What are the improvements in Raspberry Pi 4B revision 1.2 and revision 1.4?

[SolitaryDragon]

Due to power supply issues, the Raspberry Pi Foundation released the Rev1.2 update, which solves the problem that some Type-C power cords cannot be powered. When the RPi4B/8GB version was released, the hardware was updated to Rev1.4 version. The 2G/4G model was subsequently released with Rev1.4 version. In the 2G/4G model, what are the differences in circuit structure and function between Rev1.2 and Rev1.4?
This link can only find the version number, and cannot tell me the specific differences.
https://www.raspberrypi.org/documentati ... /README.md
There are very few related materials, only the Rev1.4 version is found in this post, and the EEPROM is deleted in VL805. Is there any function that cannot be realized on Rev1.2?
viewtopic.php?t=275782

[drgeoff]

Apart from the USB-C powering issue there are no functional differences that affect end users between v1.2 and v1.4.

[W. H. Heydt]

The 2G/4G model was subsequently released with Rev1.4 version.

Are you sure about that?

The main difference between v1.2 and v1.4 (for the Pi4B8) is to provide additional power for the larger DRAM chip.

[fruitoftheloom]

The 2G/4G model was subsequently released with Rev1.4 version.

Are you sure about that?

The main difference between v1.2 and v1.4 (for the Pi4B8) is to provide additional power for the larger DRAM chip.

https://www.raspberrypi.org/documentati ... /README.md

[SolitaryDragon]

Apart from the USB-C powering issue there are no functional differences that affect end users between v1.2 and v1.4.

Hey, even if there are no differences that affect the user experience, I still want to know where the differences are? Because the retailer promised to provide me with a 4G version of Rev1.4, and after using it, I found that it was a Rev1.2. I am negotiating with the retailer to resolve this issue

[SolitaryDragon]

The 2G/4G model was subsequently released with Rev1.4 version.

Are you sure about that?

The main difference between v1.2 and v1.4 (for the Pi4B8) is to provide additional power for the larger DRAM chip.

In the 2G/4G model, what is the difference between Rev1.4 and Rev1.2?

[SolitaryDragon]

https://www.raspberrypi.org/documentati ... /README.md

I know this link, but unfortunately, it can not tell me other details except for letting me determine what version of my pi is.

[jamesh]

Quite often a board revision change is because a particular component is cheaper, or because the original component can no longer be purchased. The end result is no difference to the user. Don't get hung up on having the latest board revision. You are not getting more performance. As long as the board works, that is the correct metric to use.

There is a revision where the PCI EEPROM is removed as we moved the code into the firmware EEPROM instead, that reduced component count. Again, made no difference to the end user. That might have been 1.4.

[SolitaryDragon]

Quite often a board revision change is because a particular component is cheaper, or because the original component can no longer be purchased. The end result is no difference to the user. Don't get hung up on having the latest board revision. You are not getting more performance. As long as the board works, that is the correct metric to use.

There is a revision where the PCI EEPROM is removed as we moved the code into the firmware EEPROM instead, that reduced component count. Again, made no difference to the end user. That might have been 1.4.

Thank you for your answer. It's very helpful to me.

I was so concerned about the hardware version because in the Raspberry Pi 2B, when I wanted to boot with USB boot, it was only supported in the Rev1.2 version (there were no 3B or newer models at the time). My device is Rev1.1. Since then I've been paying close attention to hardware versions.

[klricks]

..........
I was so concerned about the hardware version because in the Raspberry Pi 2B, when I wanted to boot with USB boot, it was only supported in the Rev1.2 version (there were no 3B or newer models at the time). My device is Rev1.1. Since then I've been paying close attention to hardware versions.

I always wondered why the 1.2 version of the 2B was not given a new name such as 2B+. At the time it was a source of confusion to have 2 different RPi's with different SOC's and features.... but with the same name (2B).

[DirkS]

Hey, even if there are no differences that affect the user experience, I still want would like to know where the differences are?

FTFY

[cleverca22]

..........
I was so concerned about the hardware version because in the Raspberry Pi 2B, when I wanted to boot with USB boot, it was only supported in the Rev1.2 version (there were no 3B or newer models at the time). My device is Rev1.1. Since then I've been paying close attention to hardware versions.

I always wondered why the 1.2 version of the 2B was not given a new name such as 2B+. At the time it was a source of confusion to have 2 different RPi's with different SOC's and features.... but with the same name (2B).

that special 2B was more of a 3B-, i believe it was just a pi3 without the wifi chip, being sold as a "pi2" board

[W. H. Heydt]

I was so concerned about the hardware version because in the Raspberry Pi 2B, when I wanted to boot with USB boot, it was only supported in the Rev1.2 version (there were no 3B or newer models at the time). My device is Rev1.1. Since then I've been paying close attention to hardware versions.

That is pretty much the only board where the revision number makes any significant different. At least since the flurry of revisions to the Model B, which are irrelevant since the advent of the B+.

Since you mention the Pi2Bv1.2...they are very hard to find at the moment, at least at list price (one major vendor has them, but at $42 rather than $35, and since I want to get 10 to 12 of them, makes a difference). Pi2Bv1.1 boards I can get, but not the v1.2.

[W. H. Heydt]

..........
I was so concerned about the hardware version because in the Raspberry Pi 2B, when I wanted to boot with USB boot, it was only supported in the Rev1.2 version (there were no 3B or newer models at the time). My device is Rev1.1. Since then I've been paying close attention to hardware versions.

I always wondered why the 1.2 version of the 2B was not given a new name such as 2B+. At the time it was a source of confusion to have 2 different RPi's with different SOC's and features.... but with the same name (2B).

that special 2B was more of a 3B-, i believe it was just a pi3 without the wifi chip, being sold as a "pi2" board

Kind of. It also defaults to an underclock of 900MHz, so it runs cooler, as well. I *think* (I don't have a physical example) that they could now be considered a cut down Pi3B+. That is, no WiFi (which is why I like them) and the 900MHz default clock, but with the later chip stepping (which, so far as I know, the Pi3B now has as well). After all...why have two different steppings made? Increases volume on the given part and reduces the number of SoCs that need to be stocked.

Personally...I'd love to see a "Pi2B2v1.4". That is...an underclocked Pi4B without WiFi, even as only a 2GB model. No need to proliferate SKUs in that market segment.

(Anybody have a recent Pi3B or Pi2Bv1.2 in hand to--possibly--confirm the above about SoC stepping?)

[SolitaryDragon]

Since you mention the Pi2Bv1.2...they are very hard to find at the moment, at least at list price (one major vendor has them, but at $42 rather than $35, and since I want to get 10 to 12 of them, makes a difference). Pi2Bv1.1 boards I can get, but not the v1.2.

Maybe it's just that scarcity is more valuable.It's older, but there are fewer of them, and the price is higher.
I checked on my local e-commerce site and the 2B model is about $20 plus or minus $5, but it's not brand new.
I wonder why 900MHz is cooler? Is it because it balances heat and performance?

[bensimmo]

....

I was so concerned about the hardware version because in the Raspberry Pi 2B, when I wanted to boot with USB boot, it was only supported in the Rev1.2 version (there were no 3B or newer models at the time). My device is Rev1.1. Since then I've been paying close attention to hardware versions.

Pi2 v1.2 didn't come out till sometime after the Pi3 was introduced. So, when you got your v1.1 either there was not Pi3 style USB boot.

The v1.4 Pi4 board came out with the 8GB Pi4, so red its blog announcement. It's only recently that the v1.4 board for the other Pi have really been seen as it makes sense to make just one mainboard. Power Circuit, the EEPROM mentioned, [and some SD card 'improvement' (but I forget the details and if it was this model, I could be dreaming too.)]

[ejolson]

....

I was so concerned about the hardware version because in the Raspberry Pi 2B, when I wanted to boot with USB boot, it was only supported in the Rev1.2 version (there were no 3B or newer models at the time). My device is Rev1.1. Since then I've been paying close attention to hardware versions.

Pi2 v1.2 didn't come out till sometime after the Pi3 was introduced. So, when you got your v1.1 either there was not Pi3 style USB boot.

The v1.4 Pi4 board came out with the 8GB Pi4, so red its blog announcement. It's only recently that the v1.4 board for the other Pi have really been seen as it makes sense to make just one mainboard. Power Circuit, the EEPROM mentioned, [and some SD card 'improvement' (but I forget the details and if it was this model, I could be dreaming too.)]

The SD card improvement allows you to multi-boot using a second or third boot partition while the card is in UHS-I mode. There are work arounds in PINN and NOOBS to restrict the card to slower speeds in older versions of the Pi 4B until the final OS is up and running.

[W. H. Heydt]

Since you mention the Pi2Bv1.2...they are very hard to find at the moment, at least at list price (one major vendor has them, but at $42 rather than $35, and since I want to get 10 to 12 of them, makes a difference). Pi2Bv1.1 boards I can get, but not the v1.2.

Maybe it's just that scarcity is more valuable.It's older, but there are fewer of them, and the price is higher.
I checked on my local e-commerce site and the 2B model is about $20 plus or minus $5, but it's not brand new.
I wonder why 900MHz is cooler? Is it because it balances heat and performance?

They are, at least in theory, in current production. My assumption is that the disruptions to supply chains of the past year is the likely reason for spot shortages and when things get back to what passes for normal, that will all get evened out. There are vendor sites that list the Pi2Bv1.2 at list--$35--but also show them as "out of stock". One of those is Okdo.

Another issue is probably competition for manufacturing line time due to the rather large number of new Pi products within the last few months. Note that this excludes the just released Pi Pico, as those are assembled at a Sony plant in Japan. Still...between the Pi400, CM4, and the surge in demand for Pi0s (for ventilator controls) there appears to be a factory crunch. No doubt that Sony Pencoed management is ecstatic with the way the lines are humming, but it's a trifle annoying at this end of the channel.

900MHz is cooler than 1.2GHz because work is heat. Harder you push the electrons around, the more thermal losses there will be. This can be partially offset by making all the parts closer together (using a smaller node), which allows a lower operating voltage which leads to lower power requirement and, thus, less thermal loss.

*Usually* the boost from using a smaller process node is exploited to increase the clock speed within the same thermal envelope (TDP), rather than keeping the clock speed the same and reducing TDP.

[W. H. Heydt]

....

I was so concerned about the hardware version because in the Raspberry Pi 2B, when I wanted to boot with USB boot, it was only supported in the Rev1.2 version (there were no 3B or newer models at the time). My device is Rev1.1. Since then I've been paying close attention to hardware versions.

Pi2 v1.2 didn't come out till sometime after the Pi3 was introduced. So, when you got your v1.1 either there was not Pi3 style USB boot.

Yeah... The Pi2Bv1.1 uses a BCM2836. After the release of the Pi3B, using the BCM2837, the '2836 was dropped from manufacturing and the Pi2Bv1.2 got the '2837, underclocked to match the '2836 clock. If you check the specs carefully, it looks like the v1.2 is probably about 30% faster because of the higher IPC of the Cortex-A53 CPU cores.

The critical difference when it comes to USB MSD booting is that the '2837 has an improved boot ROM on the SoC that permits setting an OTP bit so that it will look for a bootable USB device. The '2836 didn't have that capability.

The other--potentially--interesting difference is that the '2837 can run a 64-bit OS, where the '2836 can't.

If the Pi2Bv1.2 had preceded the Pi3B, it would probably have been considered a significant leap forward, instead of being (to most people) a "ho, hum" completely ignorable afterthought.

However, for anyone who wants a Pi without WiFi that will run with a full peripheral set and stay within a 2A power requirement (which is *very* beneficial for battery powered applications), the Pi2Bv1.2 is a really nice board. If you can get 'em.

[W. H. Heydt]

(Anybody have a recent Pi3B or Pi2Bv1.2 in hand to--possibly--confirm the above about SoC stepping?)

Just got in a new Pi3B. It has the B0 stepping of the BCM2837 (with the metal heat spreader on top). So *that's* confirmed.