Yes, but if I remember correctly the issue is that they don’t make sure to limit the current per pin, but to let electricity decide which path to choose. So for some it might be 2A and for others 16A for example.
It depends on the board. Some boards have balancing circuitry, some board can only detect overcurrent on individual wires, and some can only detect total overcurrent (through the shunt)
It is a combination of multiple issues. This is one of them
Bussing the connection on the card side means no balancing of currents between pins, like you said. Older cards dont do it per pin but do divide it into several input rails which are individually monitored for current / voltage differences and will disable the card if it exceeds a certain threshold.
Usually cards would use larger pins on the older 8 pin pcie power cables, which can handle more current and will make better contact in addition to being easier to seat fully without jamming and keep retained.
Additionally they tend to use multiple connectors (e.g. 2x8 pin connectors = 8 pins for +12V), with lower power allowed per pin for more headroom. This means higher current capability and less potential for failures
For example, a standard 9070xt with a 304W TDP may use 2x8 pin connectors. Larger pins, more pins and lower tdp, with current balancing/monitoring on board. It comes out to 3A per pin at full load when the pins are rated for something like 9A.
Your calculation is correct, but just in case anyone not versed in electric circuits is reading: It’s 47.92/6 not 47.92/12 because the other 6 pins are ground (the “return” path for the electricity, it’s a circuit after all).
50 amps through those skinny wires? I’m no engineer but eve I can see that’s going to get hot.
Shoulda used fibre. Glass is naturally insulating.
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I think it would only be five amps.
Tdp for a 5090 is 575W / 12V = 47.92A
At 12 pins (2x6) thats ~8A per pin (47.92 / 6)
Yes, but if I remember correctly the issue is that they don’t make sure to limit the current per pin, but to let electricity decide which path to choose. So for some it might be 2A and for others 16A for example.
It depends on the board. Some boards have balancing circuitry, some board can only detect overcurrent on individual wires, and some can only detect total overcurrent (through the shunt)
I’ll take the one that balances correctly please.
It is a combination of multiple issues. This is one of them
Bussing the connection on the card side means no balancing of currents between pins, like you said. Older cards dont do it per pin but do divide it into several input rails which are individually monitored for current / voltage differences and will disable the card if it exceeds a certain threshold.
Usually cards would use larger pins on the older 8 pin pcie power cables, which can handle more current and will make better contact in addition to being easier to seat fully without jamming and keep retained.
Additionally they tend to use multiple connectors (e.g. 2x8 pin connectors = 8 pins for +12V), with lower power allowed per pin for more headroom. This means higher current capability and less potential for failures
For example, a standard 9070xt with a 304W TDP may use 2x8 pin connectors. Larger pins, more pins and lower tdp, with current balancing/monitoring on board. It comes out to 3A per pin at full load when the pins are rated for something like 9A.
So, uh, money-grubbing in manufcturing?
There’s always money in the banana plug factory.
I had one burn up on a 1070
Your calculation is correct, but just in case anyone not versed in electric circuits is reading: It’s 47.92/6 not 47.92/12 because the other 6 pins are ground (the “return” path for the electricity, it’s a circuit after all).
So definitely not 50a.
PC PSU output 3, 5, and 12V
50 amps at 12 volts would be 600 watts. The GeForce RTX 5090 draws 575 watts at full load. That is some FireWire.
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Are you going to be running 120 volts into your graphics card? That would be brave
Probably better with 120 volts versus 1200.
I think most of us have 12, but between 120 and 1200 I’d choose the latter because it would be more fun
That’s certainly no XT60 on the end!