50 hz with latest nvidea drivers

[basser]

hello everyone ...just installed nvideas newest drivers (185-85) directly from them.
i installed ,went to nvidea control panel/then to "change signal or hd format".
then at the top of the box a new setting was shown "1080 50 hdtv".

As i have a uk pal 1080 lcd tv,i used this setting.....must say films look really good with it but srolling text shimmers badly........does anyone have any info on this new setting of 50 hz and should we se it?

 

[stevelup]

Hi

If you're talking HD movies, then they will be 24FPS so you would need to be outputting 24, 48 or 72Hz to get judder free playback.

The only time you would want to use the 50Hz output is if you were playing back PAL DVD or rips from 50Hz TV sources.

Steve

 

[Stephen Neal]

If you are watching UK or European DVDs or SD/HD TV then 50Hz refresh is a must. If you watch European TV or DVD at 24Hz you will get horrible jerkiness, and if you watch at 60Hz will add 10 extra repeated frames each second, which will give motion a repeated juddery look. This is REALLY obvious on the tickers on Sky News or BBC News.

If you are watching 1080p Blu-rays, or HD-DVDs, then you need 23.976Hz (nVidia call this 23Hz) IF your TV has a "24p True Cinema" or similar mode. (Confusingly you don't want to select a 24Hz refresh if your drivers offer 23Hz - as that will cause occasional stuttering)

If you are watching almost any 1080i Blu-rays (*) or US SD/HD TV then you need 59.94Hz (nVidia call this 59Hz). Confusingly you don't want 60Hz - even though these formats are commonly described as 60Hz - again 60Hz refresh may introduce some stuttering.

The reason you want 23.976 over 24 and 59.94 over 60 is that when the US introduced NTSC colour in the 1950s, they altered their field rate from 60Hz to 59.94Hz to avoid the colour signal subcarrier interfering with the sound subcarrier. This had a knock on effect for film - which shifted from 24Hz to 23.976Hz so that when pulled-down 3:2 it shifted from 60Hz to 59.94Hz.

(*) Almost all 1080i Blu-rays are 59.94Hz - but at least one BBC release (Being Human) is apparently - thankfully - a 50Hz release, improving picture quality by avoiding a 50Hz to 59.94Hz conversion.

I run my nVidia 9400 IGP HTPC at 23Hz for 1080p Blu-ray, 50Hz for Freeview and Satellite - both SD and HD - and 59Hz when watching 1080i Blu-rays.

 

[garnat]

I've got a 9400 IGP as well hooked up to an LG 42PG6000 plasma via HDMI.

I can only see refresh rate options of 25, 29, 30 and 60 available in the nvidia control panel. I believe 60 is the native refresh rate of the TV.

I'm noticing a fair amount of judder on freeview on all settings (25 just looks awful completely) , I haven't tried blu ray yet but I do want to use it for this as well very soon.

Is this a limitation of my TV? Any suggestions getting optimum freeview and blu ray playback?

Cheers

 

[BenTheBookie]

Thanks for that post Stephen....always wondered why I had 23Hz refresh, and now I know!

 

[Stephen Neal]

I've got a 9400 IGP as well hooked up to an LG 42PG6000 plasma via HDMI.

I can only see refresh rate options of 25, 29, 30 and 60 available in the nvidia control panel. I believe 60 is the native refresh rate of the TV.

I'm noticing a fair amount of judder on freeview on all settings (25 just looks awful completely) , I haven't tried blu ray yet but I do want to use it for this as well very soon.

Is this a limitation of my TV? Any suggestions getting optimum freeview and blu ray playback?

Cheers

What resolution are you sending?

You may find that 1280x720 at 50Hz looked better than 1920x1080 at 25Hz - as the former will be progressive and the latter interlaced.

 

[garnat]

It does appear to be related to the resolution. The native resolution of my display is 1024 x 768 which appears to limit my refresh rate choices. Selecting other resolutions opens up the refresh rate choices but look terrible.

Is this a limitation of my TV or an issue with the graphics card/drivers?

 

[garnat]

Some searching has revealed a number of references to a utility called powerstrip, anyone have any experience of this? It looks like it might give me the control over the output refresh rate I'm after.

All I want to do is get 50hz for freeview and 24hz for blu ray to minimise any judder.

 

[stevelup]

It really depends on your display. Some displays will only accept standard PC refresh rates at PC resolutions, others are more tolerant.

Your display is certainly advertising via DDC that it can only accept PC refresh rates at 1024x768 but that's not to say it won't display a picture if you force it.

You can download and try Powerstrip free of charge so no harm in giving it a whirl.

Steve

 

[jameson_uk]

The native resolution of my display is 1024 x 768

Are you sure? You say you have a LCD TV but most LCD TVs have a native res of 1366x768 (16:9). It tends to be older plasmas which have 1024x768 (4:3 ratio so pixels are actually rectangular to make 16:9)

What model TV is it? How are you connecting? (VGA or HDMI?)

If using VGA there is a good chance that it either can't or won't broadcast the fact that it can accept its native res over VGA.

 

[garnat]

The original poster has an LCD, I have LG 42PG6000 plasma connected via HDMI.

We both had similar problems.

 

[Stephen Neal]

Yep - 50Hz over VGA is pretty patchy in support, as are HD resolutions. Many displays will happily accept 50Hz HDMI sources, but are 60Hz only for VGA.

Some drivers will only output 50Hz and 23/24Hz frame rates at HDTV resolutions (1920x1080 or 1280x720) and only output at 60Hz with VGA resolutions (1024x768, 800x600, 1280x1024 etc.)

 

[garnat]

I think I've solved my issue, the native resolution of the LG 42PG6000 plasma is 1024 x 768, however it accepts a full 1080p signal. Vista was recognising the display as a 1080p display and I was overiding it back to down 1024 x 768 to get the display looking usable. It looks like the only 1 HDMI port (port 1) supports 1080p input fully and the others might give strange results. I was not using the correct port! According to the specs online I should be able switch between 24 and 50 hz at 1080p using the correct port.

Will give it a try this evening.

 

[Stephen Neal]

You might find that Windows is more useable at 1280x720. A 1920x1080 desktop scaled to 1024x768 non-square pixels for display on your plasma may make fine text very difficult to read - though if you can run 1920x1080 you'll avoid an extra scale.

 

[garnat]

Increasing the windows font size makes it just about usable at 1080, I'll give the 720 option a go as well, at least I have some choices now to decide which looks best.

Whats the best way way to script resolution changes with the nvidia drivers so I can quickly switch between them in case I found TV is better on one and blu ray is better on another for example?