2008 macpro to vga in 1080p tv aspect issue

Discussion in 'Mac Pro' started by thestudentisrea, Dec 17, 2010.

  1. thestudentisrea macrumors newbie

    Jun 23, 2009
    When I got my lcd tv, I hooked it up, and it worked, so I just forgot about it...

    ... but now I'm doing some video work, and I notice it's slightly stretched horizontally, so I want it set right

    The tv said it was 1080p capable. I don't remember if there was any limitation for vga port.

    When I look at vga display window in system prefs, i see that computer is set for 1600x1200.

    I'm looking for a 1920x1080 setting, but it's not there. next up is 1920x1440

    The tv has two aspect ratio settings, "normal" and "wide"

    I had it on "wide" which is surely why it was stretching everything.

    So... I fixed it. I set it on normal, and checked with a ruler to verify that a square is now, indeed, a square.

    Problem is it letterboxes the screen.

    If I do "detect displays", I still only get options with 4:3 aspect ratio.

    Is this a limitation of vga port?

    Do I need to get dvi to hdmi adaptor and go in that way? If so, will "detect displays" give me the proper 16:9 options?

    Do I need to download 3rd party software like I did for my mac mini a few years ago?

    It's a cheap proscan tv... not sure of the exact model, but it does everything else just fine.

    not sure what to do.
  2. Mackilroy macrumors 68040


    Jun 29, 2006
    That's what I did, though I didn't really worry about it (got a DVI-HDMI adapter for free). The adapter gives me 720p and 1080p in addition to the 4:3 options I already had with the VGA cable I formerly used.
  3. thestudentisrea thread starter macrumors newbie

    Jun 23, 2009
    OK... $60 DVI to HDMI cable later, and...

    ...Now it's much worse.

    Display heading (where it used to say "VGA Display" now reads "PHD5039NUS"

    My resolution options after detect displays are now
    1024 x768
    1024 x 768 (stretched)
    1280 x 960
    1344 x 756
    1344 x 1008
    1366 x 768
    1600 x 900
    1920 x 540

    and I have an "overscan" button.

    The 1600 x 900 appears to be the right ratio, but when selected, it shrinks the screen so black all around.

    If I hit "overscan", it blows up image to slightly and rather irritatingly larger than actual screen... and with quite unacceptable pixel width issues.

    Obviously I want 1920 x 1080.

    Does the fact that it's showing 1920 x 540 mean it's only capable of 1080i? I could SWEAR I triple checked that it was 1080p when I bought it, and I'm now going in HDMI.

    Ps. There is no option now... If I go into tv menu for aspect, it shows "wide" only.
  4. thestudentisrea thread starter macrumors newbie

    Jun 23, 2009
    Tried switchresx as suggested elsewhere, and it can give me 1920 x 1080 otion which will display, but 1.5-3 inches of black all around edges, and some pixel width issues.
  5. thestudentisrea, Dec 17, 2010
    Last edited: Dec 17, 2010

    thestudentisrea thread starter macrumors newbie

    Jun 23, 2009
    I just saw that I had missed there is a 1080p option when going through the hdmi and not running switchresx... missed it as it is listed above the very low res settings as 1080p... and not as 1920 x 1080

    Anyway, uninstalled switchresx, selected 1080p, and same issue as with switchresx...

    It will display with 1080p selected, but screen is shrunk a bit all around, and some pixel width issues so text is a bit off looking.

    Someone must know how to get around this.

    tv option still shows only "wide"

    I seriously don't know what to do now. I tried plugging vga back in to double check and make sure there wasn't another option I'd missed for display resolution, but now I can't even get anything on the monitor in vga mode since settings have been changed for hdmi options...


    Bottom line:

    I need to get 1080p to my tv from my macpro, and while it does give me that option in prefs, screen is shrunk and clearly squishing things a bit unevenly.

    I don't even know how to get back to vga mode now.
  6. goMac macrumors 604

    Apr 15, 2004
    Yes, this is called overscan. All tvs do this automatically.

    The internets seem to be full of people complaining about this issue with this modal of TV. Unlike most tvs, this modal doesn't seem to have any way to turn the overscan off, sorry.

    Mac OS X might give you overscan correction in the Displays control panel, but it will result in a further loss of image quality.
  7. thestudentisrea thread starter macrumors newbie

    Jun 23, 2009
    OK, so... 8 solid HOURS of research and trial and error later, and here's what I've found.

    IT DEPENDS ON YOUR TV. After hours of digging about ATI graphics card over/underscan issues, etc... some tvs have controls for 1:1 pixel mapping, overscan controls on hdmi inputs... AND SOME DON'T. Mine doesn't.

    Actually, going through the hdmi input at all no matter what else you do causes unfixable problems if you have my particular tv. There is actually no way to make it work. The issue has to do with how it interperets and shrinks the incoming signal. To make things worse, my particular mac with it's particular ati card has only an overscan button with no slider, so the only other option is an oversized screen with menu bars cut off.

    Anyway, it doesn't matter, because once I figured out to start in safe mode, delete my display preference, and restart, I was able to get it going on the vga input again.

    Once I did that, it was a simple matter of using switchresx to add a custom resolution of 1920 x 1080. Ok... I had to read a bit of the manual, but it was a very simple case requiring no further tweaking.

    So... done. It looks perfect. No flicker... text looks smooth. No problems.

    Good news. I can't use the hdmi adapter cable at all, so I'll have to return it...


    Bad news. There's no way to make it work on my tv WITHOUT switchresx or similar program. Apparently, the tv tells the mac to ONLY allow 4x3 aspect ratios when connected via vga input. Switchresx is required to override this on the mac's end.

    -$20 or so... I'll have to check. It's on a demo right now.

    Overall, though, it works out perfectly as vga gives me perfect 1:1 pixel mapping, so it's all good in the hood.
  8. ActionableMango macrumors G3


    Sep 21, 2010
    I'm glad you worked it out.

    In the future, you can get more reasonably priced cables from monoprice.com. You shouldn't have to pay $60 for DVI->HDMI.

    Also, consider a better TV next time. :)
  9. thestudentisrea thread starter macrumors newbie

    Jun 23, 2009
    I figured radio shack would be better than anything else local.. they tend to be cheaper than best buy for that kind of thing. Generally, it seems that cables at places that specialize in the sales of the tv's or other big ticket items are overpriced as they are afterthought addons. I guess they (probably correctly) figure that people aggressively price shop the tv's, and they need to make their margins on cables, warrantees, and credit programs.

    I know I could do better online, but I needed it immediately.

    Why get a better tv when I have a perfect solution with $19 worth of software, and a 40 inch 1080p display that pixel maps the output exactly for $400? (It did have me a bit scared 'till I got it working, tho.)
  10. goMac macrumors 604

    Apr 15, 2004
    For future reference, I got a DVI-HDMI from the Apple store for $20.

    Cause if you have a game console you plug in via HDMI, you'll also lose content, and lack of 1:1 also usually means a loss in quality. Also VGA is teh suck for image quality. (I ran a computer through VGA on a HDTV for a while, my color balance was always off and I got flickering.)

    Usually with TV's it's a good idea to make a decent investment in something higher quality, both for hardware failure rates and software quality. 1:1 pixel mapping is a fairly standard feature these days. My 4 year old TV has it.
  11. JonBook Pro macrumors member

    Feb 22, 2010
    Not really.

    What are you talking about? Just because you can't figure something out in your own right doesn't mean it's applicable on a widespread basis. I've seen many demonstrations of successful VGA runs both personally and professionally. It's widely flexible in comparison to its digital counterparts and it's still being used today.

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