The LGA 3647 motherboards go down in price and I managed to buy an Intel S2066ST dual socket motherboard from eBay for ~€250. The motherboard works great and I don’t have any complaints but the “fun” thing is the TPM 2.0 connector.

Intel S2600STBR dual socket LGA 3647 motherboard

Intel LGA 3647 S2600ST TPM 2.0

According to the Intel’s manual, the motherboardd should be compatible with 12-pin TPM 2.0 modules.

https://www.intel.com/content/dam/support/us/en/documents/server-products/Intel_S2600ST_TPS.pdf

A TPM device is optionally installed onto a high density 12-pin connector labeled “TPM” on the server board, and is secured from external software attacks and physical theft.

Intel S2600ST TPM 2.0 installation

The supported parts are supposed to be:

Intel S2600ST TPM 2.0 specs

The only problem is that the AXXTPMENC8 is a 14-pin part and that is also confirmed by another manual: Intel Server S2600ST Product Family.

Intel AXXTPMENC8 TPM 2.0 module Intel AXXTPMENC8 TPM 2.0 module

While the motherboard connector is indeed a 12-pin one.

Intel S2600ST TPM 2.0 connector

I went through dozens of Google search pages and could not find a single picture of a 12-pin Intel TPM module. The documentation has this cryptic history entry:

Corrected # of pins on TPM

Intel S2600ST TPM 2.0 revision history

Please let me know if you have any documentation or info about this mysterious 12-pin TPM 2.0 module.

2024.07.31 Update

Thanks to my Discord member whiskytango9 who found this eBay listing, I have a picture of a 12-pin TPM module. It’s not yet known what is shown in the picture since it is a stock photo, so I will try to clarify things with the seller.

Intel Trusted Platform Module 2.0”, AXXTPMENC8.

12-pin Intel S2600ST TPM 2.0 module

2024.08.07 Update

I asked about this 12-pin TPM module at the official Intel support forum:

12-pin AXXTPMENC8 TPM for S2600ST LGA 3647 motherboard.

Unfortunately, Intel’s customer support is utterly incompetent, so far I have not gotten a single relevant answer and it feels like the support agents do not even read the original post.

Another picture of the 12-pin AXXTPMENC8 TPM, this time from Intel themselves.

12-pin Intel S2600ST TPM 2.0 module