Will the new quad be available without heatsinks & fans at lower cost?
Yes. This would be 16 EUR cheaper.
Topic: ZTEX USB-FPGA Modules 1.15x and 1.15y: 215 and 860 MH/s FPGA Boards - page 25. (Read 182443 times)
April 24, 2012, 04:39:47 AM
Yes. This would be 16 EUR cheaper.
April 23, 2012, 06:19:06 PM
The compressor can run with 100% duty cycles. Refrigerators are typically not equipped with adequate condensers to reject the heat that is removed from the cold chamber and from the compressor inefficiencies. Swap an appropriate condenser and you'll be good to go.
My guess was indeed that the compressor was overheating.But I'm not sure that the compressor itself is meant to be cooled down by the condenser: the condenser is after the compressor in the cycle, so the compressor's input (warm vapor) should always have roughly the same temperature range (unless the whole fridge is overheating and mine wasn't). My guess is that (at least in my case) compressors have sufficient thermal inertia to not overheat during their common working periods (I'd guess 5 minutes at most) and then they are cooled by natural convection during their sleeping periods. I guess that if they have to work continuously, the natural convection isn't sufficient and they begin to overheat (lubricant is slowly cooked, the motor mechanism eventually becomes stuck).
You are partially correct. On mini-fridges the condenser coils are embedded in the walls of the unit close to the exterior. The mass of the walls are used to dump heat and that is radiated away over time. Some full-sized refrigerators use this same principle and others use a dedicated condenser with a fan. These are still sized for small loads as fridges normally don't have things inside of them that generate heat(except when your cat hops in the fridge).
I had a twin rotary cascade that ran for 8-12 hours at a time cooling a Xeon w3570 down to -110C. I built it for continuous runtime and it was able to reject all its heat through the 1st stage condenser and 2nd stage desuperheater. If you build them correctly, refrigeration systems will run until their compressors wear out(which can take a long time).
April 23, 2012, 05:38:21 PM
The compressor can run with 100% duty cycles. Refrigerators are typically not equipped with adequate condensers to reject the heat that is removed from the cold chamber and from the compressor inefficiencies. Swap an appropriate condenser and you'll be good to go.
My guess was indeed that the compressor was overheating.But I'm not sure that the compressor itself is meant to be cooled down by the condenser: the condenser is after the compressor in the cycle, so the compressor's input (warm vapor) should always have roughly the same temperature range (unless the whole fridge is overheating and mine wasn't). My guess is that (at least in my case) compressors have sufficient thermal inertia to not overheat during their common working periods (I'd guess 5 minutes at most) and then they are cooled by natural convection during their sleeping periods. I guess that if they have to work continuously, the natural convection isn't sufficient and they begin to overheat (lubricant is slowly cooked, the motor mechanism eventually becomes stuck).
April 23, 2012, 04:34:56 PM
Like phase change Cooling for PCs or Waterchiller. They are basically made out of refrigerator parts and Capable running 24/7.
But i won't put a 380€ Card near my Food. .... Im to (tollpatschig) and would probably drop something on it
But i won't put a 380€ Card near my Food. .... Im to (tollpatschig) and would probably drop something on it
April 23, 2012, 04:28:11 PM
Condensation may not be a problem. I wouldn't be sure until a test is done (20 minutes isn't enough) because air is warmed locally by the board and could eventually reach a cold surface just above the board were condensation would slowly build up if it hasn't time to cool down before. Seems unlikely to happen but I'll check such a setup regularly and wouldn't change what I place above the boards in the fridge without additional checks...
But that's the least of your problems. The compressor of a refrigerator isn't designed to work continuously and will break if it is forced to do so. I learned this painfully when the switch which should have cut the light in the refrigerator stopped working. After several weeks/months (I'm not sure when the switch failed exactly), the refrigerator was dead.
The light bulb in the refrigerator was only ~20W...
But that's the least of your problems. The compressor of a refrigerator isn't designed to work continuously and will break if it is forced to do so. I learned this painfully when the switch which should have cut the light in the refrigerator stopped working. After several weeks/months (I'm not sure when the switch failed exactly), the refrigerator was dead.
The light bulb in the refrigerator was only ~20W...
The compressor can run with 100% duty cycles. Refrigerators are typically not equipped with adequate condensers to reject the heat that is removed from the cold chamber and from the compressor inefficiencies. Swap an appropriate condenser and you'll be good to go.
April 23, 2012, 04:13:23 PM
Just ordered one; hope it arrives here Sooooon
April 22, 2012, 02:45:18 PM
Will the new quad be available without heatsinks & fans at lower cost?
April 22, 2012, 08:48:25 AM
Condensation may not be a problem. I wouldn't be sure until a test is done (20 minutes isn't enough) because air is warmed locally by the board and could eventually reach a cold surface just above the board were condensation would slowly build up if it hasn't time to cool down before. Seems unlikely to happen but I'll check such a setup regularly and wouldn't change what I place above the boards in the fridge without additional checks...
But that's the least of your problems. The compressor of a refrigerator isn't designed to work continuously and will break if it is forced to do so. I learned this painfully when the switch which should have cut the light in the refrigerator stopped working. After several weeks/months (I'm not sure when the switch failed exactly), the refrigerator was dead.
The light bulb in the refrigerator was only ~20W...
But that's the least of your problems. The compressor of a refrigerator isn't designed to work continuously and will break if it is forced to do so. I learned this painfully when the switch which should have cut the light in the refrigerator stopped working. After several weeks/months (I'm not sure when the switch failed exactly), the refrigerator was dead.
The light bulb in the refrigerator was only ~20W...
April 22, 2012, 07:15:52 AM
aTg,
You're so right!
Keep the ideas for the people capable of understanding them...
You're so right!
Keep the ideas for the people capable of understanding them...
April 22, 2012, 07:11:19 AM
Chill out 
I had to laugh when I read about the test. I like to hear what others do to improve performance.
I had to laugh when I read about the test. I like to hear what others do to improve performance. 
April 22, 2012, 05:29:51 AM
My God how many stupid things you read in this forum, the board just spent 20 minutes in the fridge for a test. Neither the food has been contaminated, nor was there any kind of condensation, because as someone said condensation can not be created on a hot surface.
It was just a test by someone on the forum if it seemed a good idea to put your FPGAs in a gas cooling system is very cheap as a refrigerator.
But from now on I will keep these tests for myself so I will not have to put up with absurd criticism.
It was just a test by someone on the forum if it seemed a good idea to put your FPGAs in a gas cooling system is very cheap as a refrigerator.
But from now on I will keep these tests for myself so I will not have to put up with absurd criticism.
April 21, 2012, 03:59:28 PM
Regardless of opinion on practical application of thermal dynamics, all the thinking available will not make it any smarter to place expensive electronics into a refrigerator and I would be rather certain in that doing that would instantly void any kind of warranty request for when, not if, the board stops working from whatever the next hair brained idea comes along. Seeing that picture was like seeing someone kick a puppy. That poor FPGA needs a good home. Please, stop the abuse.
Actually I don't see anything dangerous here. Condensation could possibly bite you when removing it from the fridge, but only if it wasn't mining immediately before it gets removed from it. Condensation isn't likely to happen at all here.
I consider it a valid approach at evaluating the thermal behavior of that board.
April 21, 2012, 12:11:42 PM
U can get them in every good hardware supplier. I got mine from a local store in Freiburg.
Awwww I want to have 15 more of these units. I only could afford 5 ATM
Awwww I want to have 15 more of these units. I only could afford 5 ATM
April 21, 2012, 10:57:29 AM
20x 1.15x running very stable now. Thanks for that great product.
Here is my setup if anyone is interested:
http://i.imgur.com/ISSYe.jpg
Here is my setup if anyone is interested:
http://i.imgur.com/ISSYe.jpg
This is so beautiful
. Can you tell me where you got this spacer thingies you used to stack the singles? April 21, 2012, 03:45:47 AM
if you collect enough condensation points, you get to bonus round.
Won't happen.
Condensation happens when warm air meets a cold surface.
But in the fridge, air is cold and the FPGA is warm.
No.
Think...
April 21, 2012, 03:30:57 AM
Interested in the EU Group, but i cant understand german , so i 'd rather an english group ( in this forum will be great....so no need of new registering issues)
If you write Chefnet in English he will understand you. So where is the problem? He's already at a good amount of units and this makes the price even better. If you need some post translated and google translator or other tools are not good enough, point e.g. me to it and I gonna tell you what it says. April 21, 2012, 12:48:49 AM
if you collect enough condensation points, you get to bonus round.
Won't happen.
Condensation happens when warm air meets a cold surface.
But in the fridge, air is cold and the FPGA is warm.
April 20, 2012, 04:52:06 PM
20x 1.15x running very stable now. Thanks for that great product.
Here is my setup if anyone is interested:
http://i.imgur.com/ISSYe.jpg
Here is my setup if anyone is interested:
http://i.imgur.com/ISSYe.jpg
Those USB cables can be a pain when you have a large cluster. Those standoffs are a nice touch. How high are they? Do you notice any speed/heat issues with the bottom boards?
April 20, 2012, 03:41:57 PM
Interested in the EU Group, but i cant understand german , so i 'd rather an english group ( in this forum will be great....so no need of new registering issues)
.
.
April 20, 2012, 02:36:09 PM
It's about as clean as you can get without making your own custom USB cables.
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