion cooling is an interesting option, but doing it right is a tad pricy.  Novec 7000 is about $300 a gallon.  Mineral Oil is much more affordable, but is pretty messy.  You might be better off attaching a larger heatsink to the devices, or maybe a very large heatsink to all devices at once.

Immersion cooling is expensive and messy. Just install a heatsink!

Im going to buy liquid nitrogen. Its colder, and when my GPU or CPU heats up, I'll just pour in some more.

That stuff is expensive and dangerous. You can easily freeze you hand, and if not, break your rig.

Some guy demonstrated it on youtube. Its easy.

I never said it was difficult. If you leave your hand in the stuff for more than 3 seconds, you're a goner. And it could potentially freeze your rig and render it unusuable, unless you have a safe system of pouring the stuff in.

Im pretty sure its safe I am looking for the video right now. :)

Well you can try it, the stuff isn't cheap. Good Luck.

And once you used it up you will have to buy more.

Could I just use thermal paste and attach another heat-sink directly to the back of the current metal heat-sink directly. Could I in essence attach a long ie 15cm piece of metal to increase the surface area to cool down and still use a fan.

If so, what metal would i use.

I currently use a Ghetto Wind Tunnel made with a USB Desk fan and a Coke bottle with the top and bottom cut off.

http://i215.photobucket.com/albums/cc210/acheekymonkeyuk/Airsoft/miner_zpse8a0d143.jpg (http://s215.photobucket.com/user/acheekymonkeyuk/media/Airsoft/miner_zpse8a0d143.jpg.html)

Could I ramp this up and make a larger wind tunnel with 30x30cm bits of metal attached to the back of the miner

I think it's okay to do so, i don't see any problem with that.

What metal would be best to attach directly to the current heatsink in 20x20cm form and would help dissipate thebest

If you are willing to spend a lot of money, then attack a strip of silver or gold, they actually conduct heat the best.
If not, use a piece of copper or aluminium. Be careful though, silver and gold are also very electrically conductive.

What that guy was saying about attaching metal to the current heatsink,

would it just be a case of getting a 10x10cm piece of aluminum and thermal paste it directly to the current heatsink increasing the surface area for a fan to cool

I have two Artic Breeze USB Fans on my 10 Antminer cluster (4 in your D-Link USB hub) with no heating problems.  I took a infrared temperature gun to them and never got over 100F.  Also if you plan on overclocking past 2GB you will have to do some hardware modifications
 
http://www.amazon.com/gp/product/B003XN24GY/ref=oh_details_o03_s00_i02?ie=UTF8&psc=1

I've only been able to get 2GH/s without replacing resistors

I buy antminer u1 for fun and to see what can be done with it.First of all I made some monitor hardware to see what is happening on u1 and if temp is too high to automatically stop u1 and result is not so bad
overclock antminer u1 to 3 ghz
in txt file you can see monitoring 2 times in second
first is temp
second is current voltage
third i minimum voltage
and if some of values are off chart hardware is sending Q to antminer
Now is 3.9k resistor on antminer and oversized cooling from old cpu with fan and temp sensor in cooler

http://i766.photobucket.com/albums/xx306/bicoinr11/overcolockantmineru13ghz_zps95d3bef4.png (http://s766.photobucket.com/user/bicoinr11/media/overcolockantmineru13ghz_zps95d3bef4.png.html)