cpu

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.

This is the fastest Arm desktop in the world, yes, even faster than the M2 Ultra Mac Pro. And today, I made it even faster.

I upgraded everything: Faster RAM, 128 core CPU, 40 series GPU, I did it all, and we'll see how much we can obliterate the M2 Mac Pro.

128 cores—that's five times more cores, I'm also going to upgrade this thing from 96 all the way to 384 gigabytes of RAM. The Mac Pro? Sorry, it only goes up to 192.

And we're just in time for the new Cinebench 2024 benchmark, which—yes—this machine dominates.

Sometimes life has a funny way of lining up opportunities, and one presented itself when Patrick from ServeTheHome reached out and said, "Jeff, I have an Ampere Altra Max server. You wanna come see it?"

Of course I did.

But seeing as Patrick is more than 800 miles away, I had to come up with a reason to go see it, so I pulled out my 6-node Raspberry Pi cluster—with it's 24 ARM Cortex A72 CPU cores—and decided to have a little competition.

And of course that competition is documented in a YouTube video:

Owing to a mishap with the Pi 4 model B I use for testing—more on how Red Shirt Jeff ruined that board later this week—I had to go buy a new Pi 4 last week.

The local Micro Center only had the 8 GB model in stock, so I went a little over budget and bought it. When I arrived home, I checked the board, and noticed a bit of a difference on the Broadcom SoC:

Can you spot it? The model number of the BCM2711 chip on this board is 2711ZPKFSB06C0T, which is the same as the chip found on the Pi 400.

This is a newer stepping of the original Pi 4 model B chip, which has the model number 2711ZPKFSB06B0T. The difference is the third-to-last character, the C versus the B.

People have been overclocking Raspberry Pis since the beginning of time, and the Raspberry Pi 4 is no exception.

I wanted to see if the Compute Module 4 (see my full review here) could handle overclocking the same way, and how fast I could get mine to run without crashing.

There's a video version of this blog post, if you'd like to watch that instead:
Raspberry Pi Compute Module 4 OVERCLOCKED.

Over the weekend, Nvidia confirmed it would purchase ARM from Softbank for $40 billion.

Now, what is ARM, why is Nvidia buying it, and what does any of this have to do with the Raspberry Pi?

Well, let's start with ARM.

This blog post also has a video version to go along with it.

What is ARM?

ARM can refer to a number of things, but let's start by talking about the company, Arm Holdings. They have lineage dating back to Acorn computers, a British computer manufacturer founded in the late 1970s that designed the first 'Acorn RISC Machine architecture' chips, AKA 'ARM'.

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

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.

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.

December 2020 Update: Lo and behold, the Pi Foundation tacitly acknowledges the Pi needs a fan in the official case, because now they sell the Case Fan!

The Raspberry Pi Foundation's Pi 4 announcement blog post touted the Pi 4 as providing "PC-like level of performance for most users". The Foundation even offers a Raspberry Pi 4 Desktop Kit.

The desktop kit includes the official Raspberry Pi 4 case, which is an enclosed plastic box with nothing in the way of ventilation.