AMD announced today that it has identified the source of an fTPM-induced system stuttering issue on Ryzen systems and had issued a BIOS fix to motherboard makers. However, the BIOS updates will take some time to make their way to market, with the first arriving in May 2022. In the interim, AMD has also advised using a 'workaround' that employs a discrete TPM key instead of the in-built version inside the processor. Notably, that isn't an option for all systems, especially laptops.
AMD has remained silent on this issue for months, but widespread reports indicate that AM4 Ryzen systems have long been plagued with system stuttering associated with enabling the fTPM (firmware trusted platform module) feature. As a reminder, TPM functionality is a not-strictly-enforced security requirement for Windows 11, but it is also present in Windows 10. The fTPM is a security mechanism available with AMD processors that removes the need for a separate discrete TPM device. Both the fTPM and discrete TPM are designed to accomplish the same goal — store an unchangeable security key, thus enabling a higher level of security. However, the different approaches store the key in different locations.
The fTPM key resides in the SPI flash memory that's present on the motherboard (commonly referred to as a BIOS chip). AMD says the fTPM issue involves intermittent latency introduced by fTPM-related memory transactions with the chip, leading to "temporary pauses in system interactivity or responsiveness." The issue impacts AM4 systems that run the Zen+ to Zen 3 architectures.
AMD's fTPM issues impact both Windows 10 and Windows 11 Ryzen systems, with the typical side effect being random stuttering and lagging that lasts one to two seconds. These periods occur multiple times per day during all manner of workloads, including gaming. They manifest as jerky performance on the screen and interrupted and garbled audio, application hangs, and mouse cursor hitching during the system stutters (you can see an example in the short clip below).
Most users have simply disabled the TPM requirement in Windows 11 to circumvent the issue, but now AMD has fixes coming via motherboard firmware updates (UEFI/BIOS). Those fixes (AGESA 1207 or newer) will take some time to arrive through the normal support channels. As such, AMD also notes that you can simply disable the fTPM feature in the processor and use a discrete TPM device instead. You will need to follow very specific measures during that process to ensure that you don't lose any encrypted data. These devices can be costly, with pricing varying between $20 and $170.
Here are the details in AMD's freshly-issued support document:
- This documentation provides information on improving intermittent performance stutter(s) on select PCs running Windows 10 and 11 with Firmware Trusted Platform Module (“fTPM”) enabled.
- Issue Description
- AMD has determined that select AMD Ryzen system configurations may intermittently perform extended fTPM-related memory transactions in SPI flash memory (“SPIROM”) located on the motherboard, which can lead to temporary pauses in system interactivity or responsiveness until the transaction is concluded.
- Update and Workaround
- Update: Affected PCs will require a motherboard system BIOS (sBIOS) update containing enhanced modules for fTPM interaction with SPIROM. AMD expects that flashable customer sBIOS files to be available starting in early May, 2022. Exact BIOS availability timing for a specific motherboard depends on the testing and integration schedule of your manufacturer. Flashable updates for motherboards will be based on AMD AGESA 1207 (or newer).
- Workaround: As an immediate solution, affected customers dependent on fTPM functionality for Trusted Platform Module support may instead use a hardware TPM (“dTPM”) device for trusted computing. Platform dTPM modules utilize onboard non-volatile memory (NVRAM) that supersedes the TPM/SPIROM interaction described in this article.
- COMPATIBILITY: Please check with your system or motherboard manufacturer to ensure that your platform supports add-in dTPM modules before attempting or implementing this workaround.
- WARNING: If switching an active system from fTPM to dTPM, it is critical that you disable TPM-backed encryption systems (e.g. BitLocker Drive Encryption) and/or back up vital system data prior to switching TPM devices. You must have full administrative access to the system, or explicit support from your IT administrator if the system is managed. For more information on transferring ownership to a new TPM device, please visit this Microsoft webpage.
- COMPATIBILITY: Please check with your system or motherboard manufacturer to ensure that your platform supports add-in dTPM modules before attempting or implementing this workaround.
The fTPM issue follows early performance problems with Windows 11 and Ryzen systems, and the company's fixes for a long-running problem with USB-connected devices.
We had previously reached out to both AMD and Microsoft about the fTPM matter, and both firms told us they were investigating the issues. We're following up with AMD for more information about the scope of the impacted systems. Stay tuned.
