Hi,

I have a PowerMac G5 @ 2.5GHz (PowerMac7,3) running MorphOS 3.14, with a Radeon9600XT 128MB graphics card @ 1920x1080 thru DVI without issues. Since I got a new monitor that takes 2560x1440, I wanted to use that mode, and while it shows on the monitor mode list, it is not available to select on the Screens preference. If I edit the mode and press "Test", MorphOS freezes (or looks like it - the image freezes and the mouse cursor disappears). I've been trying to find out if this Radeon 9600XT 128MB (Mac version) supports dual-link DVI, but without much success. Any help/pointers will be appreciated.

Thanks

AFAIR only the 256MB version (found in the 2x2.7GHz) has DualLink-DVI.

As for that mode being listed, at what frequency (it is possible to run such a resolution at 30Hz)?

There also was an issue bout DualLink-modes being activated without DualLink-HW being present which might explain your issue, but AFAIK that had been fixed for the 3.14 release.

Maybe not really the same use case, but I am currently using an AGP Radeon 9700Pro with a 2560x1440 output on a Pegasos2/G4. I had to create the screen mode manually but it works with no issue here. My Radeon is connected to the monitor thru a DVI-HDMI cable. BTW, this Radeon is not dual-link, which is not an issue here. :)

[ Edité par OffseT 28.12.2020 - 19:32 ]

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Well even if it was DualLink, that would have been gone by the use of that cable as converting HDMI/DP to DualLink (or vice versa) requires an active adapter.

So pretty sure you are running at 30Hz or maybe a bit higher (as it would be maxed at 30Hz for 2560x1600).

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It's listed at 59.9Hz.

Hi everyone,

It's not too often that i log in (though i do follow morph.zone almost daily since ages ...), and even less often when i ask something, but now i have a question about that dual-link DVI to ... something adapter.

I want to "build" a perfect MorphOS machine, preferably a silent G5 PowerMac. If there is/can be such a thing ... :D

I bought a 2.7GHz PMac G5, with a 256MB Radeon card. It supports 1440p@60Hz, but (as it seems) it needs an active dual link DVI to HDMI/DisplayPort adapter.
Does anyone uses MorphOS at 1440p resolution with such an adapter?
If yes, which one? I saw a Club 3D, it's about 50 EUR. I would buy it, but i would like to know if it would really work, or perhaps there's a better/cheaper solution.

Thanks in advance.

>>I saw a Club 3D, it's about 50 EUR.

Careful, thats most likely one for the wrong direction.

I did some searching in the last days as i might try getting a 4k running at 30Hz (same bandwidth as 1440 at 60) and this is what I might try hunting down:

https://www.gefen.com/product/dual-link-dvi-mini-dp-converter-GTV-DVIDL-2-MDP

No idea wether it will work, but is at least the right direction.

Wow! That's a "little bit" more expensive than 50 EUR :D About 7 times more (where i have found it) ... :D

Btw. you are right, i have checked it, those Club 3D adapters are actually HDMI/DP to dual link DVI.

Mmmm yeah just checked and the cheapest I found on ebay was 138€ from Poland. Much pricier that I remembered (but I just can't find THAT offer) but still a long way from the 350 you are suggesting.

There also was another device I've looked up some years ago (when it was of no urgency as my best monitor at that time was a Dell featuring DualLink) that would go for about 100$/€ but I just can't remember what that actually was.

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Following up on this, I did more tests and found out the following:

- MorphOS doesn't freeze; if I press escape I get back the mouse cursor and can continue working as normal.
- I can't test any screen mode at all (not even 1080p, which is the one I'm using), I always get the same behaviour.
- I tried to do the same test by booting from the 3.13 CD and I get the same behaviour.
- If I boot from the 3.12 CD however, I get a picture with garbled colours (might post a pic later), BUT if I navigate my way to the mode edit (despite the image being severely garbled), I can test all available screen modes and they show up correctly.

Any ideas? :\

Thanks

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My screen mode is 50Hz (higher freq are not stable).

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It's exactly 353 EUR where i usually buy stuff :(

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I think i'm just gonna buy a 1440p monitor with dual link DVI input.

I've found today an older 27" 1440p monitor in my closet (the panel is a bit yellowish ...), hooked it up to the G5 through dual link DVI, and voila! It works perfectly! :D MorphOS is so beautiful in 1440p!!! :D

It's just that i'm so spoiled with the iMac 5K, that when i drag a window from it to a 27" 1440p, even the 1440p's screen looks washed out and pixelated ... It pisses me off :)
And not to mention the 24" 1080p monitor ... it's like the difference between a 17" CRT and a 24" 1080p ...
And it was not long ago that i watched movies on that 24" 1080p, and it seemed huuuge ... :D

Anyway, those active adapters are just too expensive. I can't justify to myself 200-300 EUR for it, when a new 2K monitor costs 250-300 EUR ... :)

Ok so (luckily) I was able to get a Mac Radeon 9800 with 256MB (R350 0x4e48) and swapped it with the 9600 XT. However things are not much better. Although I have modes > 1080p available in "Monitors", they do not show up on "Screens" - max resolution that shows up there is 1680x1050 (while with the 9600 XT I could at least use 1080p). I can edit (and test) modes > 1080p now (so the bug I had before is gone with this card), but I can't use them. Am I missing something obvious here?

Thanks

I have the same card in my assortment (with misaligned DVI-connector so it won't really fit in any case) and it is NOT what you think it is...


This card was made to work with both G4s and G5s (and is thereby limited to AGPx2) and it does NOT feature DualLink-DVI.


Known to be working:

Radeon9650 (as found in the 2x2.7GHz G5)
Some late PowerBooks with 128MB VRAM
???

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Be that as it may, it still doesn't explain why I can't even use a 1920x1080 screen, while it works perfectly in Mode edit, right?

Also, I can edit modes with pixel clock > 200MHz just fine (like 2560x1200 @ 65Hz). Things get glitchy above 230MHz though...

Thanks

I can only guess, but if you are still connected to a monitor >FullHD communications might get a bit confused.

There is that chip that could do those higher res, but it isn't wired up to use them and there is a monitor reporting those higher res or even total nonsense....

Options:
- Test with another monitor

- When in Mode edit hit "test" on something FullHD or higher

- Modify a mode that is shown up in Monitor to FullHD. Thats how I way back in MorphOS1.4 I created a 1920x1200 mode when all that was on offer were 4:3 modes maxing out at 1600x1200 (or maybe even lower).

[ Edited by Kronos 07.01.2021 - 19:54 ]

After much troubleshooting (thanks @Kronos), I was able to get resolutions >1680x1050 working by reverting to the previous version of the Radeon device driver (52.36). With 52.37 I can't go above 1680x1050 no matter what I do. There are issues with this particular card going above 230MHz, but I am now running stable 2560x1440 @ 57Hz.