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Too Much Gold Delays World's Fastest Supercomputer
Nerval's Lobster writes "The fastest supercomputer in the world, Oak Ridge National Laboratory's 'Titan,' has been delayed because an excess of gold on its motherboard connectors has prevented it from working properly. Titan was originally turned on last October and climbed to the top of the Top500 list of the fastest supercomputers shortly thereafter. Problems with Titan were first discovered in February, when the supercomputer just missed its stability requirement. At that time, the problems with the connectors were isolated as the culprit, and ORNL decided to take some of Titan's 200 cabinets offline and ship their motherboards back to the manufacturer, Cray, for repairs. The connectors affected the ability of the GPUs in the system to talk to the main processors. Oak Ridge Today's John Huotari noted the problem was due to too much gold mixed in with the solder."
Just give it to me and I'll get rid off the excess gold
ROHS strikes again
pimp you super computer?
I wish I had this problem in my life... too much gold!
Did anyone else go right here?
sudo make me a sandwich
They realized that it had too much gold when they noticed its name was showing as "Titan, of the Shattered Sun"...
Too much gold never slowed down Mr. T. I pity the fool.
... I assumed everybody knew by now you should always go with Monster Cables ! ...or maybe they didn't run them in properly ?
If there is one thing to be learned on slashdot, it has to be sarcasm.
I'm not a chemist either but fortunately somebody who is working on it is.
Munger also reported the problems with the connector pins, which Oak Ridge Today‘s John Huotari noted was due to too much gold mixed in with the solder. Gold is used for connectors because it does not oxidize quickly, and because of its high electrical conductivity; however, when mixed with solder that contains tin, the gold and tin can combine, making the combination brittle (PDF) under certain conditions. Cray is reportedly replacing the connectors to alleviate the problem.
Quoting from the article "Gold is used for connectors because it does not oxidize quickly, and because of its high electrical conductivity; however, when mixed with solder that contains tin, the gold and tin can combine, making the combination brittle under certain conditions."
I can only guess, but perhaps the coating on the terminals has to maintain certain mechanical properties over time. A wrongly formulated alloy, or a wrong thickness of plating will give you a connector that, perhaps, degrades in presence of heat and vibration. Or perhaps it plastically deforms on the contact area, thus lowering the contact pressure and eventually leading to loss of reliable connection. When you have small contact area, the contact pressure is sufficient to provide essentially a gas-tight connection. As the contact area grows, the pressure drops and eventually you expose your contact area to the atmosphere. At that point things usually go wrong.
Pure gold is soft and by itself it has about the worst properties imaginable for any sort of a connector surface. It literally rubs off, it's so soft. Its low resistance is irrelevant, since the gold layer is very thin. Gold's bulk conductance plays little role in overall resistance of a mated contact pair. You could replace gold with a metal that has 10x lower conductance, usually with little or no measurable change in contact resistance -- that is, if you can find something that can match gold in other properties (wetting of underlying surfaces, resistance to oxygen, etc.).
Gold is also useless as plating for high current terminals. I have designed plenty of connectors where some pins were for small signals and were gold plated, and others were for power and were silver plated. Gold plated power contacts simply lose the gold and then you have all the problems of an unplated contact pair that's exposed to the atmosphere since the gold erodes away leaving craters. It's no fun.
When you get relays with gold-plated contacts, there are often two sets of ratings. One is for low-current use, where the gold is guaranteed to stay on the contacts. Another rating is for sufficiently high current use where the gold is vaporized away and you're left with some other coating material that works well in this application. You can't swap such relays around without realizing what's going on, since contact pairs that were exposed to high currents will perform horribly in small signal, small current applications.
I also can't quite understand why people still buy gold jewelry -- all it took for me was a gold wedding band. I switched to tungsten carbide after a decade and I'm not looking back. The standard 18K alloy is a joke.
A successful API design takes a mixture of software design and pedagogy.
What's strange is how the gold got mixed into the solder. Long gone are the days of cheap gold when they would plate every metallic surface on a connector. Now they selectively plate the mating surfaces. Certainly they don't plate the part you solder. Gold contamination of solder is a well known phenomenon, but I haven't heard of it in decades, literally. The only other thing I can figure is that sometimes they flash plate some gold on the PC board to reduce solder whiskers or something. But that's a well known process. What the hell happened here?
cash for gold will offer $10 a board
CONQUISTADOR: Welcome to New Spain! This is your new Father - Father Corona.
FATHER CORONA: Pax vneuti nicutm! down on your knees, now! D'ye recognize what I'm holidn' over your head, lads?
INDIAN: It's a Cross. The Symbol of the Quartering of the Universe into Active and Passive Principles.
FATHER CORONA: God have mercy on their heathen souls!
CONQUISTADOR: What the Father means is - what is the Cross made of? Gold! Have you got any?
No.
Alloys work in mysterious ways. Some alloys are "simple" having properties somewhere between the pure metals. Others have properties significantly different than their components. It can be a very non-linear process, in some cases even a fraction of a percent of "contamination" can drastically alter the properties of a metal, or you may have a "sweet spot" where the properties get better and better until you add just a little to much and change things completely. In this case someone said it was a matter of excess gold making the solder brittle.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Sorry but either your comprehension sucks or your just trolling. They are not "using tin instead of lead", it's an alloy composed of 63% Sn + 37% Pb, ie: good old fashioned tin-lead solder, the abnormally high trace levels of gold is the cause of the problem.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
There was lead in the solder, 37% to be exact.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Oddly enough the solder they are using is 63%tin and 37% lead, the tin is not the "problem" since the problem doesn't occur without the extra trcaes of gold.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
What the hell happened here?
Maybe the Boomer who knew the process inside and out recently retired. I've seen this happen in a few tech/manufacturing industries lately. There's a chance he was hired back as a consultant to fix this mess.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
Did you know that people in North America pronounce "solder" as "sodder"? I had no idea until I moved to the US and I still find it hilarious!
As you add more gold you are changing the properties of the alloy you are forming. A small layer of gold to prevent oxidation doesn't really cause much impact, your solder (in this case eutectic Sn-Pb) still melts and solidifies basically the same way. The more gold you add the more complex the system becomes. Rather than a nice eutectic material that goes from liquid to solid directly, you get different phases that solidify at different temperatures. This results in the formation of brittle intermetallics that fail prematurely.
D6 63 0D 70 89 81 BB 8E 7B 7C 5F 5D 54 EA AB 73
Quote from Wikipedia:
Legislation published in July, 2011 removes these exemptions.
Apart from a few exemptions, RoHS2 covers all types of Electrical and Electronic Equipment (EEE) including some medical devices and monitoring and control equipment which have been exempt in the past. Previous exemptions to product from categories 8 and 9 will be gradually phased out,[16] with:[17]
- Cat. 8: Medical Devices - 3 years after publication
- Cat. 8: In-vitro-Diagnostics - 5 years after publication
- Cat. 9: Control and monitoring instruments - 3 years after publication
- Cat. 9: Industrial control and monitoring instruments - 6 years after publication
The reason stated on Wikipedia for exempting these things in the first place was being cautious until enough experience had been collected, considering that they only constituted only a small part of the electronics garbage pile anyway.