Probook 440 G8 with 3 external monitors. One stuck @1600*900 resolution

[RonanLG]

Dear all,

I've switched from EliteBook 1040 G3 to Probook 440 G8 (2X7F6EA).

I've changed docking station for HP USB-C Dock G5 (5TW10ET).

I'm still using the SAME 3x external monitors.

I've no problem with old 1040, but with this 440 G8 :

Laptop is closed, I'm not using its screen.

1st monitor is 1080p and I'm able to use it @1080p.

Central is 1440p and  I'm able to use it @1440p.

But, 3d monitor is stuck @1600x900 !!

I've test everithing I can :

- Changed all cables

- Change laptop to an another 440 G8/Same model

- Change monitor (other 1080, other 1440p...)

- Upgrading dock Firmware to latest 10.0.13.0

- Laptop BIOS up2date 01.03.02

- BIOS option "Enable High Resolution mode when connected to a USB-C DP alt mode dock"

Always lock @1600*900 😞

Please help.

[banhien]

@RonanLG 

Please use the combination on page 5 of the following document

           https://www8.hp.com/h20195/v2/getpdf.aspx/c04168358

You should be able to connect all 3 monitors. Do you use right cables ?

Regards.

[RonanLG]

Dear @Banhien,

Thanks for your quick response. I haven't find this documents before.

So, to be sure to understand, in my case, I've found that Probook 440 G8 is DP 1.2 (not cool for a brand new 2021 laptop). I've already enabled High Res mode in BIOS.

In the table, I can't find my case (3x Display : 1x 2.5k + 2x FHD, but there is this one up to my case:

(2) 2.5K and (1) FHD, dans there is a "Y" on DP1.2/High Res.

If I undestand, It would be ok no ?

I'm using 2x DP et 1 HDMI on the dock. I've seen "High Res mode DP Alt Mode (DP x4)" on the table. What does x4 means ? There is only two DP ports on my dock.

Regards,

Ronan.

[banhien]

@RonanLG 

I'm using my USB-C Gen 5 dock with 2 monitors on my Elitebook 840 G5 right now.

Unfortunately I only have 5 FHD monitors, I'm not going to buy new higher resolution monitor for my test unless one of them failed to show up. I tested on 4 different machines, 2  have Thunderbolt™ 3 and 2 USB-C 3.1 Gen 2 with 10Gbs, PD and DP 1.4. I can confirm all 3 ports on the dock worked.

From my understanding High res DP Alt Mode (DP x4) means it can use all 4 lanes for video where possible.

Regards.

[RonanLG]

I was wrong on this point : my Probook 440 G8 is not DP 1.2 but 1.4.

I've just installed BIOS Update 01.04.01 witch contains a big lot of fixes and Enhancements:

https://support.hp.com/soar-attachment/621/col101426-ob-274024-1-ob-274024-1_sp114022_releasedoc.htm...

Now I've my 3d monitor than be configured with a 1080p !! 🙂 all my 3 monitors can be on the G5 dock, no more need to connect 3d to HDMI port on laptop.