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.

Its a chrome issue. Look here:
http://www.petenetlive.com/KB/Article/0000354.htm

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.

Id be interested in one 5870 and/or the 850W PSU, though that might get more expensive for shipping I imagine.

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 .

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).

Sure, no problem, as long as all the machines are on the same subnet (if you dont know what that is, then they are)

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 .

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.

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 .

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.

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.

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.

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 .


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


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 . 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

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?

A few things.
I just glanced over that wiki, it uses AMDOverdriveCtrl  to set clocks. You dont need that, and shouldnt use that if you use cgminer.

Second remark, dont use keyboard/screen on the miners. There is no need. Assuming you have a network connection, there is this thing called SSH. I am assuming your main PC runs windows, if so just install putty:
http://www.chiark.greenend.org.uk/~sgtatham/putty/

Use it to connect to the miners. Just enter the IP address and set connection type to SSH, and connect (save sessions for each of your machines so its easy to connect to them). You should get a shell, enter ÿour linuxcoin credentials (username="user" and password="live" by default. Note that you dont see anything while typing the password, thats normal).

Next thing you want to do is install a little utility called "screen". That allows you run cgminer over SSH, and close SSH and be able to reconnect to that same "screen" later.

To launch a miner now, just run


You can close SSH now if you want, and if later you want to reconnect to that screen, start the ssh session and run


I see you are using gcminer 2.0.7. its pretty old, you will want to download the latest version. If you need help with that, Ill talk you through it, but lets start by seeing if you manage the above.


As for the rig without lan, let me know what I asked in the other thread about the lights. To troubleshoot that one, we will need monitor and keyboard, unless youd have a spare network card that does work.

Have no stability issues with linuxcoin whatsoever. I just boot it of an USB stick in persistent mode and launch cgminer and it runs and runs and keeps running on both my rigs. Worst thats happened is the GPU crashing when I overclocked too far, all I have to do is restart cgminer- although I read if the first card crashes, you may need a reboot to cure it.  If I add more cards, I also do need to run aticonfig, and then reboot. Thats completely normal.

Anyway, I think you should find out and/or describe more in detail whats happening. Is it just the GPU crashing, is there a problem with the OS or stick perhaps? What do you mean its not starting, is the machine not booting or only the miner app not launching? What cards, miner etc do you use? What clocks on the cards.. You are running this in persistent mode, right?

Do you have leds on the ethernet port? Usually green led means cable+connection is okay, yellow led to indicate activity. Do you get either? If you dont, it looks like a hardware problem. Or if your motherboard doesnt have leds at the ethernetport, check those on your switch/router. To be honest, I think its more likely an issue with router, try resetting that.

Im actually reconsidering my position on this and looking into submerging my rigs for when summer comes.

Here is the thing, I have a large Koi pond (50K liter) next to the shed where I would want to put my miners this summer.  And it wouldnt hurt to warm the pond water during fall and winter, even if the effect will be minimal in the best case. Even with a perfect heat exchange, 2000W is going to do next to nothing to the overall water temperature in the pond, but raising the temperature in the filters is beneficial to the filtering process, every degree helps.

Ill have to expand the filtration system for the pond anyway and  I was considering putting a few large (1000L) settling tanks in the shed. By itself, I wouldnt have expected that to do much, if anything, unless perhaps if I created an air duct of sorts around the miners to concentrate the warm air, and blow that warm air through one of the (open) tanks; i already have a 160L/hour air pump, I could add another one for that purpose. It wouldnt be much of a settling tank anymore then, and I guess it wouldnt do too much to reduce ambient heat either. or?

I guess the more efficient thing to do is submerge my rigs in mineral oil, pump the oil through a radiator which is suspended in a settling tank or filter  tank (Im using 300 liter rain barrels for biofiltering, the filter has a pretty high volume, up to 25K liter per hour).

A few questions, not sure if anyone here can help me with

- how toxic is mineral oil? Or would vegetable oil be better here? I dont fancy the idea of a small leak killing all my fish. I remember reading that a cheap way to buy large quantities of oil for submerged cooling is buying them as... horse laxative. I cant imagine a horse laxative being excessively toxic... ?

- what kind of hoses does one need? Do you need a special kind of rubber or plastic for oil? From the shed to the filtering installation is a fair few meters

- any suggestions on oil filtering?

- does anyone have any idea of dimensioning this? I got no clue how big a pump (pressure and flow rate) or radiator I would need. If it helps, by then I plan on having ~2000W worth of mining gear. The pond water rarely gets over 25C and more typical is 20C  and the water in the filter would have no time to heat up significantly because of the high flow rate. I would *guess* keeping the oil below 35-40C would be good enough to keep the cards reasonably cool, although that is more guesswork on my part.

ANy thoughts or ideas on the matter would be appreciated.

So what you are really saying is that if BFL -as seller- should be "sweating bullets". And you are right, at least if BFL wanted to scam you. Or if you wanted to scam them.

As a customer there is fairly little to be afraid off though. More so since several people have canceled their order and had zero issues getting their money back from BFL. There are already a few 100 pages worth of "discussion" about this on this board, its getting a bit old.

AFAIK, the interface on cgminer doesnt support any of that yet, like pool management or even controlling GPU/fan/clockspeed etc. Its still being worked on. Cant expect those features in anubis before they are even in cgminer.
There are lots of things that can and should be added to it, but this is brand new, and already as it is, I find it extremely useful to be able to monitor my rigs hashrate, temps etc in a single webpage that runs locally on my own machine. Dont have any of the problems you reported btw.

The LT, you are asking for features which are already in cgminer, while dissing as unneeded features which are not (but are in BAMT).
You are aware this is being developed for.. cgminer, right ? .