HalloweenWeed @brknhead; What KMoore is saying, is this: When you make more connections in a series (in-line) circuit, you add more points of failure, and each will add to the circuit resistance if a bad connection. Series: -----(XXX)-----(XXX)-----(XXX)-----(XXX)---- But with a parallel circuit, the primary current flow will travel in the path of least resistance, so any single-point bad connection will simply cause the current to flow in another path. This is somewhat head-scratching, since by this logic the vid cards should start drawing near 100% power from the vid card PCIe power plugs, the ones you plug directly into the vid card; when the 24-pin ATX begins to develop a bad connection. Possibly at that point, then the other 12V devices on the mobo draw enough power to continue the 24-pin meltdown? IDK. A parallel circuit is much harder to draw with lines of text, I will not attempt.
HalloweenWeed ZachA In the picture below it shows a parallel circuit, which allows MULTIPLE paths for current to reach more then one device, A common example that every one hates are christmas lights, YES christmas lights, because if you dont buy parallel lights you will most likely find out that once ONE light in the series dies the rest will not light, but if the lights are in parallel it will allow the rest of the lights to stay lit because it is able to bypass the failed connection LOL, sorry Zach. No in that case the cause of the power failure is usually that the circuit is shorted (to ground). That is a different story, not related to bad connections. The rest of your post is spot-on, but this is a bad analogy - not the same thing. The "black out" occurs when the "hot" wire touches a ground or other grounded object, like a tree for instance. There are "fuseable" connections, that disconnect when too much current moves through them, once this opened, disconnecting that portion of the power grid, the rest of the grid then gets proper voltage again, then the power is restored - except to that portion. That is what you experience when the power "winks." Nice try though. "A" for effort.
ZachA In the picture below it shows a parallel circuit, which allows MULTIPLE paths for current to reach more then one device, A common example that every one hates are christmas lights, YES christmas lights, because if you dont buy parallel lights you will most likely find out that once ONE light in the series dies the rest will not light, but if the lights are in parallel it will allow the rest of the lights to stay lit because it is able to bypass the failed connection
mikotan Quick question as i plan to upgrade one of my current rigs Halloween. I'm thinking of getting a gt580 ftw HC from evga. Will be using it on an e759 rig. Will be getting only one card for now with moderate oc. And maybe a 2nd card in the future for sli. Will I experience the atx burn? (note: i am currently running 2x gtx 285 oced to 775mhz with no problem for 2 years)
mikotan Although i do get the crux of the matter, i am unsure of the parameters within which the atxburn will occur for say the gt580. How much increase in mV or oc will this problem likely manifest itself? It might be noteworthy to find these numbers if possible. Thanks in advance.
TIGRCS ...PCI Express devices with multiple power sources specifically control how much power is taken from each source. I've assumed that because I don't know how else these devices could be expected to stay within PCI Express specs (75w max draw per PCI Express x16 slot IIRC)...
TIGRCS What would be the best way to determine whether or not this is caused by current taking the path of least resistance?
TIGRCS Just checked the temps on pins 10 and 11 of my P7P55-based systems (using a UEI DT304 temp logger with type K thermocouples). Both systems gave the same temps despite having different video cards with different power draws. In both cases, pin 10 read ~120°F and pin 11 read ~113°F. One system has a pair of GTX 470s while the other is a pair of GTS 450s. The 450s should draw a combined ~160W, the 470s a combined ~430W, yet the pin temps were the same. Note that the P7P55 WS Supercomputer has no auxiliary power connectors. Now, to give context to why I've assumed that the cards specifically determine how much power they get from which sources, consider the power consumption test results at XBit Labs for the the cards I have: GTS 450, GTX 470. If you look at more reviews, you'll find many cards, old and new, taking up to but not beyond a limit of 3A from the PCI Express slots. The main exception is "green" cards (ironically) that have no auxiliary power connectors. I'm not trying to disprove your hypothesis, but rather looking for clarification.