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Raspberry Pi 3 Model B+ Benchmarks, Review, and Comparison

Raspberry Pi 3 Model B+ is the newest offering from the Raspberry Pi Foundation sharing much of the same features as the Raspberry Pi 3 Model B with small but significant improvements on many fronts while maintaining the same price. Below is some highlights.

  • Increased CPU clock speed from 1.2GHz to 1.4GHz
  • Increased memory throughput
  • Integrated Heat Spreader (IHS) for SoC
  • Integrated MxL7704 PMIC for power management and delivery
  • Modularized WiFi/BT Radio with 5GHz and improved performance
  • Gigabit Ethernet (albeit still over USB 2.0)
  • Ethernet headers for PoE addon

We ran a comprehensive set of benchmarks on the new model, old model, and our boards to compare performance and power consumption.

We begin with heavily optimized C applications like C-Ray and SciMark2. Raspberry Pi 3 Model B+ is still utilizing 32-bit kernel and userland like its predecessor. Raspbian, the official OS of Raspberry Pi, has not moved to 64-bit ARMv8 despite the ARM Cortex-A53 CPU cores supporting it. Legacy 32-bit can help performance for this specific benchmark since some data structures and pointers are smaller than in 64-bit ARMv8 mode. Performance increases around 20% from the Model B, which means that the Raspberry Pi 3 Model B+ matches the performance of similarly clocked ROC-RK3328-CC. It is still slightly behind the AML-S905X-CC since that is about 100MHz faster.

Now we move onto server based workloads. Redis is a good test of overall system performance as it stresses not just the CPU but also the interrupt and memory subsystems. We see the Raspberry Pi 3 Model B+ improving greatly in performance over the previous Model B but still not enough to catch up with modern 28nm SoCs with faster DDR3/4 running ARMv8 kernel and userland.

Java benefits heavily from having native 64-bit arithmetic and performs signficantly faster on the boards running true 64-bit OSes. Despite nearly a 30% increase in performance, the Raspberry Pi 3 Model B+ is left behind.

Sysbench results should be taken with a grain of salt when comparing different binaries but this demonstrates the necessity of true 64-bit ARMv8 kernel and userland. Even with the performance gains, Raspberry Pi products are still held back by 32-bit ARMv7 Raspbian OS. Both the Renegade and Le Potato boards deliver more than 10x the performance.

Raspberry Pi 3 Model B+ uses a newly revised BCM2837B0. There are four limiting features of this SoC just like the previous BCM2837 in the Model B. First, it is missing ARM ISA’s Crypto Extensions. For encryption and decryption workloads such as VPN, SSL, SSH, and HTTPS, it’s NEON accelerated implementation is roughly 15x slower. This is one of the critical missing features that make the Raspberry Pi 3 Model B+ a poor choice for server based workloads that depend on these security instructions.

The second limiting feature has to do with the GPU which is a 30-bit design limited to 512MB of RAM. It only supports DDR2 so we haven’t seen the Raspberry Pi move to faster memory like LP/DDR3 like on Le Potato or LP/DDR4 on Renegade. As a result, memory intensive workloads will be much slower although the Model B+ is marginally faster than the Model B.

Like the previous Model B, the Model B+ has not implemented UHS support for MicroSD cards. It is still limited to 25MB/s while other boards are more than twice as fast.

As mentioned by Eben Upton, the Raspberry Pi 3 Model B+ has a single USB 2.0 channel which is shared between the ethernet and four port USB hub. Despite having a physical gigabit ethernet, performance is limited to 320Mb/s (40MB/s) peak. If you are using a USB hard drive serving files over ethernet, the effective throughput is reduced to 160Mb/s (20MB/s). Intensive NAS based use-cases for the Pi continues to be ruled out. ROC-RK3328-CC (Renegade) has both dedicated Gigabit Ethernet and dedicated USB 3.0 so it can deliver an order of magnitude more throughput.

The most horrifying aspect of the Raspberry Pi 3 Model B+ is the power consumption. They’ve learned the wrong lesson from ASUS Tinker Board, Orange Pi, et al. While the new PMIC addressed the voltage drop issues, power consumption shot up 50% for marginal increases in performance. In our previous guess of the Raspberry Pi Foundation’s plans, we assumed Broadcom would help make a power efficient Cortex-A35 design. Instead, BCM2837B0 went in the exact opposite direction.

In our CPU burn tests, the board consumed nearly 1.8A without any peripheral or screen connected. This is at the borderline of the MicroUSB power spec and will un-doubted create new power related headaches for many end-users. Most cell phone power supplies simply will not work for this board.

It would be fair to say that the Raspberry Pi 3 Model B+ will not be winning any performance per watt benchmarks especially compared to the super fast and efficient Le Potato board. However, it is a significant step in the right direction compared to its predecessor. The hardware designers have addressed quite a few long-standing issues and we expect the next generation Raspberry Pi 4 to further amortize design issues.

  1. The new integrated heat spreader (IHS) will allow the Raspberry Pi 3 Model B+ to sustain performance for longer and perform more reliably than the previous Model B. It will help the temperature sensor adequately throttle performance when a specific area of the chip becomes too hot and extend the useful life of the board specially in industrial conditions.
  2. The new WiFi/Bluetooth module performs with excellence. It also uses a module design which saves companies from having to go through expensive radio certification process. In our tests, the WiFi performance on the 5GHz band exceeded performance of the Model B on the 2.4GHz band by five times.
  3. The power delivery and management IC has eliminated the voltage drop across the previous poorly-designed power delivery circuit that was causing power warnings with compliant power supplies. While the added power consumption exacerbates the problem, we still feel that this is a step in the right direction.

You can find all of the performance data that we aggregated on this Google Sheet.

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Performance and Power Consumption Comparison for AML-S905X-CC (Le Potato) and Raspberry Pi 3 Model B

We ran a few benchmarks before to demonstrate the design and performance improvements of the AML-S905X-CC (Le Potato) platform over the Raspberry Pi 3 Model B. Although we’ve released the numbers, we never quite gave any visual presentation of said improvements. Here are some graphs to help you understand the differences.

All tests were done on the latest Raspbian 4.9 Stretch for the Raspberry Pi 3 and Ubuntu 16.04 LTS for the AML-S905X-CC.

The Sysbench CPU test is an useless benchmark for comparing relative hardware performance when using different distros but it does demonstrate architecture advantages of a modern ARMv8 ecosystem over legacy ARM ISA ecyosystems. Raspberry Pi 3’s throughput in combination with Raspbian does not perform well since it is based on ARMv6. AML-S905X-CC with ARMv8 Ubuntu takes less than 1/10th the time to complete the same task.

AES is fundamental to securing communication on the internet and at home. When you browse the websites, transfer files, or use web-enabled applications, you are most likely to be invisibly using AES. AML-S905X-CC supports ARM’s Crypto Extensions for accelerating AES encryption and decryption. With the core crypto extensions, AML-S905X-CC performs 20 times faster than NEON-accelerated AES on the Raspberry Pi 3.

AML-S905X-CC is equipped with DDR3-2133 RAM to cope with the high bandwidth requirements of 4K HDR content. Although Raspberry Pi 3 is advertised as LPDDR2-1066, the performance is reflective of LPDDR2-1333. It is possible that newer batches of Raspberry Pi 3 use quicker DRAM or the foundation updated the firmware to increase the DRAM clock speed since launch.

Two optimized C applications enjoy significant performance improvements. You will see a 25%-50% speedup on most applications due to the increased clock speed. Real world performance will show even greater improvements due to the thermal headroom from the significantly lower power consumption of the AML-S905X-CC. We ran into multiple issues with the Raspberry Pi 3 which we will covered later.

Java throughput increases signficantly on AML-S905X-CC with Ubuntu than with Raspberry Pi 3 with Raspbian. Some of the performance increase can be attributed running in ARMv8 64-bit mode.

Raspberry Pi 3 does not support voltage switching on the MicroSD card. It is not able to enter the SDR104 UHS mode supported by most high performance cards. AML-S905X-CC unlocks this capability and allows read and write operations to be performed more than 3X as fast.

Incredible performance is moot without proper power or thermal budgeting. We cut the power consumption of our boards in half as compared to the Raspberry Pi 3. We carefully optimized the power input circuitry to reduce power consumption and increase stability. Where as Raspberry Pi 3 needs a 5.5V power supply to maintain stable 5V rails during cpuburn-a53, AML-S905X-CC will work without issue even with 4.1V power supply! You don’t have to source an exotic tailor made power supply. Almost any MicroUSB power supply will do.

While running these benchmarks, we noticed significant deficiencies of the Raspberry Pi 3 Model B. At first we thought it was our specific board but it was repeatable on every Raspberry Pi 3 Model B we purchased. Using a programmable DC power supply set for 5.1V was not sufficient to prevent the nasty rainbow square issue at full load. The polyfuse on the Raspberry Pi 3 experienced unexpectedly high voltage drop at just 1.5A. This caused huge inconsistencies in its benchmark results until we determined the cause. We had to drive the MicroUSB plug at 5.55V in order for it to achieve the necessary voltage levels on the 5V rails to prevent firmware clock throttling at full load. This is a startling design flaw for a board that has sold several million units. The design issue is the source of numerous complaints online.

Please note that this is partially comparing Raspbian against Ubuntu so the first sysbench numbers do not characterize the overall CPU performance of the Raspberry Pi. The Raspbian distro is using newer compiler toolchain since it is based on Debian Stretch. When Ubuntu 18.04 with Wayland arrives, we plan to upstream more support for the AML-S905X-CC and do an apples-to-apples comparison based on Ubuntu rather than Raspbian for the Raspberry Pi 3 Model B.

AML-S905X-CC (Le Potato) is available on Amazon USA and via our reseller LoveRPi.

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AML-S905X-CC Geekbench 4 Performance Numbers vs Raspberry Pi 3 and Asus Tinker Board

Screenshot from 2017-06-25 23-13-19
Libre Computer Board AML-S905X-CC
Screenshot from 2017-06-25 23-30-22
Asus Tinker Board
Screenshot from 2017-06-25 23-24-18
Raspberry Pi 3 Model B

Since we got our boards back from manufacturing, we have been hammering at it in our labs with tests and benchmarks. The benchmark numbers above can provide a rough estimate of the performance numbers we expect to see.

All of the benchmark numbers were done in a controlled environment in a case with a 20mm 5V fan. While the Raspberry Pi 3 Model B and our board ran consistently without a fan, the ASUS Tinker Board created a lot of heat and required a fan to get consistent numbers.

The ASUS Tinkerboard maxed out at 2.1A. The high current draw created a 0.7V voltage drop between the MicroUSB pin and the 5V rail. This is the largest delta that we have ever seen and we had to increase the DC supply voltage to 5.25 in order to keep the 5V rail above 4.5V.

Renderscript Performance

ASUS Tinkerboard: 1450
Libre Computer Board AML-S905X-CC: 1150
Raspberry Pi 3 Model B: N/A