PC Doens't give me option higher than 1360x768 on 1080p tv?

Discussion in 'Home Theater PCs & Equipment' started by coder_t2, Aug 25, 2011.

  1. coder_t2

    coder_t2 [H]ard|Gawd

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    Hey guys, I have had by HTPC hooked up via VGA to my 720p Samsung for a few years. Just got a new 1080p TV, and my PC isn't giving me any options higher than 1360x768. Any idea what I need to do to force it to 1080p? Or what my problem is? Thanks.
     
  2. valve1138

    valve1138 [H]ardForum Junkie

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    There should be something in there about HDTV modes and enabling them.

    What kind fo graphics card is it?
     
  3. coder_t2

    coder_t2 [H]ard|Gawd

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    Just intel IGP. G41 chipset. I believe GMA4500.
     
  4. Telo

    Telo n00b

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    Is the VGA input the only one that supports PC video on your particular TV? If the HDMI inputs can support it, try sending the signal via a DVI to HDMI converter or cable; if you card has an HDMI output you can use that as well.

    Sorry, didn't see the reply about being on board video. Does your mobo have an HDMI output?
     
  5. coder_t2

    coder_t2 [H]ard|Gawd

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    It does not. Otherwise I'd be using it for sure. And I can't add in a separate video card because my PCI-Express slot is taken up by my TV Tuner, since my PCI-E 1x slots cause the TV Tuner to bump into the RAM. I updated the drivers, and now I have the option to go up to 1896 x 1080. However, my TV keeps giving me unsupported video. And yes, the TV is definitely 1080p. It is a LED Toshiba. It keeps thinking the optimal resolution is 1360x768
     
  6. guney

    guney Limp Gawd

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    You might be hitting that limit because of the fact that you're using a VGA connection.

    VGA connections are analog and, if you look it up online, you'll read that there is no technical upper limit to the resolution of the image they can carry. However, practical limitations are applicable based on what the VGA circuitry of your graphics adapter can produce, and (less likely) what the display is able to accept and show.

    The analog signal transmitted over the VGA cable is essentially generated by the RAMDAC of your graphics adapter. (As the name implies, this is a "Digital-to-Analog Converter" chip.) Before the days of DVI connectors, graphics card manufacturers used to tout the specs of their RAMDACs with pride. These days, you don't even see them mentioned.

    It might very well be that in this age of digital display connections, the RAMDAC in your graphics adapter is an afterthought that's thrown in just to support business projectors for office presentations, rather than a chip that can support high enough frequencies to transmit HD over VGA. You might want to look up the specs of your adapter's RAMDAC. Most likely, it will be expressed in "MHz" rather than any pixel count; but you should be able to google around and pretty quickly come up with the information on how that can be converted to a given pixel resolution.
     
  7. coder_t2

    coder_t2 [H]ard|Gawd

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    The graphics adapter should be able to do 1080p. There is a another version called the GMA4500HD, and the only difference is full blu-ray hardware acceleration vs partial. During googling I saw someone say that they also had a Toshiba, and the max PC Input display was 1360x768. Going to call toshiba and find out if that is the case with my model.

    Is it possible to go from VGA to HDMI?

    EDIT: So Toshiba customer support wasn't immediately helpful. Had them escalate my issue to get a definite answer on whether the TV can handle 1080p through the VGA port.
     
    Last edited: Aug 25, 2011
  8. guney

    guney Limp Gawd

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    Make sure you're not missing my main point: The graphics adapter being able to output 1080p and higher on a DVI or HDMI output (or display on a built-in screen, in case of laptops) may not imply much about the maximum resolution supported by the RAMDAC through the VGA output. It could be supporting very high resolutions through all of those digital outputs, but only supporting a middling resolution through the analog VGA output. As I explained, the VGA connector is being used more and more rarely these days, and most of those people don't try to obtain resolutions that high over VGA. For that reason, the RAMDAC may have been spec'ed much lower than what the adapter natively supports in digital mode.

    VGA = analog
    HDMI = encrypted digital

    The answer, for all practical purposes, is "no".
     
  9. SJetski71

    SJetski71 [H]ardForum Junkie

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    Guney has the right answers, nail on the head for all of them.

    Hdmi or DVI-toHDMI with your new hdtv, nothing else will work right (a limitation placed on your TV's VGA port, most TV's are like that now).
     
  10. coder_t2

    coder_t2 [H]ard|Gawd

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    Ok I think I understand what your saying now Guney. Thanks for you input, as I don't believe I have an easy fix here if my PC can't handle VGA. Now, here are some specs for my chipset and IGP. Not my computer, but I assume it would have to be similar. It looks like it is saying VGA/Analog should be able to go up to 1920x1080. Am I reading this right?

    http://h18000.www1.hp.com/products/quickspecs/13494_div/13494_div.HTML

    Just control-F "x4500", and click next a few times, and it should bring up specs for the IGP.
     
  11. guney

    guney Limp Gawd

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    Looking through those specs, assuming the integrated graphics adapter (X4500) is really the one you're using, I would read the specs in the same way. Output at 1920x1080 through VGA should be supported (and then some). It actually only says those are the supported "analog" resolutions, and there's an off chance that it might mean only "analog DVI" connections, while the VGA connector is subject to another unspoken limitation, but that would be very sneaky of those specs if that were the case.

    So, yes, in all likelihood, your VGA output should be capable of full HD output through VGA. In addition, when I google the keywords "ramdac 350mhz", I see that all graphics hardware listed with a RAMDAC of that speed is listed as handling up to 2048x1536, which is well above full HD. So, it corroborates that conclusion. There's only this one posting I've come across that says something about 350-MHz RAMDACs being unable to support 16:9 resolutions (which includes 1080p), and that you'd need a 400-MHz RAMDAC for that, but this may have been a quirk of just some nVidia chips back in the day, since everything else that I see seem to indicate the opposite.

    So, the bottom line is that, it doesn't look like the problem is on your computer's side. It might be a limitation of the display to which you're connecting. And that's probably even more problematic for you. Do you have any technical documentation on that display?
     
  12. CrimandEvil

    CrimandEvil Dick with a heart of gold

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    That and the G41 is pretty much gimped for HTPC work. This doesn't surprise me at all.
     
  13. coder_t2

    coder_t2 [H]ard|Gawd

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    I am awaiting a callback from Toshiba tech support today to confirm whether the tv has this limitation. Regardless I need to upgrade my gpu to get hdmi or dvi out, since I can't do anything with the IGP. I have started another thread about switching to one stick of RAM, which is what I need to do to fit a video card on my mobo. Thanks for all the help guney. I am think of a radon 5450 for card.
     
  14. guney

    guney Limp Gawd

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    You're very welcome.

    It's probably safe to say that any current graphics adapter should be able to support 1920x1080 over HDMI or DVI.
     
  15. SJetski71

    SJetski71 [H]ardForum Junkie

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    Edit: never mind, i wasn't following the recent flow of the discussion.
     
    Last edited: Aug 26, 2011
  16. SJetski71

    SJetski71 [H]ardForum Junkie

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    It may not be the model you have but i can already see that the Toshiba 55UX600U LED has a VGA limitation of 1360x768 as per it's user manual.
     
  17. coder_t2

    coder_t2 [H]ard|Gawd

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    Not my model. And my user manual says nothing about a VGA Limitation. But I am pretty sure it is the TV.
     
  18. CrimandEvil

    CrimandEvil Dick with a heart of gold

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    Toshiba does that with a lot of their models.
     
  19. coder_t2

    coder_t2 [H]ard|Gawd

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    Do other brands do it too?
     
  20. SJetski71

    SJetski71 [H]ardForum Junkie

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    Yes, seems like most of them.

    It's a common topic brought up in TV/electronics forums.
     
  21. CrimandEvil

    CrimandEvil Dick with a heart of gold

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    I haven't had any troubles with DVI/HDMI inputs.
     
  22. Kamainae

    Kamainae [H]Lite

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    Toshiba does limit the vga input to 1360*768, also panasonic, sony, and some lg models(mostly european).
     
  23. coder_t2

    coder_t2 [H]ard|Gawd

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    What is the point of limit?
     
  24. scaarbelly

    scaarbelly [H]ardness Supreme

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    I have one sony tv that works great and another that sucks ass to get it to work at 1080p. Sometimes the tv will give refresh rate problems that screw with the resolution.
     
  25. SJetski71

    SJetski71 [H]ardForum Junkie

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    It's been mentioned that it adds another layer of technical support and liability that TV manufacturers do not want (using it as a computer monitor etc).

    Not sure if it's true though.
     
  26. coder_t2

    coder_t2 [H]ard|Gawd

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    Gotcha. Actually saw someone say something similar in a different thread after I posted.
     
  27. SJetski71

    SJetski71 [H]ardForum Junkie

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    Come to think of it, maybe it has something to do with HDCP .... digitally protected content + liability, etc.

    But then analog component outputs on Blu-ray players work around that w/ 1080i.

    Hmmm.
     
  28. CrimandEvil

    CrimandEvil Dick with a heart of gold

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    It goes back to the early 2000's when people were first starting to hook TVs up to their PCs. Back then the drivers sucked for that, you had to custom make your timings and resolutions in the drivers and it was all guess work for some of it. So TV manufactures would make "PC only" inputs and limit them so that the PC couldn't possibly damage the TV. The problem is that now video card drivers are pretty full featured and fully support TVs so there's no point in manufactures doing this other then stupidity.