ursa
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April 22, 2012, 12:15:52 PM |
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aTg, You're so right! Keep the ideas for the people capable of understanding them...
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The grue lurks in the darkest places of the earth. Its favorite diet is adventurers, but its insatiable appetite is tempered by its fear of light. No grue has ever been seen by the light of day, and few have survived its fearsome jaws to tell the tale.
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gyverlb
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April 22, 2012, 01:48:25 PM |
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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...
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coretechs
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April 22, 2012, 07:45:18 PM |
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Will the new quad be available without heatsinks & fans at lower cost?
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BR0KK
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April 23, 2012, 09:13:23 PM |
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Just ordered one; hope it arrives here Sooooon
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Gomeler
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April 23, 2012, 09:28:11 PM |
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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...
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.
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BR0KK
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April 23, 2012, 09:34:56 PM |
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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
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gyverlb
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April 23, 2012, 10:38:21 PM |
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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).
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Gomeler
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April 23, 2012, 11:19:06 PM |
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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).
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ztex (OP)
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ZTEX FPGA Boards
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April 24, 2012, 09:39:47 AM |
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Will the new quad be available without heatsinks & fans at lower cost?
Yes. This would be 16 EUR cheaper.
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ztex (OP)
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ZTEX FPGA Boards
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April 24, 2012, 09:54:37 AM |
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antirack
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April 24, 2012, 11:04:36 AM Last edit: April 24, 2012, 11:23:02 AM by antirack |
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I have been running two test boards of the 1.15y (and three 1.15x) for a few days now (licensed production). 001-0: ztex_ufm1_15y1-0000004-01-1: f=228.00MHz, errorRate=0.00%, maxErrorRate=1.07%, hashRate=228.0MH/s, submitted 17 new nonces, luckFactor=0.96 001-0: ztex_ufm1_15y1-0000004-01-2: f=232.00MHz, errorRate=0.00%, maxErrorRate=0.50%, hashRate=232.0MH/s, submitted 13 new nonces, luckFactor=1.02 001-0: ztex_ufm1_15y1-0000004-01-3: f=232.00MHz, errorRate=0.54%, maxErrorRate=0.99%, hashRate=230.7MH/s, submitted 12 new nonces, luckFactor=0.96 001-0: ztex_ufm1_15y1-0000004-01-4: f=224.00MHz, errorRate=0.25%, maxErrorRate=0.97%, hashRate=223.4MH/s, submitted 18 new nonces, luckFactor=0.98 001-0: ztex_ufm1_15y1-0000004-02-1: f=224.00MHz, errorRate=0.00%, maxErrorRate=0.65%, hashRate=224.0MH/s, submitted 12 new nonces, luckFactor=1.00 001-0: ztex_ufm1_15y1-0000004-02-2: f=228.00MHz, errorRate=0.33%, maxErrorRate=1.38%, hashRate=227.2MH/s, submitted 10 new nonces, luckFactor=1.05 001-0: ztex_ufm1_15y1-0000004-02-3: f=232.00MHz, errorRate=0.69%, maxErrorRate=2.62%, hashRate=230.4MH/s, submitted 14 new nonces, luckFactor=1.00 001-0: ztex_ufm1_15y1-0000004-02-4: f=220.00MHz, errorRate=0.00%, maxErrorRate=0.00%, hashRate=220.0MH/s, submitted 7 new nonces, luckFactor=1.00 001-0: ztex_ufm1_15d4-04A3469722-1: f=216.00MHz, errorRate=0.00%, maxErrorRate=0.66%, hashRate=216.0MH/s, submitted 13 new nonces, luckFactor=0.97 001-0: ztex_ufm1_15d4-04A346CEC7-1: f=216.00MHz, errorRate=0.08%, maxErrorRate=1.19%, hashRate=215.8MH/s, submitted 11 new nonces, luckFactor=0.94 001-1: ztex_ufm1_15d4-04A32E00E9-1: f=212.00MHz, errorRate=0.00%, maxErrorRate=1.35%, hashRate=212.0MH/s, submitted 15 new nonces, luckFactor=1.00 001-0: poll loop time: 123ms (USB: 11ms network: 112ms) getwork time: 262ms submit time: 260ms 001-1: poll loop time: 14ms (USB: 0ms network: 14ms) getwork time: 391ms submit time: 337ms Total hash rate: 2459.6 MH/s Total submitted hash rate: 2421.3 MH/s --------
Total Device #01: 913 MH/s Total Device #02: 901 MH/s The last 3 units are 1.15x. Room temperature is 25C, I am using the stock heatsinks with fans. They are very stable and I have seen even more impressive hash rates (had them running on <20C AC for a while). Connected to a low cost Atom board with 2GB memory running Ubuntu, using 0% CPU load average 0.00. Currently all (incl. Atom) powered by a very inefficient 350W Mini ATX PSU. My kill-a-watt device shows 199 Watt at the wall. The Atom board alone is 27 Watt. It will be interesting to see what happens if I move to a better PSU and passive cooling without the 11 small fans. In the photo above I was experimenting with different heatsinks. While the ones on the right are easier to mount (the mounts are attached to the heatsink) they were too noisy and so I replaced them with the stock heatsinks after two days (can't take a new photo, logged in remotely via RD then on to VNC to the Ubuntu box).
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gyverlb
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April 24, 2012, 11:14:41 AM |
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2 questions : - If I understand correctly from the original post the price goes down with volume cross-customers. Is there a page with the current applicable price or recent orders by date so that we can know at which price we will be buying ?
- Which miners do support the 1.15y today and which others are working on its support ?
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nelisky
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April 24, 2012, 11:38:04 AM |
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Regarding miner support, I should have that on cgminer soon, but since I don't own any 1.15y I'll depend on external testing to assert it does, in fact, work.
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spiccioli
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nec sine labore
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April 24, 2012, 11:48:22 AM |
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antirack,
what about putting a single big fan over the four low-profile heatsinks?
spiccioli
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BR0KK
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April 24, 2012, 12:53:52 PM |
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What did u do to become a beta tester ? Would love to test to!
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antirack
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April 24, 2012, 01:16:33 PM |
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antirack,
what about putting a single big fan over the four low-profile heatsinks?
spiccioli
I am sure that would work, but i am going to put them in a case so I don't need any individual fans on the units. I'll just use (case) fans and establish air flow through the case, forcing the air through the heat sinks (similar to servers, channeling the air with styrofoam if I have to). What did u do to become a beta tester ? Would love to test to! I have paid Ztex for the license and made them in "my own" assembly line here in Hong Kong. The two boards you see are from the test production.
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BR0KK
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April 24, 2012, 01:19:14 PM |
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Ahhhh nice to know, so you are producing boards for Ztex
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antirack
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April 24, 2012, 01:22:44 PM |
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Ahhhh nice to know, so you are producing boards for Ztex No, just mine. And I can only do that because I have access to a manufacturing facility and components (and I am very motivated to build my own mining cluster).
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BR0KK
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April 24, 2012, 01:36:50 PM |
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Ah ok
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Glasswalker
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April 24, 2012, 02:04:49 PM |
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Antirack: The 10port USB hubs your using in your photo (the blue one). Have you had any problems with them at all from a reliability standpoint?
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