Raspberry Pi 2-generation B-type performance limit test

I. Introduction to the 2 generation of Raspberry Pi

The Raspberry Pi Foundation released the latest version of the Raspberry Pi on February 2, 2015, with a model of 2-generation type B. This new product is not a simple upgrade, but on this single board machine has given a tremendous change. Since its inception in 2012, the Raspberry Pi has undergone several updates and upgrades, from the initial increase of 256MB memory to 512MB, to the subsequent introduction of B +, configuration and performance has improved a lot, but the only constant is the CPU and GPU, That is, the BCM2835 system with integrated ARM11 processor and Videocore IV GPU is always used, "the same formula, or the familiar taste".

So where is the new Raspberry Pi 2 generation better than its predecessors? The answer is that the older version of the BCM2835 system was replaced with a specially customized BCM2836 for the Raspberry Pi, in addition to the perimeter specification upgrade. This new SOC integrates with the new arm CORTEX-A7 four-core processor, each with a high operating frequency of up to 900mhz! Compared to the older single-core 700MHz ARM11 processors, there is a significant leap in the performance of the processor in theory! Of course, to match the new processor, the Raspberry Pi 2 generation of memory increased to 1GB, the operating frequency of 450MHz, than the original B + 512MB 400MHz memory is one times larger, faster.

Perhaps some people will ask, so "forcing lattice" to improve so much, the price is certainly more expensive? The answer is no, Raspberry Pi 2 and B + prices are exactly the same! I think the foundation was bleeding this time. 2-generation Raspberry Pi.

Here is a comparison of the Raspberry Pi 2 with the previous versions:

　　

The Raspberry Pi 2 generation inherits the B + 40pin Gpio interface, and the pin distribution and the B + and A + are identical, so all development projects and external GPIO cards can be used on these three boards. The modules designed specifically for the A-and B-series can be used for Raspberry Pi only, unless the module is not compatible with B-plus, such as piface for Raspberry Pi 2 generation.

The Raspberry Pi 2 generation also complies with the Hat specification, which means that future external boards require integrated EEPROM (electrically erasable read-only memory) to allow the Raspberry Pi 2 generation of external devices to be quickly identified and configured for easier use. The hat specification was introduced in 2014 to the B + edition of Raspberry Pi, although it has not yet been fully popularized, but it is believed to be the Raspberry Pi default standard in the near future.

Second, Raspberry Pi 2 generation performance limit test

Raspberry Pi 2 is a very mature single-board machine and has enough processing performance, can easily be used as a standard PC to use, and now we have a small test of its performance.

The following tests use 8GB Micro SD cards, run the Raspbian operating system, and start all test programs from the desktop. For different versions of the Raspberry Pi software has also been upgraded to the latest version (upgrade method: sudo apt-get update,sudo apt-get upgrade)

The only difference between the Raspberry Pi 2 and B + tests is that the kernel image, the kernel.img file in the Micro SD card boot partition, is compatible with the old Raspberry Pi ARM11 processor. For Raspberry Pi, the foundation has changed to arm CORTEX-A7 processors, so a new kernel image, now kernel7.img, is needed to fully exploit the power of the 4 processor cores.

2.1 Start-up Time Test  

　　This test compares the time required for the Raspbian system installed on Raspberry Pi 2 and B + from start to display the login prompt:

Boot to display prompt	The time required
Raspberry Pi 2	17 seconds
Raspberry Pi B +	33 seconds

It is clear that the Raspberry Pi 2 's start-up time is about half the B +, and it seems to have improved a lot.

Then adjust the boot configuration via Raspi-config and let the two Raspberry Pi start directly to the desktop, the test result of the start time is as follows:

boot to desktop	time required
Raspberry Pi 2	21 seconds
Raspberry Pi B +	42 seconds

Similarly, Raspberry Pi 2 is a step faster than B +, and the speed of ascension is naturally more important than any other upgrade.

2.2 Computational Performance testing  

The following tests will push the power of the two Raspberry Pi to the limit, and the tools used are for Sysbench in Linux environments. The Sysbench has a complete set of test options that you can use to test your computer's extreme performance. The tool can be installed on the Raspberry Pi by executing the sudo apt-get install sysbench in the terminal program.

style= font-family Yahei '; font-size:16px; " > version	time required
Raspberry Pi 2	195.9543 seconds, 3 minutes 16 seconds
Raspberry Pi B +	1331.6552 seconds, 22 minutes and 12 seconds

The test is to let the processor calculate all the prime numbers within 20000, thereby maximizing its performance to the limit. It is clear that Raspberry Pi 2 has scored 3 minutes and 16 seconds to win the B + 22 minutes and 12 seconds. The performance of its processor cores is self-evident.

The following test uses a tool called Memtester. Memtester can check any errors in the computer's memory by performing a series of integrity checks to maximize the performance of the memory. Usually such tests will only return test results, but in order to reflect the time spent on the test, additional time instructions are added.

memtester installation command for sudo apt-get install Memtester and sudo apt-get install time, execute sudo time memtester 256M after installation is complete. The purpose of executing memtester with superuser privileges is to ensure that the storage blocks that need to be tested are specifically locked for testing purposes. The test capacity here is 256MB and runs only once, which means that you can't test all of the storage space on the Raspberry Pi because the operating system itself consumes part of the memory. (To test all storage spaces, you need to use the Memtest86 tool, which can start running before the operating system loads, but unfortunately the tool is not available for Raspberry Pi), the following is the test result:

version	time required
Raspberry Pi 2	1560.99 seconds, 26 minutes 1 seconds
Raspberry Pi B +	4208.09 seconds, 10 minutes, 8 seconds

Raspberry Pi 2 generation only took 26 minutes and 1 seconds to complete the test, faster than the B + 44分钟7秒, the gap is not general big!

To be more complete, several other tests are needed to look at the performance of the Raspberry Pi 2 generation for daily work, and the test results are as follows:

Test Project	Raspberry Pi 2	Raspberry Pi B +
minecraft– loading a new scene	21 seconds	42 seconds
Python 3– Open Application	4 seconds	13 seconds
Sonic Pi--Open application	11 seconds	21 seconds
libreoffice– opening a new text file	9 seconds	18 seconds
Epiphany browser– Open Google	8 seconds	13 seconds

Conclusion

　　The above tests found that the new Raspberry Pi 2 generation was indeed much more performance-enhancing than its predecessors, and the price remained the same. In fact, Raspberry Pi 2 rarely has the need to "full fire" situation, even in the open Minecraft this quite consumes processor resources of the game, the CPU usage is rarely more than 50%, and in the same case, B + has reached 100%. You might think, does this mean that a generation B + and A + are going out of the market? No, these two old products are still in use, especially in industrial applications where there is no need for Raspberry Pi 2, for example, several robot projects are based on a + development.

　　The Raspberry Pi Foundation said it had planned to launch the product many years ago, but it took two years and about 3 million pounds to do research and development before it came true. However, "Do not experience the wind and rain, how to meet the Rainbow," from the above data, the Raspberry Pi 2 McCartney as a single-board aircraft fighter is not too much, it is certain that there will be more and more developers, using this only credit card size of the computer to complete their outstanding projects and works!

Raspberry Pi 2-generation B-type performance limit test