[mythtv-users] overscan problems with nvidia 8400 GS

Dale Pontius DEPontius at edgehp.net
Sun Jul 26 20:29:37 UTC 2009

One other datapoint...

When booting, the nVidia gives me TV-Out of a framebuffer, showing the
boot console.


I don't always get perfect sizing of the console on my direct VGA/DVI
connections, yet nVidia gets it perfect through the TV-Out.  So the
hardware can and does do it.

Just not under X-Windows.

Dale Pontius
Tortise wrote:
> Hi Dale
> I believe while NVIDIA may have a little to answer I believe your Sony TV has much more, as that is the real source of the problem.
> I understand any >= 8xxx NVIDIA card will give you the same result over component.  (I can confirm same happens with a 8500GT and 
> 9400GT)
> Some of the old CRT's have some distinct advantages, better blacks, wider viewing angles etc so in many respects they remain better 
> than LCD, the most recent possibly catching up!  (Some dinosaurs endure today....so they have a lot of experience to pull on!)
> I am sure Sony (or whoever you choose) will love to see one of your kids leave home early!
> What model of Sony TV do you have?
> Is it in warranty still?
> Do you have or is a pdf of the manual available?
> What do Sony say it should do over component?
> ----- Original Message ----- 
> From: "Dale Pontius" <DEPontius at edgehp.net>
> To: "Discussion about mythtv" <mythtv-users at mythtv.org>
> Sent: Saturday, July 18, 2009 11:10 AM
> Subject: Re: [mythtv-users] overscan problems with nvidia 8400 GS
> Brian Wood wrote:
>> On Monday 06 July 2009 07:52:25 Johnny wrote:
>>> It is true that overscan is caused by the TV and not the video card,
>>> however, the problem of displaying stuff from a computer on a TV is
>>> shared by the TV and the video card. In the case of SD TVs, they were
>>> never intended to be hooked up to a computer and so it is unreasonable
>>> to hope for them to fix this issue. So in my opinion, if Nvidia
>>> provides a TV out option they do have some responsiblity to help me
>>> display stuff correctly on that TV (especially since overscan is
>>> standard in many many TVs).
>> Another history lesson:
>> Why is overscan standard?
>> In the "Old Days" (defined as a block of time that ended the day you were
>> born) virtually all TV sets came from the factory overscanning to an extent.
>> The reason is because as the TV set aged, many things tended to change with
>> time: capacitors would get leaky, tubes would lose emission and other bad
>> things would happen. Unfortunately just about all these changes tended to
>> reduce voltages in the set, and result in under scanning.
> <snip>
>> </history lesson>
> I don't buy it.
> I don't doubt what you say, and I can agree that your history is
> perfectly valid.  I just don't believe it explains what I see on my
> setup.  You appear to have essentially "absolved" nVidia of any "guilt"
> with the 8000-series and overscan, by saying it's all a specmanship
> problem with NTSC and overscan from day-1.
> I have one of those clunky old NTSC CRT sets. (A Sony, if it matters.)
> I know we're dinosaurs, but we've also got 2 kids in college.  Current
> plan says that the first kid out of the house gets a TV, and we get a
> new one.
> This TV has never had serious visual problems with anything we've hooked
> up to it.  That includes VCR through RF, VCR through composite, VCR
> through svideo, DVD player through composite video, DVD player through
> svideo, and DVD player through component video, and several of the kids'
> friend's games consoles.  No visually annoying overscan problem, but you
> probably wouldn't expect to see any with that range of hardwared.
> But I've also driven that same tv from a laptop with svideo out, again
> with no noticable visual/overscan problems.  (Incidentally, Radeon
> Mobile)  Oh, and my daughter's boyfriend's Mac also drove the TV just
> fine through composite.
> Out of all this hardware, the ONLY thing driving the TV that has had ANY
> problem is the nVidia 8400GS in the Myth frontend I'm building - the
> machine that is essentially stalled for several reasons, this being one
> of them.  ("The picture's kind of blurry",  Well OF COURSE it's blurry
> when the video's being close-rescaled because I'm letting Myth resize
> the picture to compensate for overscan.)
> So I don't deny what you've said - but I insist that what nVidia has
> done is way above and beyond what you've said - they've shipped a BROKEN
> product if you're one of those dinosaurs driving a CRT.
> Ya know, the nVidia 6200 in the machine I'm using now is kind of a
> stinker - slow.  I might make sense to give up on the TV-out of the
> 8400GS and move it to this machine.  But what should I get instead?  One
> really nice thing about the 8400GS I got was that it would drive
> component video, presumably to give me the best picture - until I had to
> compensate for overscan.
> Dale Pontius
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