M1S vu5s and vu8s + HDMI limitations

Post Reply
User avatar
mad_ady
Posts: 11755
Joined: Wed Jul 15, 2015 5:00 pm
languages_spoken: english
ODROIDs: XU4 (HC1, HC2), C1+, C2, C4 (HC4), N1, N2, N2L, H2, H3+, Go, Go Advance, M1, M1S
Location: Bucharest, Romania
Has thanked: 656 times
Been thanked: 1197 times
Contact:

M1S vu5s and vu8s + HDMI limitations

Post by mad_ady »

Hello,
I've looked over the wiki pages for the vu5s and vu8s:

https://wiki.odroid.com/odroid-m1s/appl ... _note/vu5s
https://wiki.odroid.com/odroid-m1s/appl ... _note/vu8s

and for vu8s it says:
If you activate the MIPI-DSI interface, the HDMI output function will be disabled automatically.
This is because HDMI and MIPI-DSI can NOT be used simultaneously due to system memory bandwidth limitations.
But the same warning is not present on the vu5s page. Is the same limitation present with vu5s and do you need to add the warning that the platform can't do dual displays (like M1), or would the vu5s work together with a HDMI display?
What about using a lower resolution with HDMI (e.g. connecting a VU7 via HDMI) - is the memory bandwidth limitation present at lower resolutions as well?

Thanks for the clarification!
Cheers!

User avatar
odroid
Site Admin
Posts: 41864
Joined: Fri Feb 22, 2013 11:14 pm
languages_spoken: English, Korean
ODROIDs: ODROID
Has thanked: 3433 times
Been thanked: 1920 times
Contact:

Re: M1S vu5s and vu8s + HDMI limitations

Post by odroid »

Vu5S wiki page is still under construction. :oops: :
I've just added the same warning message to the Vu5S wiki page. ;)

1920x1080 HDMI + 1280x800 MIPI-DSI couldn't work together in parallel on the M1S while the original M1 could use dual displays thanks to the faster DRAM bandwidth.
We may need to test more, for example, if 1024x600 HDMI + 1280x800 MIPI-DSI can work together or not.

My guess is that dual displays may be possible with a low resolution combination, but it is unlikely to be suitable for use in actual applications due to insufficient CPU/GPU performance.

User avatar
mad_ady
Posts: 11755
Joined: Wed Jul 15, 2015 5:00 pm
languages_spoken: english
ODROIDs: XU4 (HC1, HC2), C1+, C2, C4 (HC4), N1, N2, N2L, H2, H3+, Go, Go Advance, M1, M1S
Location: Bucharest, Romania
Has thanked: 656 times
Been thanked: 1197 times
Contact:

Re: M1S vu5s and vu8s + HDMI limitations

Post by mad_ady »

Thanks for the clarification.
So - if both displays were to remain enabled (somehow), what should an end user expect? Screen tearing? Would it affect application performance because RAM bandwidth would be saturated?
My use-case for 2 displays involves mostly static images, so screen tearing would be acceptable. The HDMI display would display photos, the vu5s would display a browser dashboard. Right now, the 10 fps I get from the 3.5" display is plenty :)

User avatar
tobetter
Posts: 12610
Joined: Mon Feb 25, 2013 10:55 am
languages_spoken: Korean, English
ODROIDs: Many
Location: Paju, South Korea
Has thanked: 938 times
Been thanked: 2162 times
Contact:

Re: M1S vu5s and vu8s + HDMI limitations

Post by tobetter »

mad_ady wrote:
Wed Nov 15, 2023 8:01 pm
Thanks for the clarification.
So - if both displays were to remain enabled (somehow), what should an end user expect? Screen tearing? Would it affect application performance because RAM bandwidth would be saturated?
My use-case for 2 displays involves mostly static images, so screen tearing would be acceptable. The HDMI display would display photos, the vu5s would display a browser dashboard. Right now, the 10 fps I get from the 3.5" display is plenty :)
As of now, it's more than tearing...plenty random picture tiles on the screen.

User avatar
mctom
Posts: 3528
Joined: Wed Nov 11, 2020 4:44 am
languages_spoken: english, polski
ODROIDs: XU4, M1, H3+, SP3, N2L, M1S
Location: Gdańsk, Poland
Has thanked: 499 times
Been thanked: 674 times
Contact:

Re: M1S vu5s and vu8s + HDMI limitations

Post by mctom »

The RK3566 datasheet does say...
Support two simultaneous displays(same source) in the following interfaces:
Maybe would have worked fine if they were displaying the same thing.
Punk ain't no religious cult, punk means thinking for yourself!
OpenUPS
PiStackMon

User avatar
mad_ady
Posts: 11755
Joined: Wed Jul 15, 2015 5:00 pm
languages_spoken: english
ODROIDs: XU4 (HC1, HC2), C1+, C2, C4 (HC4), N1, N2, N2L, H2, H3+, Go, Go Advance, M1, M1S
Location: Bucharest, Romania
Has thanked: 656 times
Been thanked: 1197 times
Contact:

Re: M1S vu5s and vu8s + HDMI limitations

Post by mad_ady »

Ah, that might hamper my original plans... Thanks!

Post Reply

Return to “Hardware and peripherals”

Who is online

Users browsing this forum: No registered users and 1 guest