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1501  Other / CPU/GPU Bitcoin mining hardware / Re: Buy or sell 5970?! on: January 24, 2012, 02:59:03 PM
I dont think resale value of the 7970s will be much better. It is of course now, but expect those prices to implode once nvidia's Kepler hits the market in a few months. Better hang on to those 5970s IMO, far better MH/$ now and comparable (if not superior) MH/W depending how much you can undervolt either card.
1502  Bitcoin / Pools / Re: [90 GH/s PPLNS] BitMinter.com *** Merged Mining! *** on: January 24, 2012, 02:39:44 PM
Just curious, what was the problem?
1503  Bitcoin / Pools / Re: [18 GH][0% Fee] A1BITCOINPOOL.COM 13 BTC BONUS PROPORTIONAL POOL on: January 24, 2012, 10:43:56 AM
Pool is down.
1504  Bitcoin / Pools / Re: [90 GH/s PPLNS] BitMinter.com *** Merged Mining! *** on: January 24, 2012, 10:41:24 AM
ozcoin is down too. Could it be a DDoS attack? most other big pools appear to be working though.
1505  Bitcoin / Pools / Re: [90 GH/s PPLNS] BitMinter.com *** Merged Mining! *** on: January 24, 2012, 08:51:01 AM
While the website is down, the backend still seems to work. Im not seeing any real problems?
1506  Economy / Goods / Re: [WTS]New Replacement fans ATI Video Card 4350 4870 4890 5450 5650 5850 5870 5970 on: January 24, 2012, 08:18:03 AM
For the most part, all these cards do indeed use the same fan (although Ive seen slight variations in amperage/wattage). The lowest end cards usually have a different non ref cooler, 5450s even tend to be passive, but for the cards that matter, these fans can be interchanged - for reference coolers.
1507  Other / CPU/GPU Bitcoin mining hardware / Re: Does anyone else have stability issues with linuxcoin on: January 24, 2012, 07:52:43 AM
Sounds like you have too many potential sources of problems. If I were you, Id start by plugging in a single card, with no extender cable and see what happens. If that magically solves all problems, slowly build form there, by adding the cables and extra cards and see when the problem occurs.
1508  Bitcoin / Bitcoin Technical Support / Re: Ubuntu with multiple 6970s not working - need serious help on: January 24, 2012, 07:42:13 AM
Your dmesg gives a good hint:

[    3.509706] vgaarb: this pci device is not a vga device
[    3.509714] vgaarb: this pci device is not a vga device
[    3.509721] vgaarb: this pci device is not a vga device
[    3.509727] vgaarb: this pci device is not a vga device
[    3.509733] vgaarb: this pci device is not a vga device
[    3.509739] vgaarb: this pci device is not a vga device
[    3.509745] vgaarb: this pci device is not a vga device
[    3.509751] vgaarb: this pci device is not a vga device

etc

If I were to guess, Id say you are using extender cables and at least one of them (to which the monitor is connected) is no good.
1509  Bitcoin / Mining / Re: Google Chrome Native Client - Full speed GPU Mining in a browser??? on: January 24, 2012, 07:23:06 AM
It downloads the .jnlp file when I try to go to Bitminter, and I can't seem to get Chrome to recognize that it can run that file because it does have Java. I can open a shell script on it though, but when I try to run it there, it throws a fit about basename or something. Any ideas?

Its a chrome issue. Look here:
http://www.petenetlive.com/KB/Article/0000354.htm
1510  Bitcoin / Mining / Re: Google Chrome Native Client - Full speed GPU Mining in a browser??? on: January 23, 2012, 10:01:46 PM
See https://bitminter.com/ for the answer...

bitminter uses Java. For mining, thats fine, all the performance sensitive code is opencl anyway, so wether the code is compiled C or anything else doesnt really matter; but its not native client like asked above.  It is however a fine miner that runs from a browser.
1511  Economy / Goods / Re: [WTS] Miner Parts (VGA, PSU, CPU, Extenders...) on: January 23, 2012, 09:13:42 PM
Id be interested in one 5870 and/or the 850W PSU, though that might get more expensive for shipping I imagine.
1512  Other / Beginners & Help / Re: Submersing a rig on: January 23, 2012, 08:07:43 PM
So you are suggesting I replace my precious Koi with these hellish creatures:



No thanks. Its so ugly I wouldnt even want to eat it Smiley.

If I were in it for the money, I even think growing Koi is the better investment. Though I would need warmer water... (or indoor winter tanks).
1513  Other / CPU/GPU Bitcoin mining hardware / Re: Does anyone else have stability issues with linuxcoin on: January 23, 2012, 07:50:54 PM
Will putty work if the windows computer I use is a laptop on wireless lan and the miners are wired?

Sure, no problem, as long as all the machines are on the same subnet (if you dont know what that is, then they are)
1514  Other / Beginners & Help / Re: Submersing a rig on: January 23, 2012, 07:38:47 PM
That is a baller pond. Start the aquaculture op!

Not sure what you mean. If you think there is not enough plants in the water, keep in mind thats early spring before most of the plants and lillies surface, and right after a thorough cleanup. in the summer you can almost walk across the pond without getting your feet wet Smiley.
1515  Other / Beginners & Help / Re: Submersing a rig on: January 23, 2012, 07:32:15 PM
Wouldn't an fish tank filter :
do just as well if not better than a radiator at cooling down the oil.

Definately not.  Its just a waterfall, all that matter is the surface area you produce, and that isnt much. Moreover, insummer inside the shed it already gets to 35+C without help from mining rigs, and I were to dump all the heat in there, it would get a lot hotter. And then you only have (hot) air to cool the oil, thats not nearly as efficient as cool water.
1516  Other / Beginners & Help / Re: Submersing a rig on: January 23, 2012, 07:26:50 PM
Sounds good.  Also if you wanted an added layer of security you could rig a temperature switch to the power for the rigs.  If temp in pond got above say 40C it would kill power to rigs.

Above 40C? Heh. Maybe I need a picture here to help you visualize 50K liter. Here is half the pond half drained for maintenance this spring:






A few gpus arent going to cause that to overheat Smiley.

Im much more worried about leaking. Ill probably add a floater switch that shuts everything down if the oil level drops. And probably an electric valve as well.
1517  Other / Beginners & Help / Re: Submersing a rig on: January 23, 2012, 07:07:06 PM
I guess one could get a ballpark figure by measuring the pond temp in summer at dawn and noon.  The rise in temp ~= thermal energy from sun.  Figure out solar insolation, and number of hours and you could turn that into wattage.  i.e. pond got x watts from the sun and the pond temp rose y.  That might give p4man at least the magnitude we are looking out.    With only a 5C rise in temp can the pond dissipate 100W, 1000W, 10,000W, etc?

Im not worried about that in the least. Temperature difference between bottom (where I pump most of the water) and top of the  pond can be 5-10C difference just from the sun. Between morning and afternoon you can add another 5+C to that when my filters are running. Fish dont mind. They will just swim where they feel most confortable, and if anything, Koi like warmer water than what I can offer them. They thrive when the water is ~30-35C, Ill never get there, except for some weeks per year at the top of the pond...

Once best avoids sudden temperature shocks, like from a hot bassin to a cool pond without some acclimatisation time, but intra day variance is not an issue. They are river carp, its not like you will not find huge temperature differences in a fast flowing shallow river.
1518  Other / Beginners & Help / Re: Submersing a rig on: January 23, 2012, 06:50:37 PM
2000w will more than likely impact 10,000 gallons, though it wholly depends a lot on surface area.

I dont believe so. the pond is not that deep. Its bowl shaped, no deeper than 1m60. Half the pond (by surface) is less than waist deep.   Surface area is 60m2. Then there is the fact I have a DIY "trickle tower"/ proteine skimmer thats designed to  expose the water to air and *lots* of aeration in general (heavy duty air pump in the filters and in the pond).  When I turn on all my pumps on a cold autumn day, I can easily decrease the water temperature by several degrees in a single day, 2000W isnt going to offset that.  Im not sure 20Kw would.

Anyway, heating the pond is not the objective. Heating the water in the filters would be quite a useful by-product, particularly in spring, although Im not expecting much difference even there. Too much flow. One can do the math, the filter barrels excluding filter material are probably around 200L and I believe are turned around every 4 minutes. At 2000W that is  ~ +0.5C. Better than nothing, but not impressive.
1519  Other / Beginners & Help / Re: Submersing a rig on: January 23, 2012, 06:03:47 PM
Why not just use a traditional water cooling rig w/ a heat exchanger?

Price mostly. And convenience. Equipping 6 or 10 cards with full covers for watercooling is expensive, and it could be hard to find covers for all my cards. Remember I run rat rigs thrown together with leftover parts and then I plug in whatever 58x0 card I can find cheaply. I have like no 2 identical cards, and thats only gonna get worse Smiley.

Quote
As far as what temps are GPUs.  In watercooling (and I would imagine oil cooling too) water is such a good heat conductor that everything in the loop is within 1 or 2 degrees of everything else.  So if the oil reaches equilibrium around 50C then the GPU would be 50C.

Some more googling suggested that too. Well, up to 5-7C delta. This is getting more and more exciting Smiley.

Quote
If the radiator will be submerged in water you likely will get better heat transfer with a heat exchanger.  Radiators are designed assuming they will be used to force air through fins to acheive heat transfer. 

Heat exchangers require I pump water through them. Thats probably not a good idea, considering its pond water; its gonna clog sooner or later, even if I were to pump "clean" water from the end of the filter (and Id rather heat the beginning of the cycle to help the aerobic process).  My filters are connected with 130 mm pipes, that doesnt clog so easily Smiley. Moreover, it requires 2 pumps, one for the oil, one for the water. Thats 2 points of failure.

 Then there is also... price. A decent sized heat exchanger is not that cheap. I may not need a big one from an efficiency point of view, but Id need one that doesnt clog. Instead I could buy one, or heck, should it prove necessary or useful,  several oil coolers from a car junk yard for next to nothing, or even if you buy them new, something like this:
http://www.ebay.com/itm/UNIVERSAL-15ROW-10AN-TRANSMISSION-RADIATOR-TURBO-ENGINE-OIL-COOLER-ALUMINUM-BLUE-/160721146846?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item256bba13de

isnt gonna break the bank, and I cant see how that would not work when submerged in relatively fast flowing and air bubbling 20-25C water. Like you said, water is a much better heat conductor than air, if it can cool the oil by blowing air over it, its gonna work a hole lot better submerged - I think.

Anyway, Ill probably setup a small scale experiment next month with a single spare card (8800GT) to see what happens. Still have to figure out where to best buy some suitable oil, hoses,  think of a filtration system and come up with a layout thats not completely unworkable. Its not gonna be pretty with all the motherboards suspended inverted above an oil bath, but if it works,  who cares Smiley
1520  Other / Beginners & Help / Re: Submersing a rig on: January 23, 2012, 11:12:51 AM
Okay I did some research myself. Toxicity is not a problem with pure mineral oil. you can even drink the stuff.

As for capacity planning; Lets assume I only submerge my GPUs (thats what I plan, just place them inverted with extenders so only the gpu's "swim"), lets put it at 1000W worth of GPUs in a 100L tank.lets look at the heating of the oil. I found this:

http://make-biodiesel.org/Biodiesel-Chemistry/time-to-heat-oil.html

From the above link:
Time in hours = 0.5 X Number of Liters X Temperature rise in C / by element wattage

Solving that for temperature rise:
Temperature rise per hour = 1000W / ( 0.5 * 100L) = 20C per hour or 0.333C per minute.

Thats considerably less than I would have thought.

Lets assume a hot summer day with 35C ambient air temperature and my pond water being at 25C.

assume the submerged radiator manages to cool the oil to 10C above water temp, so to 35C.
I want the oil in mining rig to remain below 50C. Thats a 15C difference
That means I have to turn over the 100L every 5 minutes. So Id need ~1200L/hour throughput.
Actually, the amount of oil used in the rig theoretically wouldnt matter here.

Anyway, some googling found me this:

http://www.ebay.com/itm/350GPH-DC12V-80C-Brushless-Magnetic-Oil-Water-Pump-/160560267427?pt=BI_Pumps&hash=item25622340a3

Pretty much spot on for the capacity I just calculated, although that probably means its not enough when you factor in pump head and the fact the stated throughput is probably for water, not oil.

Still, seems quite doable with all the above assumptions. Looks like all I need is a pump similar to that one, but probably 2x or so as powerful, some (car) oil radiator and some tubing. Most of the stuff seems fairly inexpensive. Oh and Id need a filter somehow, as there is no way to make this setup airtight if Im only going to submerge the GPUs.

Question that remains; with 50C oil temperature, what would my GPU temps be like? Although it is probably different, can anyone using watercooling shed some light on the relationship between water temperature and GPU temps?
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