Sorry, you need to enable JavaScript to visit this website.

Information about supported resolutions and refresh rates

1 post / 0 new
Jeroen van den Bos's picture
Starter
Jeroen van den Bos

Jan 27, 2015 - 03:37am

  • Hi,

    I'm looking at getting an Intel NUC in combination with a high resolution monitor and want to run Linux (Ubuntu) on it. It's quite difficult to discover what resolutions and refresh rates are supported by the i915 driver for each GPU.

    Some points:

    1. I understand that for the highest resolutions, it's best to use a DisplayPort connector.
    2. NUC product specs are pretty vague -- even the newly announced 5th generation models have descriptions like "supports 4k", while omitting info on whether this is in 30hz, 60hz, or?
    3. The technical product documentation is confusing at best, for example:
      1. The "4th gen core family desktop datasheet" seems to suggest that 4k@60hz is doable on a 4th gen NUC (p. 35, table 9).
      2. The "technical product specifications" for the top-range 4th gen NUCs specifically denies it (p. 22, section 1.5.1.4).
    4. Furthermore, using tools such as xrandr, cvt and gtf seems to imply that the supported refresh rates are related to the clockspeed of the GPU, such as discussed in this bug: https://bugs.freedesktop.org/show_bug.cgi?id=85621, but the documentation for Intel GPUs often have specs such as "clockspeed: 300-1100MHz". So if a refresh rate requires 450MHz, does this mean it's supported?

    In general my question is: given an Intel CPU/GPU combination and a desired resolution/resfresh rate, what's the best way to discover whether it will work (without trying it out :))?

    Thanks for any help! (PS. I tried adding links for the documents mentioned in 3a/b, but they couldn't get past the spam filter.)

    Edit: In the meantime, I have discovered some relevant documentation very close by: the Documentation-link on the left! If I choose a platform there (for example, "2013 Intel Core Processor Family") I can then select "HSW - Volume 11a: Display", which contains a lot of information (starting on page 147).

    The problem there is that the information is quite cryptic: I would have to know realistic values for primary plane, sprite plane, panel fitting and down scale amount... But maybe the table on page 154 shows a baseline to derive values from?

    Jan 27, 2015 - 03:37am
  • Interesting question - I don't know the answer, to be honest, but if I were you I'd try the #intel-gfx channel on freenode irc - some of the developers hang out there and they're the mostl likely people to know.

    Feb 02, 2015 - 04:22pm