silicon

New 2GB Pi 5 has 33% smaller die, 30% idle power savings

Raspberry Pi launched the 2 gig Pi 5 for $50, and besides half the RAM and a lower price, it has a new stepping of the main BCM2712 chip.

BCM2712 C1 vs D0 Stepping chips

This is the BCM2712 D0 stepping. Older Pi 5's shipped with a C1. In their blog post, they said:

The new D0 stepping strips away all that unneeded functionality, leaving only the bits we need.

Steppings are basically chip revisions where they don't change functionality, and usually just fix bugs, or tweak the layout. But even tiny design changes could have unintended consequences. I wanted to see exactly what happens when I push one of these new chips to the limits.

First, I wanted a performance baseline, so I ran Geekbench with the latest Pi OS and all the defaults.

Die shots and transistor-level debugging on Raspberry Pi 5

Ever since I X-rayed the Raspberry Pi 5 to see inside the BCM2712 and RP1 chip packages, I've wanted die shots of both chips. Why? Mostly out of curiosity, since I'm not a silicon expert by any means.

I also ran into some weird overclocking issues after writing about my experience overclocking and underclocking the Raspberry Pi 5, and probably spent an unhealthy amount of time (and money) to learn about the clocks, PLLs, and chips on the latest version of everyone's favorite Single Board Computer.

Raspberry Pi 5 BCM2712 fragment (Some Raspberry Pi 5s were harmed in the making of this blog post.)

An important consideration about Pi 5 overclocking

Silicon lottery.

Now that the Raspberry Pi 5s been readily available (at least in most regions) for a few months, more people started messing with clocks, trying to get the most speed possible out of their Pi 5s.

Argon THRML Tower Cooler installed on Raspberry Pi 5 for Overclocking test

Unlike the Pi 4, the Pi 5 is typically comfortable at 2.6 or even 2.8 GHz, and some Pi 5s can hit 3.0 GHz (but no higher—more on why tomorrow well... this limit may be able to be lifted).

After some testing, I found the default 2.4 GHz clock on the Pi 5 is pretty much the efficiency sweet spot, and after a lot more testing recently, I can confirm that's still the case, testing a number of Pi 5 samples.

What does Apple Silicon mean for the Raspberry Pi and ARM64?

Note: There's a video version of this blog post available here: What does Apple Silicon mean for the Raspberry Pi and ARM64?

Apple Silicon and the Raspberry Pi

A couple weeks ago I tried using the latest Raspberry Pi 4 8 gig model as my main computer for a day, and I posted a video about my experience.

Besides many diehard Linux fans complaining in the comments about my apparent idiocy caused by being a Mac user, the experience taught me one thing: A lot of software still isn't built for 64-bit ARM processors, or even for Linux in general.

But there's one trend that I'm seeing: most of the open source software I use already works great on a Pi 4 running on its 64-bit ARM processor.