Do you just want DisplayPort to VGA? The Sunix DPU3000 you mentioned was a triple display device that had DP, HDMI, and VGA output.

Pretty much any DP to VGA adapter on the market handles up to 1080p 60hz. Maybe go with a $12-15 adapter versus the $7-8 if you are worried about the quality.

But do you have any specific use case you are thinking about? Anything you buy nowadays would be the same DACs and they are still actively used in things like USB-C adapters that include VGA output as well as USB-C docking stations.

SScorpio wrote on 2022-10-08, 16:24:

Do you just want DisplayPort to VGA? The Sunix DPU3000 you mentioned was a triple display device that had DP, HDMI, and VGA output.

Pretty much any DP to VGA adapter on the market handles up to 1080p 60hz. Maybe go with a $12-15 adapter versus the $7-8 if you are worried about the quality.

But do you have any specific use case you are thinking about? Anything you buy nowadays would be the same DACs and they are still actively used in things like USB-C adapters that include VGA output as well as USB-C docking stations.

I am going to guess that some of the cheaper adapters might have image quality issues when running at high resolutions and/or refresh rates, not due to the DAC, but because of the design of the analogue output stage. That being said, I have seen a 10$ generic one running through a VGA port on a 24" LCD at 1080P 60Hz and it looked fine at a glance .

Though it's hard to find any analog VGA hookup that doesn't go to shit at over 1080P

BitWrangler wrote on 2022-10-08, 17:42:

Though it's hard to find any analog VGA hookup that doesn't go to shit at over 1080P

The main question is, is there really a use case where running such high resolutions (>1080p) over VGA (analogue RGB) is either unavoidable or presents an advantage over using DisplayPort or HDMI ?

How is the HDfury X4? It’s listed at 225 MHz but only has an HDMI port.

sofakng wrote on 2022-10-08, 19:47:

How is the HDfury X4? It’s listed at 225 MHz but only has an HDMI port.

That has a scaler rather than just having a DAC going from digital to analog.

I also could be wrong, but I believe VGA will top out at 2048x1536. Honestly, the cheap DP to VGA adapters offices use to get new computers working with their old monitors are just fine at 1080p 60Hz.

What are you trying to do?

SScorpio wrote on 2022-10-08, 20:46:

That has a scaler rather than just having a DAC going from digital to analog. […]
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sofakng wrote on 2022-10-08, 19:47:

How is the HDfury X4? It’s listed at 225 MHz but only has an HDMI port.

That has a scaler rather than just having a DAC going from digital to analog.

I also could be wrong, but I believe VGA will top out at 2048x1536. Honestly, the cheap DP to VGA adapters offices use to get new computers working with their old monitors are just fine at 1080p 60Hz.

What are you trying to do?

(S)VGA itself (analogue RGB with separate H/V sync) has no concrete theoretical upper limit, AFAIU.
2048x1536 is likely a common limit imposed by the RAMDACs that are (were?) available either as discrete components or integrated into VGA controllers (or GPUs). I have no idea if CRT monitors actually capable of accepting and displaying resolutions much above that were actually commonly available or not .

That being said, as @SScorpio asked, I too would like to know what the aim, objective or prospective use case is for the VGA DAC in question .

darry wrote on 2022-10-08, 22:04:

(S)VGA itself (analogue RGB with separate H/V sync) has no concrete theoretical upper limit, AFAIU.
2048x1536 is likely a common limit imposed by the RAMDACs that are (were?) available either as discrete components or integrated into VGA controllers (or GPUs). I have no idea if CRT monitors actually capable of accepting and displaying resolutions much above that were actually commonly available or not .

That being said, as @SScorpio asked, I too would like to know what the aim, objective or prospective use case is for the VGA DAC in question .

Ya, my understanding is that it isn't a hard limit. But more of the signal degrading past that. I'm not sure if it's down to the RAMDAC or if better cable shielding would allow for higher resolutions.

But outside of some exotic professional gear, anything with a higher resolution would have had at least DVI or HDMI interfaces by then. I have consumer CRTs that can do 1600x1200, and that 1080p that people drool over includes both DVI and VGA.

SScorpio wrote on 2022-10-08, 23:08:

Ya, my understanding is that it isn't a hard limit. But more of the signal degrading past that. I'm not sure if it's down to the RAMDAC or if better cable shielding would allow for higher resolutions.

That's what I'm meaning really. Gotta have good quality cabling to get the signal there. Plus if the monitor maker, late in the VGA game, didn't really care, and the VGA output supplier did it halfassed, then they may not have done a 100% job on impedance matching trace to chip and filtering and even good cable is just gonna help the reflections bounce better*. Then also you get aging output filter caps on older cards which leaves output muddier than it should have been through their VGA ports.

It's the general problem with a lot of stuff for getting a decent VGA cable nowadays, the cheapest ones are probably to be avoided, the mid price ones may actually be decent or they might be the $5 ones in fancy package, then the high end ones might be absolute overkill and charge you accordingly, or be the same as the reasonable construction midrange in a fancy package. I don't have to worry about it, since I have a variety of cables in decent shape and can just swap them round until one works bearably enough.

*in such a situation it may be that a moderately crappy cable actually looks better than a really good one, as long as there's not also a lot of local noise that it should be excluding and won't.

BitWrangler wrote on 2022-10-08, 23:31:

That's what I'm meaning really. Gotta have good quality cabling to get the signal there. Plus if the monitor maker, late in the […]
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SScorpio wrote on 2022-10-08, 23:08:

Ya, my understanding is that it isn't a hard limit. But more of the signal degrading past that. I'm not sure if it's down to the RAMDAC or if better cable shielding would allow for higher resolutions.

That's what I'm meaning really. Gotta have good quality cabling to get the signal there. Plus if the monitor maker, late in the VGA game, didn't really care, and the VGA output supplier did it halfassed, then they may not have done a 100% job on impedance matching trace to chip and filtering and even good cable is just gonna help the reflections bounce better*. Then also you get aging output filter caps on older cards which leaves output muddier than it should have been through their VGA ports.

It's the general problem with a lot of stuff for getting a decent VGA cable nowadays, the cheapest ones are probably to be avoided, the mid price ones may actually be decent or they might be the $5 ones in fancy package, then the high end ones might be absolute overkill and charge you accordingly, or be the same as the reasonable construction midrange in a fancy package. I don't have to worry about it, since I have a variety of cables in decent shape and can just swap them round until one works bearably enough.

*in such a situation it may be that a moderately crappy cable actually looks better than a really good one, as long as there's not also a lot of local noise that it should be excluding and won't.

Even getting "perfect" 1600x1200 over VGA can be a challenge . Re: VGA Capture Thread

I now have more large gauge shielded VGA cables than I will ever need, a lifetime supply of assorted ferrite cores and 2 OSSC units. Unfortunately the cables might all be at least a bit off in terms of impedance and so is my Voodoo 3, in all likelihood .