Overclocking Raspberry Pi 5’s SoC To 3 GHz And 1 GHz GPU

October 1, 2023 by Maya Posch 17 Comments

Overclocking computer systems is a fun way to extract some free performance, or at least see how far you can push the hardware before you run into practical limitations. The newly released Raspberry Pi 5 with BCM2712 SoC is no exception here, with Tom’s Hardware having a go at seeing how far both the CPU and GPU in the SoC can be pushed. The BCM2712’s quad Cortex-A76 CPU is normally clocked at 2.4 GHz and the VideoCore VII GPU at 800 MHz. By modifying some settings in the /boot/config.txt configuration file these values can be adjusted.

In order to verify that an overclock was stable, the Stressberry application was used, which fully loads the CPU cores. Here something like a combination of stress-ng and glxgears could also be used, to stress both the CPU and GPU. With the official actively cooled heatsink the CPU reached a temperature of 74°C with a whole board power usage of about 10 Watts. At idle this dropped to 3 Watts at 46°C. At these speeds, the multiple Raspberry Pi 5 units OCed by Tom’s Hardware were mostly stable, though one of the team’s boards experienced a few crashes. This suggests that this level of OCing could still be subject to luck of the draw, and long-term stability would have to be investigated as well.

As for the practical use cases of OCing your Raspberry Pi 5, benchmarks showed a marked uplift in compression and Sysbench benchmark scores, but OCing the GPU had no real positive impact on YouTube or 3D performance, leading even to a massive increase in dropped frames with video playback. This probably means that increasing the CPU clock may be beneficial, but OCing the GPU could be futile without also OCing the RAM frequency, if at all possible.

Realistically, the Raspberry Pi SoCs never were speed monsters, with even the Raspberry Pi 4B’s SoC being beaten handily in 2020 by a budget dual-core Intel CPU. The current Intel Alder-Lake-N-based N100 SoC has a 6 Watt TDP and boosts up to 3.4 GHz while its Xe-LP-based iGPU (with AV1 decoding support) makes for a decent gaming experience within a ~16 Watt power envelope. Clearly, any OCing of the Raspberry Pi boards is more for the challenge of it, but then so is running the latest Intel CPU at 10 GHz with liquid nitrogen cooling.

A Spinning Egg For Your Thoughts

October 1, 2023 by Danie Conradie 16 Comments

Brushless motors are fascinating devices that come in all sorts of shapes and sizes, but you’ve probably never seen one in the form of a free-spinning shiny metal egg. Created by [David Windestål], [Giacomo Di Muro], and [Chad Kapper], the Motion Zero is part top, part brushless motor, and fully mesmerizing. Tech overview video after the break.

Like the classic Tippe Top toy, an ovoid shape like this shiny metal egg will stand on its end if it’s spun fast enough. To do this, the team embedded magnets in the metal egg, effectively turning it into a rotor. An array of 4 PCB coils under a smooth concave surface serves as the stator. Because the egg is not held in position by a shaft, hall effect sensors were incorporated to determine the position of the egg, and properly control the state of the coils to keep it spinning.

Recognizing how easy it was to get lost in thought while staring at a shiny spinning egg, the rest of the device was designed with meditation in mind. The top cover is a block of aluminum machined with ripple patterns, with ball bearings that slide between the ripples as the control interface. Additional hall effect sensors on the PCB determine the position of the balls to adjust the rotation speed and shut-off timer. You can even choose to make the egg move around or remain in one position. The main controller is an ESP32 module, which reads all the hall effect sensors and controls the coils via motor drivers.

The Motion Zero has made its debut on Kickstarter and already exceeded its initial funding goal. We like the creators’ willingness to share the inner workings of a product that manages to transform a simple concept into a mesmerizing piece of engineering artistry.

We’ve seen a good bit of [David Windestål]’s has a fascination with weird tech over the years, like racing belt sanders, fire breathing waterfowl, tri and bicopters. He even built a prop anti-drone RF cannon for a movie.

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