[GTALUG] PC build recommendation

[Alex Volkov]

Hi Hugh,

Thank you for your comments, see my replies below.

On 02/27/18 15:34, D. Hugh Redelmeier via talk wrote:
> | From: Alex Volkov via talk <talk at gtalug.org>
>
> | On 02/27/18 11:32, Lennart Sorensen wrote:
>
> | > Displayport is much much more versatile and futureproof.  And supports
> | > daisy chaining monitors and higher resolution than HDMI.  Also trivially
> | > adapts to DVI, HDMI, etc.  I would not consider buying anything without
> | > at least one displayport.  Especially since the HDMI on the AM4 boards
> | > is 1.4 not 2.0, and hence limited to 4k @ 30Hz, not 60Hz.  At least
> | > intel based boards tend to be HDMI 2.0 these days.
>
> | All the cheap screens I have either have HDMI or DVI, so I thought to have a
> | simple common display output that would give me the same gamma settings across
> | all of the screens.
>
> Really?  I thought that gamma needed to be adjusted for each screen
> (if one cared).
What is the procedure for calibration? is there a way to do it in Linux? 
Do I need a special device for that?

I heard 'gamma calibration' being mentioned but I have no idea about how 
it's done.

>
> | Displayport is more versatile, and there seem to exist
> | adapters out there that go from DisplayPort to Dual HDMI or Dual DVI, the
> | question is would this kind of set up work with X11, KDE on open source
> | drivers with Radeon Vega chip?
>
> What do you mean by "Dual"?
I mean a some sort of a splitter driving two monitors.
 From reading replies and doing a bit of research, It looks like 
DisplayPort has the feature of carrying several video streams and 
supports that kind of splitting but not HDMI; Even HDMI 2.0 seems to 
have the capability of carrying 2 channels per physical port it's 
bandwidth is limited to 18Gbps whereas DP bandwidth is 32Gbps.
>
> There is a concept in DVI-D of "Dual Link".  That is needed for
> resolutions above 1920x1200 at 60.  It's not too well known, but
> important to me (my previous monitor was 2560x1600 and only accepted
> dual-link DVI input).  DP -> Dual Link DVI requires an active
> converter (usually $~100 but I found some cheap on Kijiji).
>
> There is also a concept of Dual Link in HDMI but I don't imagine any
> devices ever supported it.  It requires a different connector and
> cable.
>
> If you mean DP to two separate video connectors, Lennart addressed
> that.
>
> Note: DVI is a dead end.  The standard is frozen in time.
I just need HDMI to DVI converters for some rather old 1080p monitors 
that are still working perfectly fine.

>
> A cable with DP on one end and DVI-D or HDMI on the other is under $10
> from Prime Cables (plus shipping):
> <https://www.primecables.ca/p-331688-cab-fl-445-914-primecables-displayport-to-hdmi-adapter-cable-mm-3ft-black>
>
> To go to HDMI 2.0 is more, I think:
> <https://www.primecables.ca/p-362078-cab-12781-displayport-12a-to-4k-hdmi-active-adapter-black-monoprice>
> Do check the details.
>
> | I'm more concerned with what kind of hardware I can reliably use today that
> | trying to future proof it and then spending weeks messing with the settings.
>
> Cheap UltraHD TVs require HDMI 2.0.  They are so appealing, and
> getting more so.  Make sure you can support HDMI 2.0.  You can buy one
> NOW for as low as $300.  Since the screen has the same number of pixels
> as four FullHD monitors, that's pretty hard to ignore.
>
> UltraHD TVs are cheaper than UltraHD monitors.  TVs don't usually have
> DP inputs but UltraHD monitors do.  TVs tend to have chroma
The board Asrock AB350 mini ITX, or more precisely Ryzen 2400G supports 
HDMI 2.0, so in this configuration it should be possible to drive two 4K 
screens at 60Hz.

https://smallformfactor.net/forum/threads/raven-ridge-hdmi-2-0-compatibility-1st-gen-am4-motherboard-test-request-megathread.6709/page-3#post-86831

I wonder if it's possible to connect more than two screens with two HDMI 
ports? (This question is more theoretical than anything else).

Lennart mentioned MSI B350I ITX motherboard that has DP and HDMI. I 
looked at it for a bit, compared to ASRock the following put it at 
disadvantage:

* It's not yet available in stores
* Ethernet chip is not Intel
* Reviews show that MSI BIOS is consistently worse then any other boards
* Really obnoxious naming (They even managed to call something more 
obnoxious than fatal1ty)

> sub-sampling which I can live with but you might not want to.
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