AmigaOS maximum resolution (Radeon R5 230)

AmigaOne X5000 platform specific issues.
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nbache
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Re: AmigaOS maximum resolution (Radeon R5 230)

Post by nbache »

tonyw wrote:It certainly looks like a bandwidth limitation to me.
Agree.
I notice that your H freq is very high - nearly 100 kHz. With 2560 pixels across the screen, that needs a bandwidth greater than (2560 x 100 k =) 256 MHz. That is pushing the bounds of the adaptor and cable, not to mention the specification of the DVI interface. Perhaps you need to attract Hans' attention.
I can add that I also have a similar horizontal frequency, 98.76 kHz. I'm using 2560×1600×32@60 on a Dell U3011 monitor. My X1000 has a Radeon HD 6670, and my X5000 uses a Radeon RX 560. Both are connected with DVI DL cables into an ATEN CS1784a KVM, which is also DL specced, and of course with a DVI DL cable from that to the monitor.

And I don't have any of those distortions. I did have them back when I tried using regular DVI (non-DL) gear with that resolution.

Of course there may be an actual hardware fault with one or the other component in Quaros' setup, but otherwise I would suspect the DVI to HDMI adapter or some other issue around the HDMI part of the chain (since that is where the setup differs the most from mine).

Best regards,

Niels
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Re: AmigaOS maximum resolution (Radeon R5 230)

Post by broadblues »

So in 1920x1200 the fonts look nice and readable, in 2560x1600 it gets almost unreadable as you can see in the screenmode preference menu:
26EABE90-132A-48F2-9AA1-3A164E5683D7.jpeg
So what is happening here?
The visible size (2550 1500) is slightly smaller than the nominal display resolution. (2560 x 1600) Could this be causing aliasing problems?

If your monitor has a switchable scaling function try switching it off.
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Re: AmigaOS maximum resolution (Radeon R5 230)

Post by Quaros »

Following the advice of you guys here in the forum I have done some testing on my configuration between AmigaOS and MorphOS:

DVI to HDMI adapter to HDMI cable
- AmigaOS: maximum resolution 1920x1200 without any issue (2560x1600 gives distortions)
- MorphOS: maximum resolution 2560x1600 without any issue

DVI dual link to DVI dual link cable
- AmigaOS: maximum resolution 2560x1600 without any issue
- MorpOS: Not possible to get an image on the monitor?!?

HDMI to HDMI cable
- AmigaOS: Not possible to get an image on the monitor?!?
- MorpOS: maximum resolution 2560x1600 without any issue

It seems that AmigaOS is preferring the DVI port on the video card and is not showing any image when only HDMI is plugged in. MorpOS is preferring the HDMI port on the video card and is not showing any image when only DVI is plugged in. Both HDMI and DVI ports are showing images on the monitor before switching to the graphical modes in either AmigaOS en MorphOS. So I wonder how to proceed now. The best solution seems to be to use the DVI to HDMI adapter to HDMI cable option and to just accept that 2560x1600 is not usable in AmigaOS.

Any other ideas?
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Re: AmigaOS maximum resolution (Radeon R5 230)

Post by trixie »

Quaros wrote:It seems that AmigaOS is preferring the DVI port on the video card and is not showing any image when only HDMI is plugged in.
My experience is the same, using a Sapphire Radeon R5 230 card. No picture past the boot logo when plugged over HDMI.
and to just accept that 2560x1600 is not usable in AmigaOS.
You said

"DVI dual link to DVI dual link cable
- AmigaOS: maximum resolution 2560x1600 without any issue",

so how come 2560x1600 is not usable in AmigaOS?
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Re: AmigaOS maximum resolution (Radeon R5 230)

Post by nbache »

If you need both systems to have full resolution (and I would, of course, if I were using both), maybe an option could be to have both your second and your third solution connected simultaneously, i.e. a straight HDMI cable for MorphOs and a straight DVI DL cable for AmigaOS.

Have you tested that setup?

Best regards,

Niels
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Re: AmigaOS maximum resolution (Radeon R5 230)

Post by Quaros »

trixie wrote:
Quaros wrote:It seems that AmigaOS is preferring the DVI port on the video card and is not showing any image when only HDMI is plugged in.
My experience is the same, using a Sapphire Radeon R5 230 card. No picture past the boot logo when plugged over HDMI.
and to just accept that 2560x1600 is not usable in AmigaOS.
You said

"DVI dual link to DVI dual link cable
- AmigaOS: maximum resolution 2560x1600 without any issue",

so how come 2560x1600 is not usable in AmigaOS?
I am able to get to this resolution but it looks distorted and things are unreadable in AmigaOS. Only 1920x1200 is giving me something I can work with.
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Re: AmigaOS maximum resolution (Radeon R5 230)

Post by Quaros »

nbache wrote:If you need both systems to have full resolution (and I would, of course, if I were using both), maybe an option could be to have both your second and your third solution connected simultaneously, i.e. a straight HDMI cable for MorphOs and a straight DVI DL cable for AmigaOS.

Have you tested that setup?

Best regards,

Niels
Hello Niels,

I thought about that and indeed tested it. AmigaOS is working with both cables (DVI and HDMI) plugged in, but MorphOS is only working while the DVI is unplugged. I am not seeing myself plugging and unplugging the DVI cable just to boot into another OS. It just seems that the display/video drivers for AmigaOS and MorphOS behave quite differently. I am however curious why the behavior is like this? This may lead to a solution. If not I will choose for having a slighly lower resolution in AmigaOS for the time being.

Kind regards,
Vincent
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