Gloriously Impractical: Overclocking The Raspberry Pi 5 To 3.6 GHz

November 18, 2024 by Maya Posch 9 Comments

The Raspberry Pi 5 board strapped to a liquid nitrogen cooler and with ElmorLabs AMPLE-X1 power board attached. (Credit: Pieter-Jan Plaisier, SkatterBencher.com) — The Raspberry Pi 5 board strapped to a liquid nitrogen cooler with an ElmorLabs AMPLE-X1 power board attached. (Credit: Pieter-Jan Plaisier, SkatterBencher.com)

As impractical as most overclocking of computers is these days, there is still a lot of fun to be had along the way. Case in point being [Pieter-Jan Plaisier]’s recent liquid nitrogen-aided overclocking of an unsuspecting Raspberry Pi 5 and its BCM2712 SoC. Previous OCing attempts with air cooling by [Pieter] had left things off at a paltry 3 GHz from the default 2.4 GHz, with the power management IC (PMIC) circuitry on the SBC turning out to be the main limiting factor.

The main change here was thus to go for liquid nitrogen (LN₂) cooling, with a small chipset LN₂ pot to fit on the SBC. Another improvement was the application of a NUMA (non-uniform memory addressing) patch to force the BCM2712’s memory controller to utilize better RAM chip parallelism.

With these changes, the OC could now hit 3.6 GHz, but at 3.7 GHz, the system would always crash. It was time to further investigate the PMIC issues.

The PMIC imposes voltage configuration limitations and turns the system off at high power consumption levels. A solution there was to replace said circuitry with an ElmorLabs AMPLE-X1 power supply and definitively void the SBC’s warranty. This involves removing inductors and removing solder mask to attach the external power wires. Yet even with these changes, the SoC frequency had trouble scaling, which is why an external clock board was used to replace the 54 MHz oscillator on the PCB. Unfortunately, this also failed to improve the final overclock.

We covered the ease of OCing to 3 GHz previously, and no doubt some of us are wondering whether the new SoC stepping may OC better. Regardless, if you want to get a faster small system without jumping through all those hoops, there are definitely better (and cheaper) options. But you do miss out on the fun of refilling the LN₂ pot every couple of minutes.

Thanks to [Stephen Walters] for the tip.

New 2 GB Raspberry Pi 5 Has Smaller Die And 30% Lower Idle Power Usage

August 30, 2024 by Maya Posch 16 Comments

Recently Raspberry Pi released the 2GB version of the Raspberry Pi 5 with a new BCM2712 SoC featuring the D0 stepping. As expected, [Jeff Geerling] got his mitts on one of these boards and ran it through its paces, with positive results. Well, mostly positive results — as the Geekbench test took offence to the mere 2 GB of RAM on the board and consistently ran out of memory by the multi-core Photo Filter test, as feared when we originally reported on this new SBC. Although using swap is an option, this would not have made for a very realistic SoC benchmark, ergo [Jeff] resorted to using sysbench instead.

Naturally some overclocking was also performed, to truly push the SoC to its limits. This boosted the clock speed from 2.4 GHz all the way up to 3.5 GHz with the sysbench score increasing from 4155 to 6068. At 3.6 GHz the system wouldn’t boot any more, but [Jeff] figured that delidding the SoC could enable even faster speeds. This procedure also enabled taking a look at the bare D0 stepping die, revealing it to be 32.5% smaller than the previous C1 stepping on presumably the same 16 nm process.

Although 3.5 GHz turns out to be a hard limit for now, the power usage was interesting with idle power being 0.9 watts lower (at 2.4 W) for the D0 stepping and the power and temperatures under load also looked better than the C1 stepping. Even when taking the power savings of half the RAM versus the 4 GB version into account, the D0 stepping seems significantly more optimized. The main question now is when we can expect to see it appear on the 4 and 8 GB versions of the SBC, though the answer there is likely ‘when current C1 stocks run out’.

Cost-Optimized Raspberry Pi 5 Released With 2 GB RAM And D0 Stepping

August 19, 2024 by Maya Posch 42 Comments

When the Raspberry Pi 5 SBC was released last year, it came in 4 and 8 GB RAM variants, which currently retail from around $80 USD and €90 for the 8 GB variant to $60 and €65 for the 4 GB variant. Now Raspberry Pi has announced the launch of a third Raspberry Pi 5 variant: a 2 GB version which also features a new stepping of the BCM2712 SoC. This would sell for about $50 USD and feature the D0 stepping that purportedly strips out a lot of the ‘dark silicon’ that is not used on the SBC.

These unused die features are likely due to the Broadcom SoCs used on Raspberry Pi SBCs being effectively recycled set-top box SoCs and similar. This means that some features that make sense in a set-top box or such do not make sense for a general-purpose SBC, but still take up die space and increase the manufacturing defect rate. The D0 stepping thus would seem to be based around an optimized die, with as only possible negative being a higher power density due to a (probably) smaller die, making active cooling even more important.

As for whether 2 GB is enough for your purposes depends on your use case, but knocking $10 off the price of an RPi 5 could be worth it for some. Perhaps more interesting is that this same D0 stepping of the SoC is likely to make it to the other RAM variants as well. We’re awaiting benchmarks to see what the practical difference is between the current C1 and new D0 steppings.

Thanks to [Mark Stevens] for the tip.

A New Raspberry 5 DSI Cable Makes Using Screens Easier

July 10, 2024 by Lewin Day 8 Comments

Arguably the greatest strength of the Raspberry Pi is the ecosystem — it’s well-supported by its creators and the aftermarket. At the same time, the proliferation of different boards has made things more complicated over the years. Thankfully, though, the community is always standing by to help fix any problems. [Rastersoft] has stepped up in this regard, solving an issue with the Raspberry Pi 5 and DSI screen cables.

The root cause is that the DSI cable used on the Raspberry Pi 5 has changed relative to earlier boards. This means that if you use the Pi 5 with many existing screens and DSI cables, you’ll find your flat ribbon cable gets an ugly twist in it. This can be particularly problematic when using the cables in tight cases, where they may end up folded, crushed, or damaged.

[Rastersoft] got around this by designing a new cable that avoided the problem. It not only solves the twist issue, but frees up space around the CPU if you wish to use a cooler. Thanks to modern PCB houses embracing flexible boards, it’s easy to get it produced, too.

This is a great example of the democratization of PCB and electronics production in general. 20 years ago, you wouldn’t be able to make a flex cable like this without ordering 10,000 of them. Today, you can order a handful for your own personal use, and share the design with strangers on a whim. Easy, huh? It’s a beautiful world we live in.

DietPi Version 9.1: Now With Raspberry Pi 5 Support And More

February 26, 2024 by Maya Posch 11 Comments

DietPi recently released version 9.1, which among other changes includes new images for the Raspberry Pi 5, Radxa Rock 4 SE and NanoPi R5S/R5C & 6. The Radxa Rock 4 SE image was necessary because the Rock 4’s RK3399 SoC is subtly different from the RK3399-T’s SoC in terms of memory support, which prevents a Rock 4 image from booting on the Rock 4 SE. Meanwhile the Raspberry Pi 5 image is all new and still a bit rough around the edges, with features like the changing of the resolution and camera module support not working yet. These new images are all available for testing.

We covered DietPi previously with their 8.12 release, along with the reasons why you might want to use DietPi over Armbian and Raspberry Pi OS. Essentially DietPi’s main focus is on performance combined with a small installed size, with the included configuration tools and the setup allowing for many more features to be tweaked than you usually find. If the performance improvements, lower RAM usage and faster boot times seen with the Raspberry Pi 4 holds up, then DietPi can just give the Raspberry Pi 5 a nice little boost, while saving power in the process.

Thanks to [StephanStS] for the tip.

Raspberry Pi Changes HATs

December 11, 2023 by Jenny List 22 Comments

Following on the heels of their Raspberry Pi 5 launch and some specifications for their RP1 all-in-one peripheral chip, the Raspberry Pi folks have now released an update to the HAT peripheral hardware specification reflecting the new model. Called the HAT+, it represents a major step forward with some significant changes.

Most visible will be changes to the mechanical specification, for while the original HAT specification was very rigid this new version is much looser. A HAT+ must only mate with the 40-pin connector, including the ID pins, and line up with only a single mounting hole compared to the four on the original. Electrically, a HAT+ must recognise the standby power state in which the 3.3-volt line is powered down while the 5-volt line remains active, while software-wise, there are changes to the content of the ID EEPROM including the ability to inform about stackable smaller HATs.

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Raspberry Pi 5 Goes Under The X-ray

December 10, 2023 by Jenny List 1 Comment

Most Hackaday readers will know to some extent what lies inside their computer, even if this is only at a block diagram level listing the peripherals. But what is physically on a modern computer board? [Jeff Geerling] has subjected a Raspberry Pi 5 to a medical imager, and shares with us the many layers of parts and PCB he found there. With a six-layer board and a heap of large BGA chips on it, there’s a lot to look at.

For readers who are used to working with printed circuit boards, it’s likely the techniques involved in the design will not be new. For us, the magic lies in the scale. The sheer number of interconnects on the board is impressive enough, but when it becomes possible to peer into the SoC package it becomes evident that there’s an internal PCB with some of the smallest vias we have ever seen. [Jeff] goes on to show us part by part around the board, on the way reminding us that some of the earliest Pi boards had to be reworked to replace Ethernet jacks without magnetics.

There’s a beauty to these ghostly images which might not be apparent to anyone who hasn’t stared obsessively at a PCB in a CAD package while it takes shape. The images show the work of the PCB designer’s art at a fine scale. We’d almost go as far as to suggest they be viewed as fine art instead of industrial design. Take a look, the video is below the break.

If this art is a bit big for you, then look at ASIC design – which takes things down to the microscopic level of the doped silicon structures within these amazing chips.

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