Raspberry Pi 4: How much RAM do I need?

The Raspberry Pi 4 is the first model to offer different amounts of RAM. You have options of 1GB, 2GB, or 4GB depending on how much you’ll need to do what you want to do. Each tier has its own price ranging from $35 to $55. While there isn’t a crazy big difference in price, you still want to make the right choice. The easy answer that works in all cases is to buy as much as you can afford.

If you plan to use to your Raspberry Pi with a display and interface with it directly beyond the initial setup, buy the 4GB version. There isn’t any independent video memory on a Raspberry Pi, so the total system memory is shared for video. Once the system memory is divided up and reserved for the kernel, modules, the RAMdisk/ZRAM scheme your operating system may use and the video frame buffer, you’re left with a chunk of RAM that is set as unusable for any apps or programs.

You’ll be able to get away with a 2GB version, but not if you plan on using a 4K display. If that’s the case, totally go for the 4GB version – it will be totally worth that extra $20.

If you aren’t planning on attaching a display, you may have no problems using the 1GB version. This depends on what type of services you plan on running. A small and simple project, for example, an LED lighting controller won’t need much RAM at all. Something like a media centre, file/print server or a Wifi access point will benefit from more RAM.

You can do a lot of things with a Pi, ranging from small projects to a complete desktop PC that can play games. Most of them will benefit from extra memory, so buying the 4GB RAM version is always the safest and best bet, but if you have a use case that isn’t going to need to be processing much data and you won’t be attaching a monitor, the 1GB RAM version should work and you can save some money.

What would I do? I’d go for the 4GB version every time. You never know how you might want to re-purpose the Pi, grow the project and things in the future.

Raspberry Pi 3B vs 3B+ Comparison

The Raspberry Pi Foundation has released the Raspberry Pi 3B+, an updated version of the RPi 3B. Its predecessor, the 3B, has now been available on the market for around two years and everyone has been waiting patiently for an updated version.

The 3B+ is the same size as its predecessor. This means that the existing cases and most other accessories can continue to be used without any problems. Much else remains the same and the differences are easily manageable. Most of the changes were in the technical specification.

Technical Differences

3B3B+
Release dateFebruary 2016March 2018
Size85.6 × 56mm85.6 × 56mm
SOCBCM2837BCM2837
CPUARM Cortex-A53
(ARMv8-A)
ARM Cortex-A53
(ARMv8-A)
CPU cores 44
CPU clock speed4 x 1200 MHz4 x 1400 MHz
USB4 x USB 2.04 x USB 2.0
AudioHDMI (digital)
3,5mm jack
HDMI (digital)
3,5mm jack
Network10/100 MBit 10/100/1000 MBit 
WLAN2,4 GHz WLAN b/g/n2,4/5 GHz WLAN ac
BluetoothBluetooth 4.1Bluetooth 4.2
GPIO pins4040
PoENoYes
Maximum power input4.4w7w
Power source5V Micro USB
min. 2.5A
5V Micro USB
min. 2.5A

What’s new in the Raspberry Pi 3B+?

In order of importance (in our opinion):

Faster Network Speeds
In the new LAN7515 chip, Gigabit Ethernet is finally supported. However, you cannot expect the full gigabit data. The reason for this is due to the fact that the gigabit ethernet chip hangs internally on a USB 2.0 controller, so 315 Mbit/s is the maximum. In its predecessor, the Raspberry Pi 3B, the speed was only 95 Mbps. Still a very nice improvement.

Higher CPU Clock Speed
The four ARM cores have also been improved. Now, the clock is set at 1.4 GHz by default, instead of 1.2 GHz and is therefore around 17% faster. A metal lid now serves as a heat spreader to better dissipate the heat produced by the increased clock frequency. There is also a similar metal sheet lid on the GPU. A slight drawback is that the higher clock speed also results in higher power consumption.

5Ghz Wireless
The Broadcom BCM43455 is a new WLAN controller that supports dual-band ac WLAN for 5 GHz wireless, however, only one antenna is installed. For this reason, throughput is only increased moderately.

Power-over-Ethernet
There are now 4 pins for PoE on the board. A PoE HAT for the Raspberry Pi, which can supply the Raspi with up to 12.95 watts (IEEE 802.af). The PoE Hat is now available to purchase here.

Power Consumption & Temperature

Power consumption and running temperatures of the new upgraded model has been the biggest topics, so we decided to run some tests and record our findings.

The setup:

  • Raspberry Pi 3B & 3B+ without case
  • Network via cable to GBit switch
  • OS: Raspbian Stretch Lite
  • Two measurements: Idle and under full load using (“sysbench –test=cpu –cpu-max-prime=25000 –num-threads=8 run“)
  • Room temperature: approx. 21°C
3B3B+
Watt, Idle1.2w2.2w
Watt, Full Load3.7w5.4w
Temperature, Idle43°C39°C
Temperature, Load74°C65°C

Test conclusion:

The RPi 3B+ has a significantly higher power consumption when idling, approximately 80% higher than the 3B. At full load, it is approximately 45% higher than the 3B. However surprisingly, thanks to the new metal heat spreaders, the RPi 3B+ is around 10°C cooler than its previous model. Since the Raspberry Pi throttles the clock rate if the temperature of 85°C is reached, the lower temperature of the 3B+ is a huge positive. This means that the extra power can really be called up without it getting into throttling or requiring noisy and space consuming cooling devices.

The Golden Question – Is it worth upgrading?

Yes and no. It really depends on what the Raspberry Pi in question is being used for. If the focus of the project is on CPU performance, for example a media centre, the 3B+ will perform significantly better. The same applies to high network requirements. If however the project is focused on energy saving and requires only light performance, stick with the 3B.

That being said, if you need a new Pi or are looking to get one for the first time, the sale price of both models are the same, so grab the 3B+!