Browsing the info of my Raspberry PI 4B I found that all the three devices I have, are different. And not just a few differences, but quite substantial, at least according to the info loaded by the kernel. Data:
My older Raspberry PI 4B is a Rev 1.2 with BCM2835 SoC (more info on it later) with 4GB ram but just received (after a long research and wait, due to the chip shortage) another two RPi 4B, one with 2GB ram and the other with 1GB. But here are the curious specs,
the (new) one with 2GB of RAM with BCM2711:
processor : 0
model name : ARMv7 Processor rev 3 (v7l)
BogoMIPS : 126.00
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
processor : 1
model name : ARMv7 Processor rev 3 (v7l)
BogoMIPS : 126.00
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
processor : 2
model name : ARMv7 Processor rev 3 (v7l)
BogoMIPS : 126.00
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
processor : 3
model name : ARMv7 Processor rev 3 (v7l)
BogoMIPS : 126.00
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
Hardware : BCM2711
Revision : b03115
Serial : 10000000xxx
Model : Raspberry Pi 4 Model B Rev 1.5
The (new) one with 1GB of RAM with BCM2835 Rev1.5:
processor : 0
BogoMIPS : 108.00
Features : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
processor : 1
BogoMIPS : 108.00
Features : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
processor : 2
BogoMIPS : 108.00
Features : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
processor : 3
BogoMIPS : 108.00
Features : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
Hardware : BCM2835
Revision : a03115
Serial : 100000000xxx
Model : Raspberry Pi 4 Model B Rev 1.5
And the older with 4GB RAM with BCM2835 Rev1.2:
processor : 0
BogoMIPS : 108.00
Features : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
processor : 1
BogoMIPS : 108.00
Features : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
processor : 2
BogoMIPS : 108.00
Features : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
processor : 3
BogoMIPS : 108.00
Features : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part : 0xd08
CPU revision : 3
Hardware : BCM2835
Revision : c03112
Serial : 10000000xxx
Model : Raspberry Pi 4 Model B Rev 1.2
Searching for some info online, I found that the revision 1.2 should have a better power management and SD card (info), instead the Rev 1.5 should have a better design not only of the PMIC, according to a Raspberry PI dev, and it should run a little less hot:
The PMIC has been changed. Needs firmware from April 21 or later.
Not sure of all the reasons, it’s not just supply, we are constantly improving the design. (link)
On the latest revision, rev1.5, the PMIC should run cooler (link)
FYI: exist also a RPi 4B Rev1.4
About the SoC, the BCM2711 is reported as the SoC of the new RPi 4, CM400, etc… but this shouldn’t be the same in all the PI 4? Yes, and it’s, but due to an error it’s reported wrong by the system, you can simply ignore it and assume that all the RPi 4B have the BCM2711 (also because the BCM2835 is a one core armv7 CPU from the first RPi).
But just to report, I had (and not only me) some troubles with the Rev1.5 and the Pimoroni Hyperpixel display: when I swapped the SD of a Rev1.2 into a Rev1.5 some weird colors appeared on the display, here are the differences with the same microSD, just two different Rev of the board:
top Rev1.2, bottom Rev1.5
Fortunately I solved the issue, here you can read the solution: https://dietpi.com/forum/t/old-sd-on-a-new-rpi-4b-results-in-weird-display-lines/13224/6
If you wonder why I’m using 3 RPi, this is because one is a Pi-Hole server, one is the Homebridge server and the other one is a InfluxDB, Prometheus and Grafana server. I know that I can run all of those things in one, but since the DNS and the lights/air conditioners/etc… are indispensable in my home, I prefer to run them on different devices in case of a failure or a wrong update and whatever reason that can make one process offline and I have to stop all the other if I reboot the one RPi with all the processes on it.
Here’s the setup, I’ll write a longer article in the future about it:
