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Galaxy Flex Book Alpha - HDMI port limitations & USB-C questions

(Topic created: 08-28-2020 06:40 AM)
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userKE7k1ohrFz
Cosmic Ray
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I recenlty purchased a Galaxy Book Flex α 13.3” ( NP730QCJ-K02US  -- i7/12gb/512gb), and I've been surprised and dissapointed by the lack of a proper owners manual with complete specifications.  There's a "user's guide" which contains generic information about the use of the entire Galaxy Book line (13.3", 15", etc) and the specifications on the web are missing a lot of important details.

 

I've been trying to get support for 1440p@60Hz over HDMI (which should work by the HDMI spec) but doesn't seem supported by the hardware.  Installing the Intel driver allows the entry of additional resolutions, but it seems the HDMI port itself is limited. Any resolution/refresh rate higher than 2560x1440@40Hz produces an "exceeds maximum bandwidth" message.  I've tried three different HDMI cables, including 2 that are rated for 4K.   Given that there are plenty of 4K HDMI devices, it seems the HDMI port on this device does not support HDMI 1.4.

I've considered buying a USB-C display adapter, but without a list of supported alternate modes on the USB-C port, I don't know what version of display port is supported.

Does a comprehensive specifications document exist for this laptop?  The brief list of specifications on the website is really insufficient.

EDIT: I have applied the November 2020 BIOS update and 1440p@60Hz over HDMI now works in Windows 10.  A comprehensive, detailed specifications document  would still be appreciated if anyone has one to share.

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userKE7k1ohrFz
Cosmic Ray
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Did they indicate if the USB-C port supports DisplayPort as an alt mode?  My understanding from here (https://www.cablechick.com.au/blog/definitive-guide-to-usb-c-alternate-modes/#:~:text=%20At%20the%20...

Is that there may be no USB-C HDMI alt mode devices, so I'm hopeful that the alpha supports DisplayPort. 

 

Should I start a new thread for the specific resolution support question?  My resolution is within the bandwidth range for HDMI 1.4b, and the Intel forums seem to indicate that when a custom resolution does not work it is because the device bios has in some way prevented it. 

 

Thank you again for your help!

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userKE7k1ohrFz
Cosmic Ray
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You are correct about the HDMI port. The resolution issue must be a Windows driver bug and I will start a new thread. 

I have booted Linux and in Linux the monitor is working at 2560x1440@60Hz over HDMI with zero fuss. 

 

So do we believe that the USB-C port does not support thunderbolt or DisplayPort?  

EDIT: There is a display port device supported through the USB-C port.  I can see it in linux:

[    14.062] (II) modeset(0): Output eDP-1 connected
[    14.062] (II) modeset(0): Output HDMI-1 connected
[    14.062] (II) modeset(0): Output DP-1 disconnected

eDP-1 is the internal LCD; HDMI-1 is obvious, DP-1 must be the USB-C displayport controller.

 

Here are the stats I could learn through xrandr (I have no device connected to the USB-C display port device):

DP-1 disconnected (normal left inverted right x axis y axis)
	Identifier: 0x44
	Timestamp:  18228
	Subpixel:   unknown
	Clones:    
	CRTCs:      0 1 2
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000
	           filter: 
	Content Protection: Undesired 
		supported: Undesired, Desired, Enabled
	max bpc: 12 
		range: (6, 12)
	Broadcast RGB: Automatic 
		supported: Automatic, Full, Limited 16:235
	audio: auto 
		supported: force-dvi, off, auto, on
	link-status: Good 
		supported: Good, Bad
	CONNECTOR_ID: 100 
		supported: 100
	non-desktop: 0 
		range: (0, 1)

 

UPDATE: I contacted Intel and they blamed the Samsung BIOS.  Sure enough, after applying the Nov 2020 BIOS update, 1440p@60Hz over HDMI is working for me in Windows now, too.  Seems the issue was the Samsung firmware.  I'm just happy to have it resolved.

userUWU9L9d2ie
Constellation
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I use an ASUS USB-C monitor with my Galaxy Book Flex, connected via a Thunderbolt port.

 

I use an Inateck USB-C hub to provide split-power AC to both devices -- I expect if I had a monitor with a battery that would be unneeded & the monitor could be wired straight into the laptop, as I already do with my older Samsung Chromebooks.

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userKE7k1ohrFz
Cosmic Ray
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The flex and the alpha are fairly different, the alpha does not support USB-C charging. 

 

The USB-C port on the alpha does support DisplayPort over HDMI.  I gave up and bought a USB-C hub with video and the HDMI connector on that hub does provide the correct resolution and refresh rate. 

 

Seems silly that the built in HDMI port is less useful than the one that came with a $15 USB-C hub but there seems to be no interest from Samsung in updating the bios or drivers for my model to address this.  I guess that's what I get for buying the cheapest of the Samsung Flex book lineup. 

 

 

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userKE7k1ohrFz
Cosmic Ray
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Just to close the loop on the HDMI resolution issues, I contacted Intel and they blamed the Samsung BIOS.  Sure enough, after applying the Nov 2020 BIOS update from Samsung, finally 1440p@60Hz over HDMI is working for me in Windows too. 

Seems the issue was the Samsung firmware and  I'm happy to have it resolved.

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