Bypass 400MHz VGA Bandwidth?

[rabidz7]

Is it possible to bypass nVidia's 400MHz VGA pixel clock limit?

 

[phillyboy]

You really like to reach into the wayback machine with your questions... .

Try using powerstrip, though there looks like an INI setting needs to be changed to enable higher clocks.

http://entechtaiwan.com/util/ps.shtm
http://forums.entechtaiwan.com/index.php?topic=4270.0;wap2

Looks like someone had the same question as you a few years ago...

http://hardforum.com/showthread.php?t=1733764

http://hardforum.com/showthread.php?t=1733764

I think 500 MHz RAMDACs existed on older ATI cards back in the day, but I'm not 100% sure.

Good luck.

 

[Sn0_Man]

Try ToastyX's Custom Resolution Utility.

I used custom drivers and his CRU to get over the 400MHz cap on DVI on my 670 and while I'm aware that DVI is different from VGA, I'd assume that your best bet for getting it on VGA would be that tool or similar.

If nothing else you can contact him directly and ask him how to do it as he'd be the one to know I think.

 

[feanor1024]

Yes, but you lose HDCP and hardware video acceleration.

 

[houkouonchi]

I am curious why you would need > 400 Mhz RAMDAC. I mean hell the only time I ever used 400 Mhz ramdac was to run 2560x1920@63 Hz on a CRT. And even @ 400 Mhz stuff starts getting a little fuzzy at that bandwidth amount.

What display would possibly take > 400 Mhz pixel clock over VGA?

 

[rabidz7]

I am curious why you would need > 400 Mhz RAMDAC. I mean hell the only time I ever used 400 Mhz ramdac was to run 2560x1920@63 Hz on a CRT. And even @ 400 Mhz stuff starts getting a little fuzzy at that bandwidth amount.

What display would possibly take > 400 Mhz pixel clock over VGA?

I'm trying to send 2880x2160 at 55Hz to my CRT.

 

[flod]

but can you even tell the difference once you're above 1440 lines?

 

[rabidz7]

but can you even tell the difference once you're above 1440 lines?

Everything looks sharper.

 

[phillyboy]

I would think that the dot pitch of the monitor would start to make that a losing battle, unfortunately. My Sony G520 is the same basic specs as yours (21", 0.24mm aperture grill) and you can start to see some hint of fuzziness at 1600x1200.

But hey, nothing wrong with experimenting. Just don't try to sell that monitor here .

 

[spacediver]

Everything looks sharper.

If you have a loupe, I'd be very curious to see how well lines are actually resolved on, for example, a pattern with alternating black and white lines. If you like, I can create some patterns for you to test, at different resolutions.

See this post for an example.

 

[houkouonchi]

I would think that the dot pitch of the monitor would start to make that a losing battle, unfortunately. My Sony G520 is the same basic specs as yours (21", 0.24mm aperture grill) and you can start to see some hint of fuzziness at 1600x1200.

But hey, nothing wrong with experimenting. Just don't try to sell that monitor here .

Yeah, agreed. I was running 2560x1920 on my CRT and it was really starting to get diminishing returns because you start losing clarity but it was still usable.

I was using a 22 inch ViewSonic P225F. If I changed the voltage to lower (it messed with the brightness/contrast but would make text much charper) things got a bit better.

Anyway 2560x1920 @ 63 Hz is 443 Mhz pixelclock if using gtf timings. Which isn't that much higher than 2880x2160@55 Hz (486 Mhz). You can likely tighten the timings a bit to get the modeline a bit closer to 400 Mhz.

That being said running a CRT at < 60Hz really sucks. Back in the day I did that on my P225F @ 2560x1920 simply because back then all the hardware had 350 Mhz RAMDAC's and I ran at 54 or 55 Hz and you can really see the flicker pretty bad at that refresh rate. Hell I even see it until I start exceeding around 80 Hz but it doesn't bother me too bad at 60.

If you wan't really high resolution why not just buy a 4k LCD? The clarity you get on an LCD (especially at high resolution) kicks the crap out of a CRT. I remember when I first got my 3840x2400 resolution 22 inch LCD. Way smaller pixels than the 2560x1920 I had on the 4:3 22 inch CRT yet much more crisp and easier to read text even though the text was quite a bit smaller.

 

[rabidz7]

I don't want any post and hold motion blur and I also like the color and contrast of a CRT.

 

[feanor1024]

Diamondtrons where were it was at. My 22" Diamondtrons were sharp at 2048x1536 but my Trinitrons were fuzzy at anything over 1280x960.