topic Re: Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake in Embedded Connectivity

Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

etnivor — Mon, 18 Dec 2023 12:06:24 GMT

Hello,

I have a question regarding using INTEL X710-DA2(pcie gen3, x8) in pcie slot 1 which connects directly to cpu.

Is it a design choice to prevent cpu to go to lower package C states when using x16 slot connected directly to cpu?

I have a Asus B760 motherboard with an i3-13100, where if I use the x16 slot cpu package state gets limited to c3.

However if I connect the X710-Da2 to x4 slot to south bridge it all works and my package states goes down to c6.(Card gets limited by the 4x lane though)

I have a chinese mini itx motherboard with an i5-12500H cpu and it has the same issue. Although it only has the x16 slot. I have modded the BIOS and have given me full access to all configuration options, but unable to make it work.

I found a "blogpost" on H770 motherboard which reports the same issues I have using x16 slot.

https://mattgadient.com/7-watts-idle-on-intel-12th-13th-gen-the-foundation-for-building-a-low-power-server-nas/

Is this a design in hardware(CPU) or is it a firmware(BIOS) issue? Can I do anything to make it work?

Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

DeividA_Intel — Tue, 19 Dec 2023 22:55:00 GMT

Hello etnivor,

I do appreciate that you took the time to post in our community forum. I would like to let you know that we have a thread for this kind of inquiry, and a specialist will get in contact with you as soon as possible.

Thanks for your comprehension.

Best regards,

Deivid A.

Intel Customer Support Technician

Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

Yogaeasvaran — Wed, 20 Dec 2023 08:57:16 GMT

Greetings,

Thank you for contacting Intel Customer Support.

We have a dedicated team to support your queries, hence we will transfer to embedded community team.

Additionally, you may create IPS case if you have the Intel Premier Account support.

Regards,

Ryo

Re: Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

etnivor — Thu, 21 Dec 2023 07:35:26 GMT

Thankyou.

Do not have any premier account, awaiting response from embedded team.

Cheers

Re: Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

Diego_INTEL — Sat, 23 Dec 2023 03:56:25 GMT

Hello @etnivor,

Thank you for contacting Intel Embedded Community.

I have been investigating and it seems that it can be fixed from the BIOS, internally I have found this recommendation that worked in Gen 12th and Gen 13th.

"In your BIOS:

Advanced -> Admin -> Chipset->System Agent(SA) configuration->PCI Express Configuration

Set Multi-VC to Disabled on both of PCIE Root Port 1 & PCIE Root Port 2."

Setting Multi-VC to Disabled could help reaching C10, meanwhile, by being enabled, the system can only reach C3.

Also, that link that you have shared was very useful.

I hope this helps in your case.

Best regards,

@Diego_INTEL

Re: Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

etnivor — Sat, 23 Dec 2023 17:33:17 GMT

Thankyou,

will try this on my i5-12500h board when back home after x-mas.

Don't have access to those settings on my Asus board. Will have to mod the Asus bios aswell.

Merry X-mas

Re: Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

etnivor — Mon, 01 Jan 2024 12:27:14 GMT

Hello again,

tried disabling Multi-VC on my Erying i5-12500h motherboard. No luck there, also tried switching to an Intel I226-V nic but same issue. Actually only reach C2 when using x16 slot.

No luck modding Asus bios would need to mod cap file and don't have the tooling todo that. So can not test on the Asus MB.

Cheers.

Re: Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

etnivor — Tue, 02 Jan 2024 12:24:07 GMT

Hello again Diego.

may I ask where I can download Intel FPT tool ?

Nils

Re: Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

Diego_INTEL — Wed, 03 Jan 2024 23:08:06 GMT

Hello @etnivor,

The FPT can be accessed in one document related to the family's processor, in this case, Alder Lake or Raptor Lake, but you will need a Premier account in order to get access to this document.

For example, document #781359 in RDC.

Also, you can check this article:

How to Apply for an Intel® Resource and Documentation Center (RDC) and/or Intel® Developer Zone (Intel® DevZone) Account

https://www.intel.com/content/www/us/en/support/articles/000058073/programs/resource-and-documentation-center.html

Best regards,

@Diego_INTEL

Re: Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

etnivor — Tue, 09 Jan 2024 10:57:32 GMT

Thx,

yes found out CSME tooling wasn't publically available.

Have ordered a flash programmer, should get it at end of month. Then I should be able to mod Asus bios. Will update how it went with Asus board then

Cheers

Re: Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

etnivor — Thu, 15 Feb 2024 20:12:22 GMT

Hello Diego,

took some time until I got around. Had to desolder bios etc.. but have now gotten access to pcie root port settings on my motherboard.

It kind of worked disabling multi-VC on root port 1.

It does not work with the Intel X710-Da2 nic for some reason. Only get to C2.

However it work with an Asmedia1166 pcie sata card, where I get down to c8 which previously only got to c3.

I guess this is an ok solution for me since I can run the x710-da2 nic on an x4 lane pcie slot on southbridge. Unless you have some other tweak I can try

Re: Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

Diego_INTEL — Sat, 17 Feb 2024 04:19:40 GMT

Hello @etnivor,

Yes, that was the only fix I could find, I'm glad that it could help in one board at least, I'm not sure if the design of the other board may affect, there is a different design for deep sleep states, could be the case.

Best regards,

@Diego_INTEL

Re: Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

fanta989 — Tue, 10 Mar 2026 10:25:45 GMT

Hello Diego

I found your post very intresting because i go an i9-13900 with a ROG STRIX Z690-A GAMING WIFI (Rev. 1xx) and can't find under System Agent(SA) configuration ->PCI Express Configuration a button to disable Multi-VC on PCIE Root Port 1 & PCIE Root Port 2.

Bevor i got an i3-13100 with an other Motherboard from Asus, but with the same Problem...
What can I do? Do I need custom BIOS firmware to handle multi-VC? I'm very frustrated....

Best Regards
@fanta989

Re: Re:Using x16 pcie slot disables low package c states ASPM. Alderlake and Raptorlake

etnivor — Tue, 10 Mar 2026 12:15:24 GMT

I had to desolder bios from motherboard and dump it and modify it and flash it back.

I used uefi editor to modify it.

It's possible to modify BIOS in-place but was way to much work and you needed access to none public software.

You will never reach ASUS engineers.