Raspberry Pi 3 Model B in detail


The trusty VideoCore IV graphics component of the RPi3 now works with a 300MHz clock rate for the 3D core and up to a maximum of 400MHz. This rate is in contrast to the 250MHz of the predecessor. However, the hardware support for HEVC/x265 decoding is still not included.

On the other hand, the higher GPU clock rate makes MPEG-4 decoding possible at up to 60 frames per second with 1080p video mode. Taken together with the increased CPU performance, this increase results in interesting opportunities for video software decoding. The RPi3, for instance, could use software decoding for MPEG-2 in 1080p, perhaps doing away with a separate codec license. Using the GPU with its higher clock rate and the improved NEON support could make decoding H.265 video compression possible up to a resolution of 720p. In the future this rate could potentially improve to a maximum of 1080p.

The UART changes required by Bluetooth are the only changes to the GPIO pins. Almost all of the GPIO extension modules, or HATS, should therefore be fully compatible with the RPi3.

Temperature and Power Supply

By now, the Raspberry Pi Foundation has acquired a lot of experience with the Broadcom SoC, so the standard clock rate is set significantly higher at 1.2GHz for the RPi3.

The Cortex A53 CPU warms up with a full load on all four cores and without a cover to over 75°C. (The RPi2 normally heated up to 55°C at the most.) When the temperature reaches 80°C, the RPi3 displays a yellow rectangle on the screen and gradually cuts back the clock rate. At 85°C, the SoC lowers the clock rate to the idling frequency of 600MHz.

The user wanting to tease full performance out of the RPi3 should therefore use a heat sink. It is also a good idea to make sure that the cover permits unimpeded escape of heat through properly placed slits and holes. Basically, the RPi3 should work without any problems in an RPi2 case. However, an RPi2 case does not allow an unimpeded view of RPi3 LEDs. An official RPi3 case is available from the Raspberry Pi Foundation.

The RPi3 delivers a nifty 1.2A of power for external USB devices. The setting max_usb_current in the config.txt no longer shows any effect. In view of the increased power consumption of the new SoC and the integrated WiFi Bluetooth combo, the Foundation recommends that the RPi3 have a power supply with 2.5A, which should provide enough current for the CPU cores to crunch away at some task you've given to them.

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