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Like people, computers have their own destiny – and it often develops in different ways. Some lead a measured life and quietly retire at the appointed time. Others are destined to write their name in history, become a recognized legend and even give rise to a whole subculture. The fourth revision of the popular single-board Raspberry Pi leaves no chance for skeptics: the English microcomputer is with us seriously and for a long time.
Having received the affectionate nickname "raspberry", RPi has become a kind of ZX Spectrum for the modern era. Parallels can be drawn for a long time: both computers were born in England (and not just anywhere, but in Cambridge!), Both were intended primarily for education, but at the same time they easily “outgrew” the allotted framework. Being not the most productive for their time, they attracted users with affordable price, simplicity and, of course, community support.
Though the founder of the Raspberry Pi Foundation Eben Upton and until he received the title of knight from the English queen, as was the case with Clive Sinclair almost forty years ago, there can be no doubt that the public recognition of his merits is yet to come. It is possible that after a couple of decades, one of the new generation of hackers and programmers will warmly remember his first Raspberry microcomputer, which helped to decide on the path of life. Yes, Linus Torvalds studied programming at Sinclair QL if you did not know!
An artistic-historical film about Sir Clive Sinclair and the development of the first microcomputers at Sinclair Research movie micro men with Martin Freeman in one of the main roles. The success of his other work – the series “Sherlock” – did not get this picture, but if the fate of the IT pioneers interests you at least a little, the film is definitely worth watching.
I think now you understand why I just could not pass by Raspberry pi 4 and acquired this single-payer as soon as it appeared in our free sale and top of the range. As far as I know, there have been no official deliveries to Russia, but the resellers fussed in time and delivered a few "raspberries" for the most impatient enthusiasts. It's time to find out what the current update has prepared for us!
Curious details can be found already in the configuration. The board is not packaged in an antistatic bag – and this is strange. Eben Upton mentioned that his team is trying to reduce the cost of production of the Raspberry Pi as much as possible, but this is some kind of too radical optimization of costs. You expect to see similar savings when applied to Raspberry Pi Zero for $ 5, but not to the flagship model for $ 55.
However, all these are trifles of life, which you immediately forget about, barely having read the paper instructions. You probably already know that the fourth version of the single-board comes with different amounts of RAM to choose from. In the summer, the Raspberry Pi Foundation announced the appearance of three options at once, with LPDDR4 chips with a capacity of one, two or four gigabytes. But the instructions mention another version, which, apparently, did not reach the release – as much as eight gigabytes! Wow!
There was not a word about it in the news, and we can only guess for what reason the developers decided to abandon such a model. It is possible that the final cost of the “raspberry” with such a memory chip turned out to be too high and did not fit into the philosophy of a cheap computer that Cambridge is trying to adhere to. In addition, do not forget that the release of a new generation in several versions at once is a bold experiment and no one in the organization knows yet which model will ultimately turn out to be the most popular among users.
In such a situation, postponing the release of the version by eight gigabytes and assessing the demand for its closest analogue with four is a logical step. So the likelihood of the release of an even more productive Raspberry Pi remains, especially since the developers have yet to somehow fix the hardware compatibility problem with some power supplies (more on that below).
Further inspection of the microcomputer itself did not bring such unexpected surprises. As stated, the form factor remains the same, but the location and set of connectors have changed a bit, which is why the single-board has lost backward compatibility with some of the old accessories. In the history of the Raspberry Pi, this happened, by the way, for the first time, except for the original models with full-sized SD cards. Was it worth it?
The first thing that catches your eye is that the RJ45 connector for gigabit Ethernet was swapped with a pair of USB ports, moving it closer to the PoE pins. Of course, such a change was obvious and only made the board layout easier. By the way, now the network and peripherals of USB hang on separate interfaces. Prior to that, they were united by a common hub, which created problems with simultaneous use.
In addition, we finally got two ports of the USB 3.0 standard, without it in 2019 it would be completely sad. This means that it is now possible to connect external SSDs and other modern high-speed peripherals like webcams with a resolution of 4K. You can even assemble your own budget NAS, since a combination of USB 3.0 and gigabit Ethernet has some kind of folly – for example, RAID on an SSD. By the way, the VIA VL805 chip responsible for the USB communicates with the processor via PCI Express, and enthusiasts almost immediately found way Work with even faster NVMe drives by simply removing the USB hub from the board. Cool hardware hack!
On the side, the full-sized HDMI connector was removed, replacing it with a couple of Micro-HDMI 2.0. Alas, they stand close to each other, and because of this, connecting adapters with thick connectors on the tails will be inconvenient. But now it’s now possible to display the image on two displays at once. The manufacturer immodestly writes in announcements that “up to two displays and up to 4K @ 60” are supported, but in fact you have to choose: either two displays at 30 frames, or one, but with a smooth image.
Compared to the tiny connectors on the video interfaces, the old-school 3.5mm audio jack seems huge. Surprisingly, the engineers not only decided to save it, but also did not begin to throw out the opportunity to output an analog video signal to it! So everyone can try to breathe life into old TVs and emulate retro games on an authentic screen.
But the developers said goodbye to the Mini-USB connector, now in its place you will find USB Type-C. According to the creators, this allows you to feed a new "stone", the appetites of which grew to 3 amperes under load – a total of an impressive 15 watts of consumption. How true such bold statements are, we will definitely find out a little later, but for now I’ll just notice that the implementation of the USB Power Delivery standard on the new board has broken compatibility with some other users (including me) with the current power supplies. If this problem is critical for you, you should wait for the next revision of the board, in which the developers promised to fix the defect.
The microSD slot was left in its rightful place. If you were counting on a new generation of built-in flash drive (like on the RPi Compute Module, for example), alas, oh – the hopes were not destined to come true. I'm also a little disappointed, to be honest. On the Raspberry Pi 2, this connector was not the most successful design – and on my motherboard it loosened after a while, so that the system successfully booted from the memory card every other time.
The GPIO pin pins have also not changed. On the one hand, this allowed us to maintain compatibility with existing expansion cards, which is nice. On the other hand – as before, the RESET output signal is lacking for a forced reboot of the system (for example, automatically using a supervisor chip). In addition, it would be nice to have at least a couple of additional USB interfaces on this connector – so that it is convenient to use the peripherals that are not supposed to be reconnected too often (such interfaces can almost always be found at the bottom of ordinary desktop motherboards).
Most SoC: BCM2711
However, the most interesting changes occurred, of course, with the central processor. now this SoC BCM2711 with four cores Cortex-a72 based on ARMv8 architecture, which brings system performance to a qualitatively different level. Previous models were based on cores from Cortex-A7 (Raspberry Pi 2) to Cortex-A53 (Raspberry Pi 3+), that is, with this update, developers jumped several steps at once.
First of all, the transition to the 28 nm manufacturing process contributed to this. Chips on all previous single-board versions were manufactured using 40 nm technology, and with the BCM2873 on the RPi 3+, engineers ran into limitations on the crystal area. More productive cores required more transistors, which simply had nowhere to place. As you can see, while Intel and AMD unsuccessfully storm the threshold of 10 nm when developing processors on x86, others – more modest – companies feel quite comfortable on already proven and long-running technical processes.
Currently, documentation for the BCM2711 chip is not publicly available, but you can partially satisfy your curiosity by reading manual on the Cortex-A72.
As for the periphery, the new system on a chip got at its disposal an accelerator of three-dimensional graphics Videocore VI (500 MHz, 2160p). There is also little information on the GPU now, and one can only hope that after some time Broadcom will support the community and lay out the corresponding reference, as happened with Videocore IV on the second anniversary of the Raspberry Pi project. Nevertheless, Eben Upton has repeatedly stated that their ultimate goal is to make single-board as open as possible over time.
I will go through the most important points of what I noticed when working with RPi 4.
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