VOGONS


First post, by adadak

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Dear all,
I've recently acquired an HP p1230 CRT (rebranded Mitsubishi 2070SB). As my RX 570 had no VGA output, I bought a DVI-D -> VGA adapter pictured below. It works fine at lower resolutions which are supported at up to 85 Hz refresh rate. The thing is that the native resolution of the monitor is incorrectly recognized and I'm unable to set the optimal resolution which is 1600x1200 at 85 Hz. I managed to create such a custom resolution in the Radeon settings although I couldn't exceed the 60 Hz limit as the Radeon software claimed higher refresh rates were incompatible with my display. Also, the settings I made in CRU are only shown if they are below 60 Hz - 1600x1200 at 85 Hz won't show up even if it's listed in the registry as a preferred mode. I installed the original monitor driver from HP but it made no difference. How to force 1600x1200 at 85 Hz?

Reply 1 of 4, by Doornkaat

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Sorry but the adaptor in the picture is an active converter that converts the digital DVI-D signal to an analog VGA signal. It likely doesn't support 1600*1200@85Hz.
Edit:
Btw. there's a chance the converter supports higher refresh rates by skipping frames. With inexpensive converters the output is often fixed to 60Hz to avoid problems with LCDs that don't support refresh rates higher than 60Hz.

Reply 2 of 4, by Tiido

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All these DVI/HDMI dongles are limited to 165MHz pixel clock from what I have seen, and 1600x1200 @ 60Hz is right at the end of support for them and you will not be getting 85Hz out of them unfortunately.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

Reply 3 of 4, by adadak

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That kinda sucks! Is there even any alternative? I haven't found anything which is not a cheap Chinese dongle

Reply 4 of 4, by Tiido

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It is a limit of single link DVI itself, 165MHz is max official spec for it and nobody ever broke it. Similarly HDMI dongles top out at that, with 1980x1080 with reduced blanking being right at the edge of support for them.

There are some DP to VGA dongles that can go beyond the 165MHz pixel clock limit but I don't remember the model numbers. They're very expensive though...
Video card with VGA output (DVI-I will work too with the passive adaptors). is likely least expensive and at the same time most versatile solution, since VGA ports pretty much always go up to 400MHz.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜