[mythtv-users] overscan problems with nvidia 8400 GS

Tortise tortise at paradise.net.nz
Fri Jul 17 23:26:55 UTC 2009

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 
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.
> </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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