LE 8 and RX 550

Hi,

Having read about future of Kodi and LibreELEC and how bad nVidia is in that respect (no further VDPAU development hence there will not be HEVC 10 bit decoding, no proper DRMPRIME support/no Waytand etc etc), I decided to buy low profile (my HTPC case is low profile) Radeon RX 550 4GB and give it a try under latest LE 8. So far I was using GTX 1050 Ti.

Two major issues with RX 550:

- no matter what I do, for 4K resolution I can only select 30Hz refresh. Under Windows on the same HW 60Hz is no problem (whole system is fully HDMI 2.0 capable). I read about enforcing resultuions with xrandr but all I can achieve is black screen at most.

- with VAAPI enabled, everything is played back as SW decoding, even FHD movies.

RX 550 is not that new, I thought it should be fully supported under LE 8. Maybe I should give LE 9 alpha a try ?

So I updated to latest LE 9 alpha.

VAAPI is now working fine, even 10 bit HEVC is hardware-decoded on RX 550. But sound passthrough via HDMI is not stable, there are audio dropouts.

And I still cannot get 4K/60Hz to work, for 4K 30Hz is the maximum available option. 60Hz only for FHD.

Moreover I see no option to adjust black levels anywhere (I had this option available with 1050Ti) so picture is too bright. With LibreELEC booted respective "HDMI black level" option in my Samsung TV is locked to 'stanard' level.

With Windows booted, I can change pixel format in Radeon Settings to various settings but only if I'm at 4K/30Hz. Black level option in my TV is then unlocked to "standard" or "low".

If I'm at 4K/60Hz in Windows then the only possible setting is YCbCr 4:2:0 (if I recall correctly) and then TV is locked to "standard" black level (like in LE 9). I'm suspecting then that LE 9 is using pixel format that cannot support 4K/60Hz on RX 550.

I had no such issues with 1050Ti - I could run 4K at 60HZ (both Windows and LE) and I had black level option available in Kodi.

I coludn't get RX 550 to work properly even under latest LE 9 Millhouse build.

Audio dropouts, incorrect black level, 4K locked to 30Hz. Even under windows it's not as good for multimedia as GTX 1050.

Decided to return RX 550.

No idea what is the best and future proof GPU for LE then. nVidia lacking required APIs, only VDPAU which is dead. AMD buggy beyond acceptable level.

Maybe just integrated Intel ? Buch which Intel CPU supports HDMI 2.0 ?

Indeed. I just removed nVidia 1050Ti and switched to Intel HD 610 built into G4560. This does work well both under Windows and LE (via VAAPI, even with HEVC 10 bit but as we know still no HDR to SDR conversion in Kodi 17).

My MB has DVI port only so I had to use DVI to HDMI cable, hence 4K was limited to 30Hz and no multichannel Highres audio possible. Unacceptable for me.

The problem is 4K/60Hz in Intel. To this day this is natively supported via DP only but MBs with DP port are very rare. And working DP to HDMI 2.0 adapters (most TVs do not have DP ports, mine doesn't) are rare too. I have one at home from Club3D but this doesn't pass TrueHD/DTS Master.

There are HDMI 2.0 Intel MBs but they use LSPCON chip to convert DP to HDMI 2.0. I'll try to find such MB... No idea why to this day Intel graphics still have no native HDMI 2.0.

I decided to make another step. Since my MB for G4560 did only have DVI, I replaced it with another MB that has DP and HDMI 1.4. But I moved forward, that is decided to go with Cofee Lake Pentium G5600 + MB with H370 chipset. I also bought active Club 3D CAC-1070 DP to HDMI 2.0 adapter. I already owned this adapter and tested it with another setup with good results.

(MBs for Intel with HDMI 2.0 are almost impossible to have. There are like 2 or 3 models in production (doesn't mean they are available to be bought) but all are using onboard DP to HDMI converter since even latest Intel CPUs have only HDMI 1.4. And they very expensive. It's cheaper to go with DP plus that DP to HDMI 2.0 adapter.)

So with the new setup under Windows 10 everything's working correcty - 4K/60Hz (with DP to HDMI 2.0 adapter), sound over HDMI etc. etc.

But LE 8 refused to work completely (X Server not starting up at all), probably due to too new 'UHD' 630 graphics (G4560 has just 'HD' 610).

I upgraded to latest LE 9 alpha then. Now LE is starting up but:

- at 4K I'm locked downto 30Hz, no matter if I use HDMI output on MB (obvious, HDMI is just 1.4) or DP output with DP to HDMI 2.0 adapter. So same problem as with AMD RX 550 I tried previously.

- no matter what I do, I have no sound. Doesn't matter whether I use HDMI output or DP with DP to HDMI 2.0 adapter.

Any advice ?

I guess Intel UHD still too new for latest alpha of LE 9 ?

Now I think I'd do better if I stayed with Pentium G4560 and bought 100/200 series MB for it with HDMI/DP output, rather than moving to 300-series chipset and Cofee Lake with newer 'UHD' graphics ?