Read what? Your mind?

I don't see you mentioning this anywhere else in this thread.  Perhaps you've mentioned it several times in other threads, but you shouldn't expect others to read your post history.

I'd expect a 5870 may make up for the minor power difference with a higher per-core hashrate, at least at stock clocks.  5970's are clocked down a bit for the same thermal concerns.

Space being a concern for you, however, means 5970's are a better buy.  They're also more widely available, 5870's are a bit hard to come by these days.

for future reference, you can scale the size of your image in the post, something like:

Temperature variation is the real card killer.   I'd agree with anything < 80-85C, but some cards just don't stay that cool even standing alone with good ventilation and room-temperature ambient environments.

It's more important to make sure your temperatures aren't swaying significantly on a regular basis, the (small) expansion/contraction will eventually stress the metals in your GPU, leading to reduced life.

A stable 80C is far better than swinging between 60C and 80C every day.

The PSU specs (esp on newegg) will show you 'pci-e connector:  6+2pin ' - that's usable in either a 6pin or 8pin socket (the +2)

If this PC of yours only has one PCI-e slot, or you're absolutely certain you won't be adding any more cards to it, that 600W I linked will work solidly for you.

That is assuming you don't also have 20+ hard-drives, 10 fans and a bunch of flashy lights

[edit] Also, avoid using adapters if at all possible.  My general rule of thumb these days is if your PSU doesn't have enough native PCI-e connectors to support all your cards, you should look at a bigger PSU.

That's not exactly a cost-effective suggestion, but you'll quickly learn what you can and can't connect if you start to expand.

I would highly recommend against it.  That PSU can't provide half the power a 5970 wants, and that's not mentioning the other cmponents that want 12V power, namely your CPU.

Symptoms would range from mild to catastrophic..  mild would be it doesn't turn on, or does but is very unstable.  Catastrophic would be the PSU failing and taking out your PC and your new 5970 with it.

I would recommend going with something like this PSU at least:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139028

I think we need some fingerprint analysis on the digit reflected in the kill-a-watt, to be entirely sure that aliens were not involved.

My point was to poke fun at the previous poster who's electricity is leaking onto the interwebs.  Otherwise, we're using the same math.

I fully understand that wattage is a measure of the current drawn at a particular voltage, ala Watt's law:

P (work, or watts)  = I (current) * V (voltage)

But wait! Don't forget that Ohm guy, his law says:

V (voltage) = I (current) * R (resistance)

R is the only element you can normally change.  R is the light bulb, the furnace, the computer, etc, and R determines how much current you draw and how much voltage is dropped along a circuit.  You don't change current or voltage separately.


I forgot what my point was?  Oh yeah!  We're arguing from opposite sides of a balanced equation!  That's just not smart, lets not do that.

[edit] I see, when I said "The same current flows through your light bulbs, but doesn't cost as much since you use less of it as work" I didn't mean to use 'current', but instead 'electric energy' like the last guy.  Typo, my bad.

And perhaps somebody is steaing your water! Watch out!

Electricity cost is calculated on wattage used as work (eg. producing heat), not current flow.  The same current flows through your light bulbs, but doesn't cost as much since you use less of it as work.

That is pretty frakkin' sweet.

Have you had any issues with the OS addressing that many USB devices?  It looks like you've got a fairly good hub which probably presents itself as such to the OS, I've had some crappier hubs that start to complain when you multiplex >4 devices..

Nope, still brown.


Nope, still brown  Less brown, but still brown.

I can see that it's clearly brown, even in the tubing outside of the case where it connects to the radiator.

Those things definitely accentuate the color tint, however.   With more ambient light, a white card behind the tubes, and flash off it looks fairly clear.  It still looks like there's a heavy smoker living in my radiator, and it's still enough to make me want to flush out the system and replacing the tubing.

Prior to this go-round the tubing was a little cloudy/milky white, but it didn't look like literal crap.

It's right at the high water mark running everything at full tilt, so yeah it's a little undersized.  With all three cards mining and prime95 running my killawatt reads 760-780W at the wall.

But, I don't really mine with this rig, and have yet to actually stress the system running any of the games I've tried.  Generally it tops out about 430W on my killawatt playing Skyrim, 550-600W playing Witcher 2 which actually uses all 3 cards a little more.

If I did mine, it'd be in linux without the 100% CPU bug, I'd expect to see ~600-630W at the wall with just the GPUs spinning.

My guess is that it's just not concentrated enough to be obvious in solution, and has been slowly depositing on the tube walls.  In that second pic it's obvious there's a tint, but it wasn't actually visible to me at that point.  I pondered then why my pretty tubing was showing up so badly in the pics. Over the next few days, more material oxidized and/or built up on the tube walls, making it more apparent visually.

Right now, visually the appearance is close to the second pic in my post above, but to the camera it looks like someone shat in the tank:

Aye, the rig was all taken apart with the components lying on a shelf ~15ft away. I'd plugged all the free tubes with cotton since I knew I'd be spitting metal dust everywhere, but it'd seem I wasn't careful enough.

I'm ordering some new tubing this afternoon, I'll be flushing it out and replacing all the tubing when it arrives.  In the meantime, is a little rust going to be a problem for my copper/nickel blocks and rad?

I'm thinking I'll need to take the pump apart and clean it out thoroughly - if it is steel dust it's likely been collecting around the magnetic fields in the motor..

Not knowing the exact specifications of your electric heater it's difficult to give a clear answer.

The best answer is to to buy a Kill-a-watt or similar power measurement device and find out for yourself.

Your electric heater is going to be more efficient at converting electricity to heat than any computer you're running, but it won't also be generating bitcoins at the same time.

[edit] I re-read and see you said 'furnace', I thought you meant a wall-plug type electric heater, a furnace will be a little harder to measure.

Ethnocentric much?

Most of the things you own are from chinese manufacturers.

So the rig has been running for a little while after adding the third card, temps are excellent and performance is stellar, but..

That brown tint in the tubing is actually there - at the time it only showed up like that in the pictures so I assumed it was just poor lighting, but now it actually looks like that - all my tubing is coated with that nasty brown color.

Has anyone run into this kind of thing before?  I did get the usual white clouding that I was more or less expecting prior to this last upgrade, but brown?

I'm using only distilled water and a kill-coil in the reservoir.

I think it's either biological, or some kind of oxidizing contaminant, since it wasn't apparent straight away.. the pics above were all taken at around the same time, and you can see in the top pic there's no apparent brown in the tubing.  The second pic was after bleeding for about 18hr. Scratch that, the second pic was 2 days later.

The only new addition was the third GPU block, it's possible it might have been 'dirty' I guess, and thinking back I'm not sure I flushed it before adding it into the loop, but I didn't flush the first two either and the system ran 'clean' for quite a while.

I don't think (I hope not anyway) that it's biological - the kill-coil should've prevented a colony from forming, and if it were algae I'd expect to see a green or reddish tint, not brown..

Another possibility - at the same time I added that block and refilled, I took everything apart and modded the windows into the case.  There was quite a bit of steel chaff floating around (case was definitely steel, not aluminum), it's possible some of this dust got into the loop.  Would steel oxidize and make this color?

[edit] You might also notice the reservoir is crystal clear in that pic - it still is.  Whatever this is it's not sticking to the acrylic, but it seems to love the tubing.

You're all doing it wrong. 

I kid, I kid.  I've actually taken down my 3.8GH/s setup and sold off most of my parts, after which I built:






But of course it wouldn't be worthwhile without the sexy lights:




This is definitely a game-centric rig:

3x XFX 6950 @ 845/1325
Phenom II 1090T 6-core @ 3.9ghz
Gigabyte 990FXA-UD5
8GB DDR3-1600
2x 120gb SSD in raid-0 (1GB/s!)

I don't do much mining with it, but it'll get ~1.1GH/s all spun up.  At < 40dB.  At < 50C. 

Unless your 300W PSUs are 80+ gold (do they exist?), the 1200W 80+ gold PSU is going to save you a considerable amount of money over time, and there's no short-game in bitcoin mining if you expect any kind of ROI.

That said, an unstable rig isn't doing you any good, so if it's really the only way you can keep it running, so be it.  I have to say there are plenty of miners running multiple cards on larger single PSUs without stability problems, so perhaps this is just bad luck?

I can tell you're probably from northern New York or Vermont from your beer boxes

I moved about 5 years ago and I really miss Saranac.  Black Forest is the bomb!