cooling

Since boosting my Pi 5 from the default 2.4 GHz clock to 3.14 GHz on Pi Day, I've wanted to go faster. Especially since many other users have topped my Geekbench scores since then :)

In March, Raspberry Pi introduced new firmware that unlocked frequencies above 3,000 MHz for overclocking. This summer, NUMA Emulation patches boosted performance another 5-10% through memory access optimizations.

But even with a golden sample Pi 5, I haven't seen anybody go much beyond 3.1 or 3.2 GHz. The problem seemed to be power supply—the Pi's firmware limits the SoC to a maximum of 1.000V.

...and it's not just for Pi Day.

After posting my deep-dive into the Pi 5's new BCM2712 and RP1 silicon this morning, someone linked me to this GitHub issue: Raspberry Pi 5 cannot overclock beyond 3.0GHz due to firmware limit(?).

For the past few weeks, a few blog readers (most notably, tkaiser—thanks!) commented on PLLs, OPP tables, and DVFS and how something seemed a little off with the 3.0 GHz CPU limit—which was apparently recommended by Broadcom, according to that GitHub issue.

But today, @popcornmix generated a test firmware revision without the 3.0 GHz limit, and zealous overclockers can get to pushing the clocks higher.

tl;dr: 52Pi and Seeed Studio's water cooling solution for the Raspberry Pi 5 can be fun, and works better than any other solution—but at a steep price, and with a number of annoying quirks.

A few months ago, 52Pi reached out and asked if they could send a new water cooling kit they were working on for the Raspberry Pi 5. At the time, the hope was we could figure out a way to get very high overclock with adequate cooling.

Unfortunately—for reasons I'll explore more soon—the Pi 5 can't overclock beyond 3.0 GHz (it's not physically possible). Some of why is explained in my blog post Overclocking and Underclocking the Raspberry Pi 5.

But water cooling is still fun, and the product is in production now, so I figured I'd still give it a fair shot, and see if I thought it might be worth buying for certain niche use cases.

Last year, I wrote a blog post titled The Raspberry Pi 4 needs a fan.

And in a video to go along with that post, I detailed the process of drilling out a hole in the top of the official Pi 4 case and installing a 5v fan inside.

But that solution wasn't great. The fan was a little loud and annoying, and would stay on constantly. And who wants to damage the nice-looking Pi Case by putting a hole right in the top?

From home temperature monitoring to a Kubernetes cluster hosting a live Drupal website, I have a lot of experience running Raspberry Pis. I've used every model through the years, and am currently using a mix of A+, 2 model B, and 4 model B Pis.

The 3 model B+ was the first generation that had me concerned more about cooling (the CPU gets hot!), and the Pi 4's slightly increased performance made that problem even more apparent, as most of my heavier projects resulted in CPU throttling. I've written about how the Raspberry Pi 4 needs a fan, and more recently how it might not.

tl;dr: After the fall 2019 firmware/bootloader update, the Raspberry Pi 4 can run without throttling inside a case—but only just barely. On the other extreme, the ICE Tower by 52Pi lives up to its name.

Three options for keeping the Pi 4 cozy: unmodified Pi 4 case, modded case with fan, and the ICE Tower.

A few months ago, I was excited to work on upgrading some of my Raspberry Pi projects to the Raspberry Pi 4; but I found that for the first time, it was necessary to use a fan to actively cool the Pi if used in a case.

Two recent developments prompted me to re-test the Raspberry Pi 4's thermal properties: