3 ms·

TGP for 5090 is 575W. PCIe slot supplies 75W, so it's 500W through the connector 500W / 12V = 41.7A, or 52A with 80% derating rule. Conductors should be 10AWG o

TGP for 5090 is 575W. PCIe slot supplies 75W, so it's 500W through the connector 500W / 12V = 41.7A, or 52A with 80% derating rule. Conductors should be 10AWG or thicker. What are go-to connectors at these currents?

BenjiWiebe 2y ago
You'd usually have multiple wires and split the current up. Also, if you design carefully you can let your wires get hotter than what would be recommended for in-wall wiring (what the calculators usually figure for). If you know you'll have airflow, and the insulation is rated better, you could run them hot.
- bestouff 2y ago
  Well, obviously you can't run them so hot ...
AlotOfReading 2y ago
For PC components, molex mini-fits. Not sure exactly which product lines the 5090 specced, but you can get them with 10A+ per circuit.
- numpad0 2y ago
  But its cousin Micro-Fit is what melted, and it's been happening for a while, so infinitely parallelizing these sounds a bit sketchy to me.
  - eqvinox 2y ago
    The resistance thermal coefficient of most¹ materials is positive, which is why parallelizing connectors works; contact points that heat up due to poor contact increase in resistance and therefore current shifts to other connections that have less resistance. This is a plain case of having not enough contact area (or not having enough mechanical safety/UX to ensure full insertion.) ¹ most: pretty much everything that isn't explicitly researched/chosen for its negative coefficient. Definitely all conductor and connector materials. But some semiconductors are known footguns for not supporting parallelization due to negative coefficients and runaway heat effects (one of the things you learn in EE education). P.S.: materials with negative thermal coefficient don't turn into superconductors if you heat them far enough; the coefficient is not constant across temperature and it's either just not linear and approaches some nonzero value, or it just flips to a positive coefficient at some higher temperature. Or the material just melts or burns and then behaves differently anyway.

BenjiWiebe 2y ago

You'd usually have multiple wires and split the current up. Also, if you design carefully you can let your wires get hotter than what would be recommended for in-wall wiring (what the calculators usually figure for). If you know you'll have airflow, and the insulation is rated better, you could run them hot.

bestouff 2y ago
Well, obviously you can't run them so hot ...

AlotOfReading 2y ago

For PC components, molex mini-fits. Not sure exactly which product lines the 5090 specced, but you can get them with 10A+ per circuit.

numpad0 2y ago
But its cousin Micro-Fit is what melted, and it's been happening for a while, so infinitely parallelizing these sounds a bit sketchy to me.
- eqvinox 2y ago
  The resistance thermal coefficient of most¹ materials is positive, which is why parallelizing connectors works; contact points that heat up due to poor contact increase in resistance and therefore current shifts to other connections that have less resistance. This is a plain case of having not enough contact area (or not having enough mechanical safety/UX to ensure full insertion.) ¹ most: pretty much everything that isn't explicitly researched/chosen for its negative coefficient. Definitely all conductor and connector materials. But some semiconductors are known footguns for not supporting parallelization due to negative coefficients and runaway heat effects (one of the things you learn in EE education). P.S.: materials with negative thermal coefficient don't turn into superconductors if you heat them far enough; the coefficient is not constant across temperature and it's either just not linear and approaches some nonzero value, or it just flips to a positive coefficient at some higher temperature. Or the material just melts or burns and then behaves differently anyway.