Intel preps for PCIe 6.0 inferno with PCIe thottling driver for Linux — mechanism reduces SSD bandwidth when the drive gets too hot

M.2 SSD.

Intel’s work on developing a PCIe Cooling Driver for Linux users has reached a significant milestone. According to a report published by Phoronix, the driver is ready to merge with the upcoming Linux 6.13 kernel. That means Linux systems packing PCIe storage with thermal challenges should handle better when the updated OS becomes available sometime in November. Such measures will probably become all the more important with PCIe 6.0 on the horizon.

We previously reported that Intel’s dev team was preparing this PCIe Cooling Driver for Linux in May, and now we have the first harvestable fruit from their labor. Tom’s Hardware readers will be aware of the ramp-up in thermal issues with the move from PCIe 3.0 to the current pinnacle of PCIe 5.0 storage. The best SSDs available for PCs and consoles, like the PS5, use PCIe 5.0 technology – but cooling needs to be considered.

With the latest PCIe storage devices, heatsink-laden and actively cooled SSDs have become standard fare. However, driver software can also play an important role—hence Intel’s efforts to prepare the PCIe Cooling Driver for Linux.

The PCIe Cooling Driver will work in several ways. The first releases will help keep thermals under control by reducing the PCIe link speed. In other words, according to the driver description, it “implements PCIe cooling mechanism through bandwidth reduction for PCIe devices. " Maybe the driver should be dubbed the ‘PCIe Throttling Driver’ instead, but throttling is a dirty word in tech.

Roadmap: Throughput doubles every three years (Image credit: PCI-SIG)

With the advent of PCIe 6.0 interfaces and devices, Phoronix reckons the Intel PCIe Cooling Driver could go further. It hints that future-tech PCIe 6.0 storage will also be thermally tamed by reducing the PCIe link width when deemed appropriate by the driver.

The source report says that Intel's PCIe Cooling Driver has been queued into the PCI subsystem’s ‘next’ branch, ready to be submitted among the PCI updates prepared for the Linux 6.13 merge window. When the updated OS goes mainstream, enabling the new PCIe Cooling Driver will be simple via a new ‘PCIE_THERMAL’ Kconfig switch. As we mentioned above, expect the Linux 6.13 kernel in November.

The PCIe 6.0 specification was finalized in 2022, and prototype controllers and physical interfaces were demonstrated in 2023. Commercial PCIe 6.0 devices are still expected to become available before the end of 2024.