Topic: XBTec Announce. New ASIC manufacturer. - page 16. (Read 131821 times)

Bitmain has poor communications IMO, but still they are succeeding.

Just because you didnt get paid. You see, we never know until we see the miner (demo maybe?)

There's absolutely no correlation between temperature induced boiling like in 2-phase immersion cooling (no moving mechanical parts) and cavitation (caused predominantly by mechanical moving parts).

Temperature induced boiling like used in the 2-phase immersion cooling is excess energy which changes liquid to vapor. The vapor forms bubbles which have a lot of stored heat energy and higher pressure than the surrounding liquid. Therefore bubbles will rise up and some even grow when merging, but they will NOT just collapse on their own. Or otherwise we would see the same damages of cavitation on all cooking pots, pans, etc. as well and those will not show any effect even after decades of boiling water.

The damaging cavitation you are referring to are caused by low pressure, e.g. pumps, turbines etc. creating a very fast flow of liquids (e.g. venturi effect). Like it is possible to boil water on Mount Everest with very low air pressure at much lower temperatures, the actual energy put into those bubbles is only very little. But as soon as the surrounding liquid pressure takes over with turbulences etc. over the temporary low pressure, then the cavitation occurs. The energy in the bubbles is too little to sustain their state and caused only by temporary low pressure, unlike temperature induced boiling where bubbles have a lot energy insider to carry vapor to the surface. That's why you will always see cavitation damage in connection with pumps, turbines, valves, etc., but NOT temperature induced boiling.

Here's a good article describing it:
http://www.pump-zone.com/topics/pumps/centrifugal-pumps/when-bubbles-dont-burst-why-cavitation-damaging

jimmothy took exactly the right text part out of the Wiki article on cavitation. Since the DIFFERENCE is being described between boiling and cavitation, they are NOT the same as the bubbles are created differently (temperature vs. low pressure). Cavitation does not occur with temperature induced boiling. On the other hand, oil cooling uses pumps to circulate oil to and from the heat exchanger, so yes - there might be cavitation around the pump impellers just as mentioned on Wiki and all the other links where pumps or anything with an impeller / propeller causing fast moving liquid pressure differentials.

On toxicity and evaporation and all other arguments on that it's not practical - one of the many articles on the web:
http://www.pcworld.idg.com.au/article/542462/intel_sgi_test_full-immersion_cooling_servers/
Does it mean that Intel, SGI, U.S. Naval Research Laboratory, Lawrence Berkeley National Laboratory, Schneider Electric, etc. are all wrong, suicidal and have no idea what they're doing? Interesting... maybe you could make much more money by teaching all their PhD's, etc. a lesson in physics and chemistry and prove they're all wrong...

Guys, if you want to use scientific arguments, then please apply those correctly and not make any unfounded statements where correlation is not proven. At high school we've learned how racists tried to use pseudo-scientific arguments to claim that black people are less intelligent, because they allegedly have their hair roots outside of their head and their hair is growing inwards into the head, leaving less space for the brain... Everyone can make (false) claims, but please provide scientifically backed sources / experiments / case studies with sufficient large sample sizes to prove your point.

Constant exposure != a frikin fire extinguisher that you may never use...

Btw, what's that ambient temp of the room where this liquid is?  Remember your chemistry? Escape velocity for vapours etc... Etc...

Do you know what a safety factor is? Bad things happen once its breached. The page says 'yeah its less than the dangerous dose + a bit... when its at this specific %'. That doesn't mean the vapour itself is safe, it just means under that dilution its safe. The safety factor would be 100x-infinity if it was actually safe.

We already know cavitation is a real thing. Now prove it exists in immersion cooling.

Here's a quote from wikipedia:



You mean this guy, 3M, IBM, Intel, Allied control, Coolermaster, Zotac, etc..


That is simply not true.

Have you ever spilled liters of water in a room and seen it evaporate within minutes? Although heat of vaporization is much lower than water, it still takes a lot of energy to vaporize.

With some simple safety controls there should be no problem with toxicity.

Again, if the people at allied control/3m are living in this stuff, it can't be so harmful.

Nonsense.

http://solutions.3mae.ae/wps/portal/3M/en_AE/3MNovec_APAC/Home/Support/Safety/

This page explains the safety pretty well.

As for cavitation, I know it exists.

What I don't know is whether it exists in 2-phase immersion cooling but I do know that it's not a problem because extensive testing has shown it's not a problem.

Cavitation is effect, which happens when liquid boiling and vaporize. Cavitation damage large bearings and turbines. Cavitation damage even huge turbines and bearings, which made from the metal. So, what will happen with PCB Boards after 1 year using?
Need proofs? Okay
Photo of damaged turbine
Issue from Princeton University
Cavitation Damage


this guy on the picture just playing on public.

Actually, it is not so ethically to promote your product in others thread. I did not said anything about that before, but you may create your own thread and promote it there.

For instance, if we pour some 3M liquid on the table - it vaporize out less than 1 minute.
If system suddenly get leak and 250-300 liters will vaporize , how can service staff fix this problem without respirator?

To add to this:
If you look up the data sheet of Novec based fire extinguishers, look in the toxicity section. It says its 'safe'. Look at the methodology. The acute 4 hour poisoning is 'safe', which means given the assumptions it has a 60-120% safety margin. This goes entirely out the window when you're dealing with a warehouse full of the stuff.

that is reason, they can not get safety certificate, and probably will never get it.
If large volume of liquid leak... it could be lethal dose. This liquid is ether in fact.

if you have never heard about cavitation damage, it does not mean this problem is not exists
Sources:
http://en.wikipedia.org/wiki/Cavitation#Cavitation_damage
http://www.engineersedge.com/pumps/cavitation.htm

Looking forward to the release.

Noted.


Its some of the best for large scale implementations, for now at least.

Hey again.
During this time we were faced with some technical problems.
These problems has been solved successfully

To Dogie: we will send device to you nearest days.

Thanks for understanding

0,75 Watt per Gh lackluster, the price certainly your high, who would buy the mining machine

That is Phil, and the other hungover guy in the back is me. 48h in airplane, airport, hotel, jet legged, etc ;-)

Is that phil?

https://www.youtube.com/watch?v=ivVoANqFBuY

^ Very informative video about 2-phase immersion cooling from phil.

Rest assured he doesn't know what he is talking about. Boiling is not cavitation.  Cavitation is the sudden formation and violent supersonic collapse of vapor bubbles following quick swings in pressure such as one encounters in the water flowing from pressure to suction side of a propeller or impeller in water.  It can also be cause by tortuous bends in pipes, etc, anywhere a volatile liquid flows through wild pressure gradients.  

And no, nobody needs to wear respirators and tanks are routinely wide open

jimmothy is right, Novec is also used as fire extinguisher, including operating theaters and other places, and also a couple of medical applications. I'd be rather worried about a few of the hundreds of fumes that are released when a PCB burns down or an ATX power supply, cable, connector etc.

No, not yet.

Got a source for that? I've never heard of such claims.

Novec extinguishers are supposed to boil and release a shit ton of vapor so I can't imagine they would use it if it was toxic.

Not to mention that the vapor leakage would be so small in any decent immersion system that it would be neglegable even if it was moderately toxic (which it's not as far as I know)

If novec was so toxic how do you explain Allied Controls DC which can be visited without the need for gas masks? They use an open bath system so vapor is constantly leaking in to the air. And iirc their offices are connected to the DC so they are practically living in the vapor.

Also if cavitation is such an issue how do you explain Allied Controls system which ran smoothely for 6+ months?

Have you receive the miner yet dogie?