Raspberry Pi 4 Thread - general discussion

[andrum99]

I see sdram_freq defaults to 3200!

That's a big improvement from 450 ....

Indeed. That's because the BCM283x uses LPDDR2, while the BCM2711 uses LPDDR4.

[andrum99]

a different Ethernet chip.. ?

This is WiFi - which I believe is the same chip as the Pi3

The Raspberry Pi Foundation and Raspberry Pi Trading are different vendors.

Yes, and I noticed someone (@jamesh maybe) made the point that the Pi4 development is thanks to Raspberry Pi Trading not Raspberry Pi Foundation. Just wondered why...

Originally the Raspberry Pi Foundation was small enough that all of their trading income was below a certain level (which I believe is currently £50,000) so HMRC allowed it to trade but still have all the advantages of being incorporated as a charity. Nowadays the Raspberry Pi income from trading activities far exceeds the £50,000 threshold, so it is much more tax efficient to have the trading done by a wholly owned subsidiary, Raspberry Pi Trading Ltd, which still allows the Raspberry Pi Foundation, the parent company, to enjoy charitable status.

[bunklung]

If I understand correctly the Pi 4 changes the GPU to 600 Mhz when operating in 4K. Why not always operate at 600Mhz?

If 600Mhz is a normal clock operating mode, then what have some of you been able to clock the GPU beyond 600? Tom's Hardware tested at 600 with good results, but again that doesn't seem like really pushing the GPU beyond stock.

[Bakul Shah]

WiFi MAC address changes

My older Pis up to Pi 3B all have MAC addresses B8:27:EB:xx:xx:xx (Raspberry Pi Foundation)
The Pi4 has DC:A6:32:xx:xx:xx (Raspberry Pi Trading)

What's the significance of this change - apart from making the Pi a bit harder to spot in IpScan24?

With the first 3 bytes fixed and last 3 bytes to play with, you get only 16 million unique MAC addresses and they’ve already sold 26 million units! Expect to see more 3 byte (or six hex digit) prefixes for RPF or RPT!

[W. H. Heydt]

WiFi MAC address changes

My older Pis up to Pi 3B all have MAC addresses B8:27:EB:xx:xx:xx (Raspberry Pi Foundation)
The Pi4 has DC:A6:32:xx:xx:xx (Raspberry Pi Trading)

What's the significance of this change - apart from making the Pi a bit harder to spot in IpScan24?

With the first 3 bytes fixed and last 3 bytes to play with, you get only 16 million unique MAC addresses and they’ve already sold 26 million units! Expect to see more 3 byte (or six hex digit) prefixes for RPF or RPT!

Nope. Just expect to see more address collisions. Rare for individuals. More common to large to very large commercial installations. The issue has already come up and been seen "in the wild".

[Bakul Shah]

With the first 3 bytes fixed and last 3 bytes to play with, you get only 16 million unique MAC addresses and they’ve already sold 26 million units! Expect to see more 3 byte (or six hex digit) prefixes for RPF or RPT!

Nope. Just expect to see more address collisions. Rare for individuals. More common to large to very large commercial installations. The issue has already come up and been seen "in the wild".

While it is true that one can not assume unique hardwired MAC addresses, every device on any given IP subnet does need a unique MAC address. Debugging duplicates can be very painful. Device vendors try to minimize address collisions so as to avoid a bad reputation -- may be they'd sell devices with using the same addresses in different parts of the world but not in the same part. I'd expect RPT to be mindful of this.

I did a quick check on IEEE and the top N companies with multiple MAC prefixes are:

Code: Select all

 876 Cisco Systems
 711 Apple
 556 HUAWEI TECHNOLOGIES CO.
 529 Samsung Electronics Co.
 307 ARRIS Group
 268 Intel Corporate
 197 Texas Instruments
 175 IEEE Registration Authority
 171 zte corporation
 150 Hewlett Packard

This was using a dumb one line shell script (see below). If the same vendor has slightly different entries, they will be counted as different vendors.

Code: Select all

wget http://standards-oui.ieee.org/oui/oui.csv
cut -d, -f 3 oui.csv| sed 's/"//g'|sort|uniq -c|sort -nr|head -10

[jamesh]

If I understand correctly the Pi 4 changes the GPU to 600 Mhz when operating in 4K. Why not always operate at 600Mhz?

If 600Mhz is a normal clock operating mode, then what have some of you been able to clock the GPU beyond 600? Tom's Hardware tested at 600 with good results, but again that doesn't seem like really pushing the GPU beyond stock.

Make little difference to speed, but a big difference to the SoC temperature. So unless you need it, we disable it to keep temperatures down.

[joan]

Has there been any indication as to when the BCM2711 Peripherals Specification will be released, or more specifically the memory addresses of the GPIO registers to be access via C/C++?

Haven't found anything myself, but screen reading sometimes misses things.

Cheers!

On the Pi4B the peripheral base address appears to be 0xfe000000 from Linux. The offsets to the various peripherals from that base address appear to be unchanged.

[solar3000]

I was a little confused about the two mini HDMI ports vs one full size one,

FYI they are micro HDMI not mini HDMI.
PeterO

That's nothing. Someone in a previous post said HTML port.

[solar3000]

So I plugged in a Samsung phone charger that supplies 5.12 volts at 2 amps........so far, no dreaded low voltage lightning bolt.
So far, I have the pi running youtube videos on a web browser, the current drain has ranged from .6A to .9A.

[solar3000]

How much GPU should I set?
I'm thinking of running youtube videos and general web browsing, videos, etc...

[solar3000]

So can I use a bluetooth headset with the pi? Would the mic work?

[geri12]

I wonder if the pin muxing isn't right.
Please check with "raspi-gpio get" that GPIOs 0-27 are all set to alt2 for the DPI function.
You can achieve the same as "dtoverlay=dpi24" by doing "gpio=0-27=a2".

Yay! That did it! The screen didn't look quite right with that dpi_timing line, but it turns out that old hdmi_cvt line still works with the correct gpio settings in place. Thank you!

Hi!

DPI display Works PI4:

Update Raspbian Jessie on pi3. (where the display is already set and works …)

1. In the files /etc/apt/sources.list and /etc/apt/sources.list.d/raspi.list, change every use of the word “stretch” to “buster”.
2. In a terminal, sudo apt update and then sudo apt dist-upgrade
3. Wait for the upgrade to complete, answering ‘yes’ to any prompt. There may also be a point at which the install pauses while a page of information is shown on the screen – hold the ‘space’ key to scroll through all of this and then hit ‘q’ to continue.
4. The update will take anywhere from half an hour to several hours, depending on your network speed. When it completes, reboot your Raspberry Pi...

5. Reboot
6. If all is well, then shut down pi3. SD card transfer to pi4. It will start Raspbian buster, and the display perfect, not dark.

[MrMcTiller]

I'm sorry if someone already asked this, but would the Pi 4 support dual 1440x900 @ 60fps?

Also, does anyone know of any cases that support having a fan for the rpi4? This little Pi runs a bit toasty.

And one more thing, I've seen little fans that you can tape to the top of the heatsinks on Pi boards. Anyone know where to get those and the heatsinks?

[dom]

Also, does anyone know of any cases that support having a fan for the rpi4? This little Pi runs a bit toasty.

And one more thing, I've seen little fans that you can tape to the top of the heatsinks on Pi boards. Anyone know where to get those and the heatsinks?

Assuming the FLIRC case for Pi4 works like previous ones that is a good choice. It typically lowers temperatures by about 30'C without a fan (the whole case is an aluminium heat sink). See: https://kodi.tv/article/flirc-kodi-edit ... pi-4b-case
(not available yet, but can preorder).

[jahboater]

This little Pi runs a bit toasty.

Try the command "vcgencmd get_throttled" after running a typical workload.
If it says 0x0 (zero) you have nothing to worry about temperature wise.

Outside of a case its unlikely to throttle, even without a heat sink.
Unless perhaps you live in the tropics - or central Europe

[W. H. Heydt]

Outside of a case its unlikely to throttle, even without a heat sink.
Unless perhaps you live in the tropics - or central Europe

Where I live, about 30 miles NE of San Francisco, CA, we get days where it runs over 100F and this area is hardly described as "tropics". There are places I've been NE about 150 miles of where I live that have hit over 120F in the summer.

One is reminded of the (possibly apocryphal) headline from the Times of London: 80 degrees again today, no relief in sight. Goes well with the other supposed headline...Fog over the channel. Europe cut off.

[mkirk]

What WiFi/BLE chipset is used on the new Pi 4B?
I am guessing a Cypress (Broadcom) part, but does anyone know the part number?

Will is support simultaneous AP + STA (client) mode like the CYW43438 on the Pi 3B?

We have one on backorder, so when it arrives with can query iw list to check ourselves.

[gtechn]

Not quite related to the previous discussion, but for the Engineers:

I've been watching many of the Pi 4 review videos (and I'm sure you have too), and I've noticed that many (at least in my recommendations, almost all) of the reviewers are opening up Chromium and trying to play even 1080p and complaining that it still can't play 4K video. Of course, I know this is ridiculous because this version of Chromium even has the GPU specially disabled, but the reviewers don't seem to know that.

My point is, when the GPU is re-enabled on Chromium, it might be worth publishing an official blog post on the RPi website not only describing why the GPU was disabled in Chromium, that performance is better know, but also how to effectively access the GPU (i.e. use LibreElec). Misunderstandings about how the GPU is used and how it "isn't that much of an improvement for video - look at YouTube!" are everywhere.

What WiFi/BLE chipset is used on the new Pi 4B?

The WiFi chipset has not been changed in any way. The Bluetooth 5.0 / 5GHz broadband was a firmware update, but the chipset itself remains the same.

[Heater]

W. H. Heydt,

One is reminded of the (possibly apocryphal) headline from the Times of London: 80 degrees again today, no relief in sight.

Apocryphal or not. 80F is only 26.7C.

It has been over that temperature everyday for a week or more my apartment, with all the doors and windows open. I'm in Finland!

Did you not see the news today of record temperatures in France, Germany and Spain?

The Pi is going to need all the cooling it can get as we push climate change over the edge!

[mkirk]

This does not make sense, the Pi 3B has CYW43438 chip that does not support 5 GHz WiFi

But 4B does support 5 GHz WiFi, so is is not the CYW43438 chip.

Did you mean to say the 4B uses the same chipset as the Pi 3B+ (not 3B)?
https://www.cypress.com/file/358916/download CYW43455

[gtechn]

I was referring to the previous generation of Raspberry Pi, which is the 3B+.

[EdwinJ85]

I was a little confused about the two mini HDMI ports vs one full size one,

FYI they are micro HDMI not mini HDMI.
PeterO

That's nothing. Someone in a previous post said HTML port.

Oh dear. I'm never living this one down am I?

[alphanumeric]

FYI they are micro HDMI not mini HDMI.
PeterO

That's nothing. Someone in a previous post said HTML port.

Oh dear. I'm never living this one down am I?

Blame it on autocorrect and your off the hook.

[MrMcTiller]

Also, does anyone know of any cases that support having a fan for the rpi4? This little Pi runs a bit toasty.

And one more thing, I've seen little fans that you can tape to the top of the heatsinks on Pi boards. Anyone know where to get those and the heatsinks?

Assuming the FLIRC case for Pi4 works like previous ones that is a good choice. It typically lowers temperatures by about 30'C without a fan (the whole case is an aluminium heat sink). See: https://kodi.tv/article/flirc-kodi-edit ... pi-4b-case
(not available yet, but can preorder).

Thank you for that.

So... any idea on the dual 1440x900 @ 60FPS?