One question we get a lot around here is whether or not ARM is the top choice out there. Of course, ARM hardware is easy to acquire, but in terms of turn key installation, Intel is still much easier to integrate at this point. We did decide to start running the Linux test suite on a few ARM platforms. The first of which is the mega-popular Raspberry Pi 512MB model. We installed Raspbian and tried our Linux test suite. Luckily, almost everything worked, except the crafty chess benchmark. Otherwise, there are certainly some interesting results. Let’s take a look.
Since the Raspberry Pi Model B 512MB platform is pre-configured, we did minimal configuration to the setup. The onboard Broadcom BCM2835 700MHz ARM1176JZFS processor and 512MB of RAM were enough to run a basic web server.
Power was driven by a 2.0A wall adapter. Overall hardware setup time was measured in about a minute. Raspberry Pi’s are easy to get running.
Benchmarking the Raspberry Pi Model B 512MB
First off, this is clearly not the type of workload that one would want to run on a Raspberry Pi. Some of the benchmarks were very slow. We did make one modification. Our crafty chess benchmark would not run using our default test settings so we are not presenting results here for that test.
hardinfo is a well known Linux benchmark that has been around for years. It tests a number of CPU performance aspects.
Here we see the Raspberry Pi Model B 512MB put forth an effort similar to the Intel Atom S1260 in many ways. On another hand, the FPU test is showing the Intel Atom S1260 being about 5x faster.
UnixBench 5.1.3 Performance
UnixBench may be a defacto standard for Linux benchmarking these days. There are two main versions, one that tests single CPU performance on that tests multiple CPU performance. UnixBench segments these results. We run both sets of CPU tests. Here are the single threaded results:
Again, with UnixBench 5.1.3 running in single threaded mode we see the Raspberry Pi 512MB at the bottom of the pack. It is performing in the same realm as the Amazon AWS EC2 t1.micro instance type and the Intel Atom S1260.
When multi-threaded results are run, the key takeaway is that the Raspberry Pi is a single core design. As a result, it does not run a multi-threaded workload.
c-ray 1.1 Performance
c-ray is a very interesting ray tracing benchmark. It provides both consistent results and some clear separation. Ray tracing is generally a great multithreaded CPU benchmark. For this test we use both a simple 7500×3500 render and a more complex 1920×1200 render. Here are the results:
This test is very compute intensive. As a result the Raspberry Pi can run our “simple” render in just under five minutes, or in about 298x the time of the dual Intel Xeon E5-2430L setup. Moving to our more complex render, required because so many modern configurations can handle our first render in 1 second, we see the Raspberry Pi Model B 512MB fall behind in the benchmark. 7243 seconds is just over two hours for the Raspberry Pi rendering. In contrast, the Intel Atom S1260 takes under 22 minutes. A faster setup such as a Haswell based Intel Xeon E3-1220 V3 will run the more complex render test about 181 times faster than the Raspberry Pi.
Phoronix Test Suite Performance
We are using four tests from the Phoronix Test Suite: pts/stream, pts/compress-7zip, pts/openssl and pts/pybench.
- STREAM by John D. McCalpin, Ph.D. is a very well known memory benchmark benchmark. S
- 7-zip compression benchmarks were a mainstay in our Windows suite so we are including it again on the Linux side as a compression benchmark.
- The pts/openssl benchmark is very dependent on the CPU architecture being used
- Python is a widely used scripting language and pyBench is a nice single-threaded Python benchmark.
Here are the results of the Phoronix Test Suite benchmarks:
Here we see again the Raspberry Pi Model B 512MB be more similar in terms of performance to the Intel Atom S1260 or the Amazon EC2 t1.micro cloud instance. One thing we saw putting together the test suite was that the t1.micro’s burst compute speed did skew some results including that of our pts tests.
Overall, the Raspberry Pi Model B 512MB is not the fastest platform around. At the same time, as a very basic web server, it can probably handle the task. If one had a very simple HTML website that received low traffic, there is a good chance the Raspberry Pi could run that workload without an issue. More complex calculations and dynamic image resizing may present more of a challenge. Overall, the Raspberry Pi Model B 512MB is an interesting low power server platform.