W. H. Heydt
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Re: About the New Raspberry Pi 4b cpu revision

Mon Oct 11, 2021 6:42 pm

jamesh wrote:
Mon Oct 11, 2021 10:01 am
I don't think there is a new version of the 2837 (but really, it doesn''t matter anyway, these stepping changes are irrelevant to most users), and since the difference to the 2711 are huge, I doubt it will be getting that on the Pi3!
I think the last change to the 2837 was to flip it over (and mirror image it so the connections came out the same) and package it with a heat spreader. Since it was before that that the Pi2B went from v1.1 with a 2836 to v1.2 with a 2837 I'm expecting--some day--for the flipped 2837 with heat spreader to show up on the Pi2Bv1.2.

And, as you implied by omission, the 2836 and 2837 were far, far more similar than either is to the 2711.

AmirulAndalib
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Re: About the New Raspberry Pi 4b cpu revision

Tue Oct 12, 2021 3:16 am

andrum99 wrote:
Mon Oct 11, 2021 4:38 pm
To me the thermals are not the most important change on the new stepping - I believe the reason there is a C0 stepping to start with is because of a layout bug in the B0 which limits the PCIe controller to only being able to address the first 3GB of RAM. The PCIe controller on the BCM2711 also has other limitations, but is perfectly adequate for it's intended use, unless you're trying to run an external GPU or some other extreme use case.
yes this change is seen on the new cpu revision i wanted to attach my Gt710 to this pi4 b :D

ejolson
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Re: About the New Raspberry Pi 4b cpu revision

Tue Oct 12, 2021 3:40 am

AmirulAndalib wrote:
Tue Oct 12, 2021 3:16 am
andrum99 wrote:
Mon Oct 11, 2021 4:38 pm
To me the thermals are not the most important change on the new stepping - I believe the reason there is a C0 stepping to start with is because of a layout bug in the B0 which limits the PCIe controller to only being able to address the first 3GB of RAM. The PCIe controller on the BCM2711 also has other limitations, but is perfectly adequate for it's intended use, unless you're trying to run an external GPU or some other extreme use case.
yes this change is seen on the new cpu revision i wanted to attach my Gt710 to this pi4 b :D
While the emoticon likely indicates you are saying this as a joke, for others who may not know, my understanding is that no NVIDIA GPU driver has ever been made to work with the with the BCM2711 whether C0 stepping or not. I don't think AMD graphics cards fair any better.

AmirulAndalib
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Re: About the New Raspberry Pi 4b cpu revision

Tue Oct 12, 2021 3:54 am

ejolson wrote:
Tue Oct 12, 2021 3:40 am
AmirulAndalib wrote:
Tue Oct 12, 2021 3:16 am
andrum99 wrote:
Mon Oct 11, 2021 4:38 pm
To me the thermals are not the most important change on the new stepping - I believe the reason there is a C0 stepping to start with is because of a layout bug in the B0 which limits the PCIe controller to only being able to address the first 3GB of RAM. The PCIe controller on the BCM2711 also has other limitations, but is perfectly adequate for it's intended use, unless you're trying to run an external GPU or some other extreme use case.
yes this change is seen on the new cpu revision i wanted to attach my Gt710 to this pi4 b :D
While the emoticon likely indicates you are saying this as a joke, for others who may not know, my understanding is that no NVIDIA GPU driver has ever been made to work with the with the BCM2711 whether C0 stepping or not. I don't think AMD graphics cards fair any better.
not a joke i saw tutorial videos on Youtube on how to install nvidia gpu in raspberry pi4 So i decided to give it a try :?

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Gavinmc42
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Re: About the New Raspberry Pi 4b cpu revision

Tue Oct 12, 2021 6:02 am

not a joke i saw tutorial videos on Youtube on how to install nvidia gpu in raspberry pi4 So i decided to give it a try
Look at the Jeff Geerling YT ch, he is using CM4 with CM4 I/O board not a Pi4.
He is getting close but I don't he has done it yet?
https://pipci.jeffgeerling.com/

You need access to the PCIe pins on the BCM2711.
On a P4B those go to the PCIe USB2/3 hub chip which is not on the CM4.
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jamesh
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Re: About the New Raspberry Pi 4b cpu revision

Tue Oct 12, 2021 8:51 am

AmirulAndalib wrote:
Tue Oct 12, 2021 3:54 am
ejolson wrote:
Tue Oct 12, 2021 3:40 am
AmirulAndalib wrote:
Tue Oct 12, 2021 3:16 am


yes this change is seen on the new cpu revision i wanted to attach my Gt710 to this pi4 b :D
While the emoticon likely indicates you are saying this as a joke, for others who may not know, my understanding is that no NVIDIA GPU driver has ever been made to work with the with the BCM2711 whether C0 stepping or not. I don't think AMD graphics cards fair any better.
not a joke i saw tutorial videos on Youtube on how to install nvidia gpu in raspberry pi4 So i decided to give it a try :?
This would require a lot of cutting up of the board and soldering. Much easier to use a CM4 and IO board where the PCI is exposed. CM4's use the C0.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Working in the Applications Team.

AmirulAndalib
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Re: About the New Raspberry Pi 4b cpu revision

Tue Oct 12, 2021 1:23 pm

jamesh wrote:
Tue Oct 12, 2021 8:51 am
AmirulAndalib wrote:
Tue Oct 12, 2021 3:54 am
ejolson wrote:
Tue Oct 12, 2021 3:40 am

While the emoticon likely indicates you are saying this as a joke, for others who may not know, my understanding is that no NVIDIA GPU driver has ever been made to work with the with the BCM2711 whether C0 stepping or not. I don't think AMD graphics cards fair any better.
not a joke i saw tutorial videos on Youtube on how to install nvidia gpu in raspberry pi4 So i decided to give it a try :?
This would require a lot of cutting up of the board and soldering. Much easier to use a CM4 and IO board where the PCI is exposed. CM4's use the C0.
mmm yes good idea

AmirulAndalib
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Re: About the New Raspberry Pi 4b cpu revision

Tue Oct 12, 2021 1:23 pm

AmirulAndalib wrote:
Tue Oct 12, 2021 1:23 pm
jamesh wrote:
Tue Oct 12, 2021 8:51 am
AmirulAndalib wrote:
Tue Oct 12, 2021 3:54 am


not a joke i saw tutorial videos on Youtube on how to install nvidia gpu in raspberry pi4 So i decided to give it a try :?
This would require a lot of cutting up of the board and soldering. Much easier to use a CM4 and IO board where the PCI is exposed. CM4's use the C0.
mmm yes good idea
also i am gonna use low end gpu like 750ti or less

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geerlingguy
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Re: About the New Raspberry Pi 4b cpu revision

Tue Oct 12, 2021 11:32 pm

AmirulAndalib wrote:
Tue Oct 12, 2021 1:23 pm
AmirulAndalib wrote:
Tue Oct 12, 2021 1:23 pm
jamesh wrote:
Tue Oct 12, 2021 8:51 am


This would require a lot of cutting up of the board and soldering. Much easier to use a CM4 and IO board where the PCI is exposed. CM4's use the C0.
mmm yes good idea
also i am gonna use low end gpu like 750ti or less
FYI I've been testing a number of different cards—my results are all posted on my tracking site: https://pipci.jeffgeerling.com/#gpus-graphics-cards

Right now the major issue is all drivers assume cache coherence on 64-bit Pi OS, and most drivers don't work in other weird ways on 32-bit Pi OS (I don't think many driver devs even support 32-bit anymore...).

And before you ask about running Windows 11 on ARM—that doesn't help :)
The question is not whether something should be done on a Raspberry Pi, it is whether it can be done on a Raspberry Pi.

cleverca22
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Re: About the New Raspberry Pi 4b cpu revision

Tue Oct 12, 2021 11:36 pm

geerlingguy wrote:
Tue Oct 12, 2021 11:32 pm
And before you ask about running Windows 11 on ARM—that doesn't help
yeah, then you have the problem of drivers assuming coherency, and being closed source, so you cant even fix the driver!

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Gavinmc42
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Re: About the New Raspberry Pi 4b cpu revision

Wed Oct 13, 2021 1:46 am

yeah, then you have the problem of drivers assuming coherency, and being closed source, so you cant even fix the driver!
How much is closed?
https://nouveau.freedesktop.org/

For AMD this looks interesting.
https://gpuopen.com/amd-open-source-driver-for-vulkan/
Once the BCM2711/VC6 has Vulkan 1.2 drivers will it be easier?

Lucky the CM4 already has the C0, the small changes do make a difference for even attempting these PCIe things.
Will it mean much to the Pi4B < 4GB?
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Raspberries are not Apples or Oranges

AmirulAndalib
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Re: About the New Raspberry Pi 4b cpu revision

Mon Oct 18, 2021 2:24 pm

Gavinmc42 wrote:
Wed Oct 13, 2021 1:46 am
yeah, then you have the problem of drivers assuming coherency, and being closed source, so you cant even fix the driver!
How much is closed?
https://nouveau.freedesktop.org/

For AMD this looks interesting.
https://gpuopen.com/amd-open-source-driver-for-vulkan/
Once the BCM2711/VC6 has Vulkan 1.2 drivers will it be easier?

Lucky the CM4 already has the C0, the small changes do make a difference for even attempting these PCIe things.
Will it mean much to the Pi4B < 4GB?
sadly i dont see any CM4 module on amazon and the one I am seeing have very less reviews like abut 10-12 and with 1-3 stars :/

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Gavinmc42
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Re: About the New Raspberry Pi 4b cpu revision

Tue Oct 19, 2021 12:32 am

sadly i dont see any CM4 module on amazon and the one I am seeing have very less reviews like abut 10-12 and with 1-3 stars :/
CM4 is not a beginners Pi and I never buy serious electronics from Amazon.
Plenty of specialist Pi suppliers around depending on your country.
Those specialist companies actually use Pi's so know them better than Amazon.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

ahecht
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Re: About the New Raspberry Pi 4b cpu revision

Tue Nov 09, 2021 2:47 am

jamesh wrote:
Sun Oct 10, 2021 1:17 pm
AmirulAndalib wrote:
Sun Oct 10, 2021 12:17 pm
jamesh wrote:
Sun Oct 10, 2021 12:09 pm
Hi, yes, the C0 stepping will make it to other models over time, but you won't be able to buy a specific model. TBH, you won't notice any real difference between them anyway, so not really any point in trying to find the C0.
but i had seen there had been some cpu speed improvements as It can overclock without the thermals...Also the stock speed of the newer ones is 1.8-ghz while the older ones are 1.5-ghz
Stock speed remains the same on the Pi4. The changes inside the SoC give a slight improvement in power gating, but not a huge amount. So overclocked might be very slightly cooler, but not by very much, depends totally on the workload. Not worth the effort in trying to find a C0.
If that's true, why does Bullseye run the C0 chips 300Mhz faster than the B0 chips by default?

ejolson
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Re: About the New Raspberry Pi 4b cpu revision

Tue Nov 09, 2021 3:19 am

ahecht wrote:
Tue Nov 09, 2021 2:47 am
jamesh wrote:
Sun Oct 10, 2021 1:17 pm
AmirulAndalib wrote:
Sun Oct 10, 2021 12:17 pm


but i had seen there had been some cpu speed improvements as It can overclock without the thermals...Also the stock speed of the newer ones is 1.8-ghz while the older ones are 1.5-ghz
Stock speed remains the same on the Pi4. The changes inside the SoC give a slight improvement in power gating, but not a huge amount. So overclocked might be very slightly cooler, but not by very much, depends totally on the workload. Not worth the effort in trying to find a C0.
If that's true, why does Bullseye run the C0 chips 300Mhz faster than the B0 chips by default?
Obviously the stock speeds are no longer the same with the new operating system.

If the president of the United States can claim to not know his adminstration was preparing to pay 450K to families who illegally entered the country, surely it's possible an engineer might not know his company was preparing to increase the stock speeds of the C0 by 300 MHz.

At any rate unexpectedly increasing the performance by 20 percent is much better than decreasing it, as happened with many x86 systems to mitigate the Meltdown security bug a few years ago.

scaramonga
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Re: About the New Raspberry Pi 4b cpu revision

Tue Nov 09, 2021 3:54 am

Welp! My Pi is suddenly useless now, as it's clocked 300Mhz lower @ default, lol :lol:

trejan
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Re: About the New Raspberry Pi 4b cpu revision

Tue Nov 09, 2021 4:05 am

ahecht wrote:
Tue Nov 09, 2021 2:47 am
If that's true, why does Bullseye run the C0 chips 300Mhz faster than the B0 chips by default?
It doesn't require a C0 stepping SoC. The requirement is a Pi 4B v1.4 with any SoC stepping.

ejolson
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Re: About the New Raspberry Pi 4b cpu revision

Tue Nov 09, 2021 5:19 am

trejan wrote:
Tue Nov 09, 2021 4:05 am
ahecht wrote:
Tue Nov 09, 2021 2:47 am
If that's true, why does Bullseye run the C0 chips 300Mhz faster than the B0 chips by default?
It doesn't require a C0 stepping SoC. The requirement is a Pi 4B v1.4 with any SoC stepping.
Thanks for the correction. Does that mean this change has more to do with the PMIC than the stepping?

trejan
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Re: About the New Raspberry Pi 4b cpu revision

Tue Nov 09, 2021 5:37 am

ejolson wrote:
Tue Nov 09, 2021 5:19 am
Does that mean this change has more to do with the PMIC than the stepping?
Yes. It appears the upgraded secondary PMIC is the actual requirement. My Pi 4B 8GB v1.4 with B0 stepping now runs at 1.8GHz with the stock Bullseye config.txt.

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RasPiGaming
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Re: About the New Raspberry Pi 4b cpu revision

Tue Nov 09, 2021 2:23 pm

The new 1.8Ghz speed is nothing for me though, because I've already overclocked to 1.8Ghz! :lol:
An RPi can be a gaming PC. As long as you have the right packages and software anyway.
Using a RPi4 8GB with Ubuntu Desktop 21.04, main interests are gaming and programming. Also occasionally uses two RPi3B+ and a RPi3B.

jamesh
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Re: About the New Raspberry Pi 4b cpu revision

Tue Nov 09, 2021 3:27 pm

trejan wrote:
Tue Nov 09, 2021 5:37 am
ejolson wrote:
Tue Nov 09, 2021 5:19 am
Does that mean this change has more to do with the PMIC than the stepping?
Yes. It appears the upgraded secondary PMIC is the actual requirement. My Pi 4B 8GB v1.4 with B0 stepping now runs at 1.8GHz with the stock Bullseye config.txt.
This. Unrelated to the stepping of the device, everything to do with the PMIC.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Working in the Applications Team.

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geerlingguy
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Re: About the New Raspberry Pi 4b cpu revision

Tue Nov 09, 2021 3:35 pm

And to add more clarity; today's blog post details how to identify a revision 1.4 Pi 4 board (apparently some even have B0 chips on them!): https://www.raspberrypi.com/news/bullse ... erry-pi-4/

My speculation in yesterday's video that the bit that mattered was the chip stepping was incorrect. My own testing (with the boards I had on hand) backed up the theory, but I quickly found out that people were having B0 boards with the boost, and C0 Compute Modules that didn't get it by default.

So it seems that the venn diagram of C0 chips to Pis which will get a little speed boost with arm_boost and rev 1.4 boards is not quite identical.
The question is not whether something should be done on a Raspberry Pi, it is whether it can be done on a Raspberry Pi.

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AkulaMD
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Re: About the New Raspberry Pi 4b cpu revision

Tue Nov 09, 2021 3:54 pm

ejolson wrote:
Tue Nov 09, 2021 3:19 am
ahecht wrote:
Tue Nov 09, 2021 2:47 am
jamesh wrote:
Sun Oct 10, 2021 1:17 pm


Stock speed remains the same on the Pi4. The changes inside the SoC give a slight improvement in power gating, but not a huge amount. So overclocked might be very slightly cooler, but not by very much, depends totally on the workload. Not worth the effort in trying to find a C0.
If that's true, why does Bullseye run the C0 chips 300Mhz faster than the B0 chips by default?
Obviously the stock speeds are no longer the same with the new operating system.

If the president of the United States can claim to not know his adminstration was preparing to pay 450K to families who illegally entered the country, surely it's possible an engineer might not know his company was preparing to increase the stock speeds of the C0 by 300 MHz.

At any rate unexpectedly increasing the performance by 20 percent is much better than decreasing it, as happened with many x86 systems to mitigate the Meltdown security bug a few years ago.
Actually it's not so much about the C0 stepping. As long as your board is version 1.4, you are good to go. My Pi 4B 8GB with B0 stepping get the 1.8 GHz free upgrade.
Raspberry Pi OS (32-bit) with desktop and recommended software
Raspberry Pi 4 Model B 8GB at stock speed (never overclock)

Never overclock your Pi.
Encourage optimization instead.

andrum99
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Re: About the New Raspberry Pi 4b cpu revision

Tue Nov 09, 2021 4:43 pm

trejan wrote:
Tue Nov 09, 2021 5:37 am
ejolson wrote:
Tue Nov 09, 2021 5:19 am
Does that mean this change has more to do with the PMIC than the stepping?
Yes. It appears the upgraded secondary PMIC is the actual requirement. My Pi 4B 8GB v1.4 with B0 stepping now runs at 1.8GHz with the stock Bullseye config.txt.
Correct - it's the board being rev 1.4 or higher that is what gets you the higher clock speed by default. From memory, there a sub-PMIC on the rev 1.4 board (a DS something-or-other) that isn't on previous board revisions. Some rev 1.4 boards have a SoC with the B0 stepping, some have the C0 stepping, but all rev 1.4 boards will default to 1.8GHz with the 'arm_boost=1' setting in config.txt.

mcury
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Re: About the New Raspberry Pi 4b cpu revision

Sun Nov 21, 2021 9:01 pm

Hm, mine won't get the boost to 1.8.. But no problem, it's still my baby :)

Hardware : BCM2835
Revision : c03112
Serial :
Model : Raspberry Pi 4 Model B Rev 1.2

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