Below is what the connector is, what the author found, and which parts of his account need caveats for anyone planning a build.
What the connector actually is
The Pi 5 exposes a single-lane PCIe interface through a small flat-flex-cable (FFC) connector. It is not a full-size slot. Raspberry Pi's product brief lists it as PCIe 2.0 x1, nothing like the multi-lane slots on a desktop motherboard.
Nothing plugs straight in. Raspberry Pi recommends its M.2 HAT+ or the M.2 HAT+ Compact. Both convert the Pi's PCIe FFC slot to an M Key interface. Without an adapter like that, the connector is just a connector.
NVMe storage: faster, with some setup
Pande's main argument is that an NVMe SSD beats a microSD card or a USB-attached drive for long-running or write-heavy projects. He cites containers that update databases often, and a Windows 11 virtual machine experiment that felt smoother on an SSD. Those are his own observations. The general case is plausible, but your results will vary with the SSD, the workload and the cooling.
His speed figures are 400–500 MB/s by default and 700–800 MB/s with PCIe Gen 3 enabled. Treat them as one user's results, not specifications.
Gen 3 is not a free upgrade
Raspberry Pi documents a Gen 3 switch in /boot/firmware/config.txt. It also warns that the Pi 5 is not certified for Gen 3.0 speeds and that Gen 3.0 connections might be unstable. So the extra speed is real but unofficial. If the board hosts something you care about, test it thoroughly before relying on it.
Using NVMe versus booting from it
Attaching an NVMe drive for storage is simpler than booting from it.
- By default, the PCIe connector is not enabled unless it is connected to a HAT+ device. For other hardware, you add a PCIe-enable line to
config.txtand reboot. - Raspberry Pi says NVMe boot works on the Pi 5 with an M.2 HAT+ or M.2 HAT+ Compact, but needs some additional configuration.
- For the M.2 HAT+, the documented route is to flash Raspberry Pi OS to the NVMe drive with Raspberry Pi Imager. If the OS already runs from an SD card, you can run Imager on the Pi itself and pick the NVMe drive as the target.
- Next, boot from the SD card, run
sudo raspi-config, and under Advanced Options > Boot Order choose NVMe/USB boot. Then reboot. - Non-HAT+ adapters may also need the bootloader's
PCIE_PROBEsetting, which makes it enumerate the PCIe x1 interface for NVMe devices during boot.
If the Pi still boots from an SD card, check the boot order and whether the card is still inserted.
AI acceleration: the AI Kit is a legacy example
Pande uses a first-generation Raspberry Pi AI Kit, which carries a Hailo-8L accelerator, to run Frigate object detection on four cameras. Raspberry Pi's current documentation covers vision AI models on the Pi 5, and LLMs only on the AI HAT+ 2.
Raspberry Pi launched the kit in June 2024 at $70. The accelerator is rated at 13 TOPS. Raspberry Pi's documentation also flagged that the AI Kit was not yet supported by Raspberry Pi OS Trixie. Pande's four-camera result is his own configuration and is not a guaranteed figure.
Anyone building new should look at Raspberry Pi's current AI HAT+ line, not hunt for the older kit. The source packet records the kit as no longer in production. It does not verify the $150–250 price range Pande quotes, which probably reflects aftermarket pricing. Treat it as his estimate.
The SATA NAS idea
Pande also describes using a SATA HAT on the PCIe socket to build a NAS with internal drives. He prefers it to USB-connected external drives, which gave him power and stability trouble beyond about three hard drives. Many SATA HATs have a dedicated power jack, which helps with larger arrays. The source packet does not independently verify the specific boards, so this is his experience.
Cost: the real catch
Pande's cost argument is simple. The connector creates options, but the options cost extra.
- He puts PCIe-to-NVMe adapters at $10–20, more for dual-SSD boards, before the price of the SSD.
- Raspberry Pi's product brief lists board prices of $45 (1GB), $77.50 (2GB), $110 (4GB), $175 (8GB) and $385 (16GB). These are list prices and do not guarantee retail pricing.
- He paid about $90 for an 8GB board with shipping, and says a replacement would cost at least $200. That mismatch with the list price is a reminder to check current pricing yourself.
- He concludes that an average N100 mini PC would be cheaper than a Pi 5 plus HATs, and that it would run more operating systems and offer better hardware and I/O.
None of the Raspberry Pi sources reviewed establishes the mini-PC comparison or the adapter prices. It is a reasonable argument from an experienced tinkerer, but it is an opinion. The documented point is narrower: you need a separate HAT or adapter to use the connector at all.
Who should buy in
- Good fit: tinkerers who want NVMe boot, a compact Frigate box or an internal-drive NAS, and who value the Pi's form factor and GPIO.
- Poor fit: beginners on a tight budget, or anyone who just needs a cheap home server. An x86 mini PC may serve them better.
- Proceed carefully: anyone planning to run Gen 3 for long-term services.
The PCIe connector is a real expansion point, not a promise of desktop-class bandwidth or a free route to a finished NAS or AI box. Budget for the adapter, check the boot and configuration requirements, and treat Gen 3 as an experiment.
Correction (November 3, 2026): The board prices originally listed the 2GB model at $65 and the 16GB model at $305. Raspberry Pi raised the 2GB Pi 5 to $77.50 on October 1, 2026, and the 16GB Pi 5 to $385 on November 2, 2026, both before this article was published; the prices above now reflect those current list prices.