PCIE power / io module power

[T_Minus]

I was curious, can you completely eliminate power usage for a PCIE device by disabling it in BIOS or ??

Example configurations:

- SuperMicro Motherboard with 2-Port Intel 10Gig PCIE NIC
- Intel Motherboard with 2-Port Intel 10Gig NIC as an IO Module

Can you disable/enable power to the module or PCIE slot and even if you do will it still use 1-2w more?

What about a PCIE slot with HBA? If you're powering down drives to save power why not power off the HBA too? Could you tie this into pre-boot power on sequence for storage VMs?

More of a curiosity than a real need Figure someone here would know before I spend time looking through BIOS.

 

[Terry Kennedy]

Figure someone here would know before I spend time looking through BIOS.

I've never seen any PCIe slot power control at the motherboard level, but that doesn't mean there aren't any, just that they're rare. This link (PDF) shows that at least one vendor has a chipset that supports it. Dell built some servers with PCI-X slot power control, to allow hot-swap of expansion cards. OS support was "somewhat" lacking, and drivers didn't respond well to the card disappearing. So they didn't carry that over into newer designs.

 

[T_Minus]

I've never seen any PCIe slot power control at the motherboard level, but that doesn't mean there aren't any, just that they're rare. This link (PDF) shows that at least one vendor has a chipset that supports it. Dell built some servers with PCI-X slot power control, to allow hot-swap of expansion cards. OS support was "somewhat" lacking, and drivers didn't respond well to the card disappearing. So they didn't carry that over into newer designs.

Thanks for the feedback.

I hadn't seen any power control that I could recall either, but my experience with Dell, HP, Intel, etc... is very limited and wasn't sure if it was one of those things that may have come out in the last year or two.

 

[Rand__]

The only thing that comes close are jumpers on the board (hard disable o/c) or NVME power governor from what I have seen.

 

[i386]

Per PCIE specification it should be possible. The only problem is that the L2 & L3 power states are optional and have to be implemented/supported by the vendor of the pcie device.

Source: PCIE 3.0 Specification (http://composter.com.ua/documents/PCI_Express_Base_Specification_Revision_3.0.pdf)