PCI Express-Power-Custom Design Circuit
Board Electronic Pcb
All sizes of ×4 and ×8 PCI Express cards are allowed a maximum power consumption of 25 W. All ×1 cards are initially 10 W; full-height cards may configure themselves as 'high-power' to reach 25 W, while half-height ×1 cards are fixed at 10 W. All sizes of ×16 cards are initially 25 W; like ×1 cards, half-height cards are limited to this number while full-height cards may increase their power after configuration. They can use up to 75 W (3.3 V×3 A + 12 V×5.5 A), though the specification demands that the higher-power configuration be used for graphics cards only, while cards of other purposes are to remain at 25 W.
Optional connectors add 75 W (6-pin) or 150 W (8-pin) power for up to 300 W total (2×75 W + 1×150 W). Some cards are using two 8-pin connectors, but this has not been standardized yet, therefore such cards must not carry the official PCI Express logo. This configuration would allow 375 W total (1×75 W + 2×150 W) and will likely be standardized by PCI-SIG with the PCI Express 4.0 standard. The 8-pin PCI Express connector could be mistaken with the EPS12V connector, which is mainly used for powering SMP and multi-core systems.
|6-pin power connector (75 W)||8-pin power connector (150 W)|
|1||+12 V||1||+12 V|
|2||Not connected (usually +12 V as well)||2||+12 V|
|3||+12 V||3||+12 V|
|4||Sense1 (8-pin connected)|
|5||Sense||6||Sense0 (6-pin or 8-pin connected[a])|
^ When a 6-pin connector is plugged into an 8-pin receptacle the card is notified by a missing Sense1 that it may only use up to 75 W.