Raspberry Pi Zero 2 W - Quad-core and 64-bit CPU

Everyone has been asking for the upgraded version of Raspberry Pi Zero W since two years ago. Now, it is finally here, the Raspberry Pi Zero 2 W.

The Major Upgrades

Of course, the new revision comes with upgrades :) The most significant upgrade is the CPU.  

The board incorporates a Quad-core 64-bit ARM Cortex-A53 CPU, clocked at 1GHz. At its heart is a Raspberry Pi RP3A0 system-in-package (SiP), integrating a Broadcom BCM2710A1 die with 512MB of LPDDR2 SDRAM. With this upgrade alone, there is a tremendous improvement. Booting into Raspberry Pi OS desktop GUI is 3X faster than the original Zero W board. From our testing, using the 32GB MakerDisk preloaded with Raspberry Pi OS, Raspberry Pi Zero 2 W boots into GUI just within ~20 seconds while the earlier Raspberry Pi Zero W takes ~70 seconds. For single-threaded performance, it is 40% faster than earlier versions too. For multi-threaded, the quad-core performance is 5.2x faster than the single-core CPU.

The RP3A0 is a SiP that wire-bond the BCM2710A1 die with 512MB RAM, and this is done in-house by Raspberry Pi Engineering Team, thus the Raspberry Pi logo and the "RP"30A on the CPU package. Due to the limited space of the Raspberry Pi Zero board and single-layer PCB component placement (to reduce manufacturing process and cost), the CPU and RAM need to be "stacked". Raspberry Pi Zero W (V1) is using BCM2835 as the bottom IC and 512MB RAM is "stacked" on it as Package on Package (PoP). However, as explained by Eben Upton (Founder and CEO of Raspberry Pi Trading) in many interviews, the main constraint in upgrading Raspberry Pi Zero is finding a RAM package that matches the preferred processor die, stacking it to form another PoP. Since there is none in the market, they designed the wire-bond for RP3A0 SiP, how awesome is that? 

Besides the upgrade of the CPU, there is also a slight improvement in the wireless specification. Bluetooth is upgraded to V4.2 from V4.1 while preserving the BLE and WiFi IEEE 802.11 b/g/n (single-band, 2.4GHz). The Raspberry Pi Zero 2 W should deliver better wireless performance with the improved PCB antenna design too. 

Comparing with its Pre-successor

From single core and 32-bit CPU to Quad-core and 64-bit processor, I believe no one can resist it! Grab it while you can find one! I believe it will be hotter than hot cake! 

I have also highlighted the improvements in the Blue text in the above table.

Comparing with Raspberry Pi 3 Model B

Well, the new Raspberry Pi Zero 2 W has the same CPU specification as Raspberry Pi 3 Model B - Quad-core, 64-bit, ARM Cortex-A53. As same GPU - VideoCore IV. What is slightly lacking on the Raspberry Pi Zero 2 W is the RAM size of 512MB and 1GHz clock speed. Both of these boards share the same WiFi spec - single-band 2.4GHz IEEE 802.11 b/g/n. Surprisingly, the new Zero 2 W board comes with a higher spec of Bluetooth standard - V4.2. Not to forget the PCB antenna design that is also better than Raspberry Pi 3 Model B's chip antenna as it is released way back in 2016.  Now, do you think Raspberry Pi Zero 2 W is worth owning one?

Comparing with Raspberry Pi 3B+ and 3A+

Raspberry Pi 3 Model B was released in 2016, it might not be fair to compare a new product in 2021 with it. Let's compare with Raspberry Pi 3 Model B+ and 3A+ :) You will be surprised to know they have the same CPU architecture which is Quad-core, 64-bit ARM Cortex-A53, with 3B+ and 3A+ being clocked at a higher speed of 1.4GHz. For the RAM, again all of them come with DDR2 and  Raspberry Pi 3 Model A+ has the same size as the Raspberry Pi Zero 2 W - 512MB. 

Looking at the wireless spec, Raspberry Pi Zero 2 W comes with Synaptics BCM43436 (Synaptics acquire Broadcom's Wireless IoT Business) that offers single-band (2.4GHz) WiFi of IEEE 802.11 b/g/n. While 3B+ and 3A+ have the AC spec which offers dual-band WiFi of 2.4GHz and 5GHz. Looking at the low power consumption of the Raspberry Pi Zero board, the 5GHz might not be necessary. The IEEE 802.11 b/g/n is more than sufficient for many applications. I have also performed a network speed test with iperf3 on Raspberry Pi Zero 2 W and the result looks good.

I get ~36Mbps, which is similar to the speed I get on Raspberry Pi 3 Model B too. 

Let's not forget about the Bluetooth spec. Raspberry Pi Zero 2 W has the same Bluetooth 4.2 and BLE as both its elder brothers. So now, do you think it is worth getting the Raspberry Pi Zero 2 W? All these upgrades at the cost of USD15.00 (excluding local tax and shipping), grab it while there is stock!

Drop in Replacement

The good news for existing Raspberry Pi Zero/W/WH owners, the new Raspberry Pi Zero 2 W is a drop-in replacement of its pre-successor. The mechanical size, mounting holes, CSI-2 connector, mini-HMDI port, both the USB micro-B ports, microSD card slot, unpopulated 40-pin GPIO pads, and PCB antenna. So most of the accessories for the earlier Raspberry Pi Zero board can be utilized on Raspberry Pi Zero 2 W. 

The OS

Will your OS image on Raspberry Pi Zero/W/WH boots up on the new Raspberry Pi Zero 2 W? As far as we tested, it should be able to boot up as long as you perform an update. We tested with the 32GB MakerDisk microSD pre-loaded with Raspberry Pi OS (May 2021), it boots up without any issue. We have also tested with the 16GB microSD card with NOOBS (V3.6), again it boots up without any problem.

Thermal Performance

Raspberry Pi Zero W does not need a heatsink as the CPU is only a single core. Yet, with the quad-core, 64-bit processor, we might be able to squeeze a bit more power and thermal out of it. Let's run a stress test and look at the result.

I installed stressberry and run it for 15 minutes and this is the CPU temperature and clock frequency against the time chart:

It might get hot and throttle, but we do not normally stress all 4 cores to the full load, so I would say it is safe for it to operate without active cooling or even passive cooling (heatsink). But if you are going to overclock it, which you can :) You will need a good passive cooling or active cooling to ensure it performs well.

Next?

I am looking forward to the enhancement of projects that used Raspberry Pi Zero W/WH (V1) and am very keen to know to what level of improvement can it achieve with the Quad-core, 64-bit CPU while remaining in a compact size. A few projects that I wanted to explore are:

• RetroPie
• OctoPi/OctoPrint
• USB Webcam with Raspberry Pi, and Raspberry Pi Zero V1.3 and Zero W/WH are some of the favorite choices. 
• IoT Home Assistant
• Pi-hole, Network-wide Ad Blocking
• Media Center: OSMC
• Many more... please do share with us once you try it with Raspberry Pi Zero 2 W

Summary

I am getting one Raspberry Pi Zero 2 W when there is ready stock :) You can take your time to wait.