Hi I’ve been trying to figure out how much wattage the PCIe 2.0 x4 can deliver?
I’m pairing it with a 12vdc 10 A PSU. So the board itself should be sufficiently supplied. However I’m not certain for how much the PCIe lanes will deliver. I don’t believe that it would supply the full 75 watt as an x16 lane is able to.
I hope someone knows the answer, and is willing to enlighten me.
I managed to find the answer in pci express card electromechanical specification revision 2.0
Table 4-2: Add-in Card Power Dissipation
Not quoted, but interpreted :
Initial power up max
X1 = 10watt, X4/8 = 25watt, x16 = 25 watt.
If add in card configured as high power device:
X1 = 25watt, X4/8 = 25watt, x16 = 75watt.
These limits appear to be the same in the newer revisions 3.0 and 4.0. I haven’t look at 5.0 though.