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SARPi Project - Slacking on a Raspberry Pi
Raspberry Pi 2 Model B Review
The Raspberry Pi 2 Model B is the second generation of Raspberry Pi single-board microcomputers. It succeeds the Raspberry Pi Model B+ and was released on 02 February 2015. It has an identical form factor to the previous Raspberry Pi Model B+ and is also completely compatible. At first glance it looks almost the same as its predecessor, the Model B+. The best news is that Slackware Linux runs as stable and as reliable as ever on the device. So, what's new and interesting about this 'next-gen' Raspberry Pi 2?
On closer inspection you'll see the RAM chip is no longer mounted on top of the SoC. It has been relocated to the underside of the board, and it's a 1GB chip. You'll also notice there's a new Broadcom BCM2836 SoC incorporating a quad-core 900MHz ARM Cortex-A7 processor with ARMv7-A architecture. The Raspberry Pi 2 has a new engine, faster and more powerful than before. This enables it to run the full range of ARM GNU/Linux distributions, which of course includes Slackware, with much greater speed and efficiency. The amount of RAM has been doubled to 1GB and runs at a clock speed of 450MHz, which is 50MHz faster than previous models. This was an area where the Raspberry Pi Model B and Model B+ were lacking due to their limited (and somewhat slow) single-core 700MHz ARM11 CPU with only 512MB RAM available. So this next-gen Raspberry Pi 2 with its quad-core CPU and 1GB DDR2 RAM is a beast in comparison and its capability and potential has increased exponentially. Raspberry Pi Ltd. have stated that the Raspberry Pi 2 is around 6 times faster than the Model B+. Even Microsoft have announced support for the Raspberry Pi 2 with their Windows 10 operating system. So that goes some way towards explaining just how much the Raspberry Pi 2 has advanced and differs in comparison to previous models while retaining full compatibility, identical functionality, form-factor, and price!
The cost of a Raspberry Pi 2 Model B is exactly the same as the Model B+ (US $35 / GBP ~£25 / Euro ~€30 - ex tax).
Raspberry Pi 2 Model B (top view - microSD card slot and RAM chip are underneath)
You'll find the same 4x USB 2.0 ports, HDMI connector, audio/composite jack socket, ethernet port, and power socket, as on the Model B+. All of the connectors are in the same place with the same functionality, and the board can still be run from a 5V micro-USB power adapter. Having the same form factor means the Raspberry Pi 2 fits into any existing Model B+ case or enclosure. It also incorporates advanced power-saving features with a variable CPU clock speed which drops the core from 900MHz to 600Mhz when idle. The best thing of all is that the Raspberry Pi has advanced from having a single-core 700MHz ARM11 CPU with 512MB RAM to a blistering quad-core 900MHz Cortex-A7 CPU with 1GB RAM and yet retains the same price as the Model B+.
"Is the Raspberry Pi 2 worth buying if you already have a Raspberry Pi Model B and/or Model B+?"
The answer is, "Yes! It's like going from a Fiat Cinquecento into a brand new Jaguar F-Type!"
Raspberry Pi 2 Model B Hardware Revisions
There have been a number of revisions to the Raspberry Pi 2 Model B since its initial launch. Depending on the hardware revision of the device, these subtle distinctions can include; different manufacturer and place of origin, different manufacturer of RAM chip, and upgraded BCM2837 SoC.
To find out the hardware revision of your Raspberry Pi(s), use this command, as 'root' user, at the command prompt:
The currently available Raspberry Pi 2 Model B revisions are:
| HW Revision | RAM | PCB Rev | Release Date | Manufacturer |
| a01040 | 1 GB | 1.0 | Q1 2015 | Sony (UK) |
| a01041 | 1 GB | 1.1 | Q1 2015 | Sony (UK) |
| a21041 | 1 GB | 1.1 | Q1 2015 | Embest |
| a22042 | 1 GB | 1.2 | Q3 2016 | Embest |
Raspberry Pi 2 Model B Spec's
Features:
• System-on-a-chip (SoC): Broadcom BCM2836
• CPU: Broadcom BCM2709 Quad-core ARM Cortex-A7 (ARMv7-A) @ 900MHz
• GPU: Broadcom VideoCore IV,OpenGL ES 2.0,OpenVG 1080p30 H.264 high-profile encode/decode
• RAM: 1GB LPDDR2 SDRAM @ 450MHz
• Micro Secure Digital / microSD card socket
• Size: 85mm x 56mm x 17mm
• Power source: 5 V (DC) via Micro-B USB socket or GPIO header
• Power consumption: 650mA (3.0W) up to 1.8A @ 5V
Connections:
• HDMI 1080P socket
• 4x USB 2.0 socket
• Push-push type Micro Secure Digital / microSD card socket
• 10/100 BaseT Ethernet socket
• 3.5mm audio out/video out jack (composite video requires 4-pole adapter)
• CSI camera port for camera
• DSI display port for touch screen display
• Micro-B USB power socket
• 40 pin General Purpose Input/Output (GPIO) pins, Serial Peripheral Interface Bus (SPI), I²C, I²S, I2C IDC Pins, Universal asynchronous receiver/transmitter (UART)
For those interested in further information on the Raspberry Pi 2 Model B see this link and for speed comparisons see the RasPi.TV - Raspberry Pi 2 Power-Performance page.
