Raspbery PI4 4GB model no video output above 640mb in config.txt

thor2189 · October 15, 2020 at 1:42 AM

hello all, just got my new 4gb Raspberry PI4 in to day. loaded it up with Libreelec 9.2.5 and all updates. i then started playing around with the config.txt file as i have a notes from setting up my Raspberry PI3. the issue is when i adjust the GPU ram past 640MB the video output cuts out after reboot, just a black screen the TV knows somethings there but its just a black screen. i will see the Raspberry PI splash then nothing. i can still ssh into the pi, configure and reboot as need. i did try and kill -9 the kodi.bin to see if it was just a crash at boot but no luck. not sure if its a bug or if anyone else has had the same issue. i did started at 512MB and walked it up by 128MB each time, 640MB works however, 768MB+ will produce the no video output issue.

let me know if anyone else has this issue kind of curious on it.

Raspberry PI4 4GB model

CPU - Broadcom BCM2711B0 quad-core A72 (ARMv8-A) 64-bit @ 1.5GHz.

GPU - Broadcom VideoCore VI

**Klojum** · October 15, 2020 at 1:49 AM Official Post

Setting the GPU memory to 320 MB is the option most used by RPI4 users.

I see no reason why doubling that amount would still be beneficial.

thor2189 · October 15, 2020 at 2:27 AM

i just really wanted to give the pi 3gb of vram. just wanted to see what it could do.

stack · October 19, 2020 at 2:48 AM

The official docs for a long time basically said "Don't go over 512MB; there be dragons and boot problems over yonder. Plus, there's little benefit."
Not sure when it changed, but there is now a 1GB max memory recommendation for the RPi4.

I played with a bunch of config options and I scrape metrics every 10 seconds so I can compare videos against various tweaking. It's pretty rare that the videos I throw at it are ever more than 100MB of used GPU memory.

I've not found a reason for why going over 320MB would be beneficial, but as long as you are greater than 128MB you should be fine.

Hope that helps.

Edit: Hrmmm.... I just noticed that the official docs now recommend not going over 256 on the RPi4 because of how the RPi4 handles memory. Hrm. I might need to do some testing.
Memory options in config.txt - Raspberry Pi Documentation

thor2189 · October 24, 2020 at 3:45 AM

stack

yes that was very helpful... not sure if i will keep my RP4 on libreelec machine and kick it back to my RP3 as it did just fine and i could use the RP4 for new projects in the works. but the native x265 support is nice