Four motherboard headers that can look pointless in an ordinary PC build are COM, SPI TPM, thermal sensor, and Thunderbolt. Each serves a real but specialized purpose: legacy serial connections, security, temperature monitoring, or an add-in-card route to high-speed I/O. They are examples, not a definitive list of the four least useful headers, and their presence varies by motherboard model.
For example, ASUS lists all four on its PRIME B550-PLUS. That model-specific inventory does not mean every board includes them—or that every accessory will work with every header.
As an Amazon Associate I earn from qualifying purchases.
Why do motherboard makers include headers most builders never use?
A motherboard has to serve more than one kind of build. A connector that is unnecessary for a typical home desktop may still support legacy equipment, a particular security setup, custom monitoring, or an expansion card. ASUS’s H610A-IM-A industrial motherboard manual, for example, documents interfaces including serial, parallel, GPIO, I2C, PS/2, debug, and TPM connections. That shows how requirements differ across boards; it does not establish why a manufacturer chose any one design.
Windows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallOutdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchThese four headers do different jobs, so they are not interchangeable options. Their usefulness depends on what you are connecting and what the exact motherboard supports.
#1 Best Overall
- AMD Socket AM4: Ready to support AMD Ryzen 5000 / Ryzen 4000 / Ryzen 3000 Series processors
- Enhanced Power Solution: Digital twin 10 plus3 phases VRM solution with premium chokes and capacitors for steady power delivery.
- Advanced Thermal Armor: Enlarged VRM heatsinks layered with 5 W/mk thermal pads for better heat dissipation. Pre-Installed I/O Armor for quicker PC DIY assembly.
- Boost Your Memory Performance: Compatible with DDR4 memory and supports 4 x DIMMs with AMD EXPO Memory Module Support.
- Comprehensive Connectivity: WIFI 6, PCIe 4.0, 2x M.2 Slots, 1GbE LAN, USB 3.2 Gen 2, USB 3.2 Gen 1 Type-C
| Header | Task | Separate hardware | What to verify |
|---|---|---|---|
| COM | Provides a serial-port connection for legacy or specialized equipment. | A compatible COM port module and cable. | Board support and module fit. |
| SPI TPM | Connects a discrete Trusted Platform Module for security functions. | A compatible SPI TPM module; many recent systems may already offer firmware TPM. | Whether firmware TPM is available and whether the board supports that exact module. |
| Thermal sensor | Adds a temperature reading from a chosen object or area. | A compatible thermistor cable. | Board support and monitoring configuration. |
| Thunderbolt | Connects a compatible expansion card to provide Thunderbolt connectivity. | A board-supported Thunderbolt add-in card. | Card compatibility and any required PCIe slot. |
What does a COM header do?
A COM header connects a cable to an optional COM port module, which can be installed at a chassis slot opening. ASUS describes this connection in its Z790-AYW WIFI W motherboard manual. The resulting serial port can be useful when working with older or specialized equipment that requires serial I/O. Most ordinary desktop builds do not need to add one.
Before buying a module or bracket, check the exact motherboard manual for the supported connection and installation details. A COM label alone is not proof that a particular module or pinout will match.
Rank #2
- AMD Socket AM5: Supports AMD Ryzen 9000 / Ryzen 8000 / Ryzen 7000 Series Processors
- DDR5 Compatible: 4*DIMMs
- Power Design: 14+2+2
- Thermals: VRM and M.2 Thermal Guard
- Connectivity: PCIe 5.0, 3x M.2 Slots, USB-C, Sensor Panel Link
Do you need a separate SPI TPM module?
An SPI TPM header accepts a compatible discrete Trusted Platform Module. ASUS describes the TPM as a component for securely storing items such as keys, digital certificates, and passwords. That can help protect digital identity and platform integrity, but it does not mean every user needs to buy a separate module.
Free tools Windows power users keep installed
One-click scans. No signup required.
MSI’s guide to motherboard ports and headers notes that recent processors include firmware TPM 2.0, which makes an external module optional for many users. Check your system’s firmware settings and your motherboard’s support information before purchasing an SPI TPM module. The board must support the specific module; do not assume that TPM modules are universally interchangeable.
Rank #3
- AMD Socket AM4: Ready to support AMD Ryzen 5000/4000/3000 Series Processors
- Enhanced Power Solution: Digital 3+3 VRM Design and premium chokes and capacitors for steady power delivery.
- Advanced Thermal Armor: Chipset heatsinks for better heat dissipation.
- Boost Your Memory: Compatible with DDR4 and supports 4 DIMMS with Extreme Memory Profile support.
- Comprehensive Connectivity: 1x Ultra Durable PCIe 4.0 x16 slot, 1x PCIe 4.0 M.2 slot, 1x PCIe 3.0 M.2 slot, 4x USB 3.2 Gen 1 ports for hassle-free setup.
What is the T_SENSOR header for?
A thermal sensor header connects a thermistor cable so the system can report the temperature of a selected object or area. That extra reading may help someone monitor a custom cooling setup or a particular hot spot. It is an optional measurement point, not a required connection for a basic PC. MSI’s motherboard guide discusses thermistor cables, while ASUS lists a thermal sensor header on the PRIME B550-PLUS.
Can a Thunderbolt header add Thunderbolt to any motherboard?
No. The header is one part of a motherboard-specific arrangement for a compatible Thunderbolt add-in card; its presence by itself does not guarantee that an arbitrary card will work. ASUS’s Z790-AYW WIFI W manual directs owners to check the card maker’s compatibility information and identifies a required PCIe slot for that board. MSI also documents a JTBT5 header for its Thunderbolt 5 expansion card, illustrating that supported configurations can differ by board and card.
Rank #4
- AM4 socket: Ready for AMD Ryzen 3000 and 5000 series, plus 5000 and 4000 G-series desktop processors.Bluetooth v5.2
- Best gaming connectivity: PCIe 4.0-ready, dual M.2 slots, USB 3.2 Gen 2 Type-C, plus HDMI 2.1 and DisplayPort 1.2 output
- Smooth networking: On-board WiFi 6E (802.11ax) and Intel 2.5 Gb Ethernet with ASUS LANGuard
- Robust power solution: 12+2 teamed power stages with ProCool power connector, high-quality alloy chokes and durable capacitors
- Renowned software: Bundled 60 days AIDA64 Extreme subscription and intuitive UEFI BIOS dashboard
Before choosing a card, confirm that the motherboard manual and card maker both support the pairing, and check the required expansion slot. Do not infer universal compatibility from the word “Thunderbolt” printed beside a header.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
How should you decide whether to use one?
- Need serial I/O? Check for a supported COM module and verify its installation instructions.
- Considering a TPM purchase? First check whether firmware TPM is available in your system and whether a separate module is actually required for your setup.
- Want another temperature reading? Confirm the board supports a thermistor cable and the sensor input you want to monitor.
- Adding Thunderbolt? Match the add-in card, motherboard, and required PCIe slot using their compatibility documentation.
For any header, use the manual for your exact motherboard model and the supported accessory documentation. Similar labels are not a promise of matching pinouts or compatibility.
Quick Recap
Best Value
- AMD Socket AM5: Supports AMD Ryzen 9000 / Ryzen 8000 / Ryzen 7000 Series Processors
- DDR5 Compatible: 4 x DIMMs with AMD EXPO Support
- Power Design: 16 plus2 plus2, 80A Smart Power Stage
- Thermals: VRM and M.2 Thermal Guard
- Connectivity: PCIe 5.0, 4x M.2 Slots, Dual USB4, Front and Rear USB-C, Sensor Panel Link
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
