Z book docking station issues

[Melbourne_Pete]

Hi All, got a couple of issues with my Zbook docking station hoping someone can help.

Work just sent me a new ZBOOK (zbook firefly 15 g7) and I have a workstation setup at home. Nothing crazy, just a laptop connected to a dock that has an extra monitor, keyboard, mouse and ethernet connection via USB 3.0.

The new ZBOOK works fine but when I connect it to the dock it doesn't pick up the extra monitor and ethernet connection though it picks up the mouse and keyboard fine. I tested it another dock I have laying around, also USB 3.0 connection, and same issue.

Is the ZBOOK only compatible with a Thunderbolt USB C Type 3 connection to pick up the extra monitor and ethernet?

[banhien]

@Melbourne_Pete 

The following docks are compatible

With HP Thunderbolt Dock G2

Supports three independent displays

Maximum resolutions

2.5K at 60 Hz (DisplayPort 1) and 2.5K at 60 Hz (DisplayPort 2) and FHD (VGA)

Or

4K at 60 Hz (one DisplayPort port) and 4K at 60 Hz (Type-C output port using a Type-C to DP adapter)

With HP UltraSlim Dock

Supports three independent displays

Maximum resolutions

2.5K at 60 Hz (DisplayPort 1) and 2.5K at 60 Hz (DisplayPort 2) and FHD (VGA)

Regards.

[Max-NZ]

It appears the G2 Dock is not capable of running 2 monitors at 4k @ 60Hz resolution. There're issues with either dock itself (2 docks tested) or the compatibility issue between HP G2 Dock and, in my case, HP ZBook G7. At the moment I'm stuck with connecting second monitor to laptop's HDMI port to get 2 screens to run 4k @ 60Hz each, which is very disappointing and frustrating as the reason behind buying a dock was to have single cable connected to the laptop and have all peripherals connected to the dock.

My issue is described here - Thunderbolt G2 Dock 2 x 4k Monitors - Not Possible / Does Not Work 

[soccer_dan]

Yes, the HP Thunderbolt G2 dock is capable of supporting 2 4k monitors... However, due to the Displayport MST hub used in the dock, you would need to connect 1 4k monitor to one of the DP ports, and connect the 2nd 4k monitor to the usb-c port via a usb-c to DP/HDMI adapter... this is due to the performance available across the Thunderbolt connection and how it is divided for the dock... When we get to TB 4 (eventually) there will be more support for 4k monitors in different configurations

[Max-NZ]

I have followed the solutions you have posted, but unfortunately, as described in my original post, when 2 x 4k monitors are connected in the arrangement you describe (one monitor in DP Port, second monitor in TB3 Port using USBC-DP or USBC-HDMI adaptor) only one monitor gets signal. Whichever monitor is connected to the dock first gets signal, second monitor - NO SIGNAL. When both monitors are connected and I disconnect the one that has got signal, second monitor automatically picks up the signal and starts working fine (this leaving only 1 monitor connected). 

[Max-NZ]

@Soccer_dan,  I had a reply from someone else on my original post. They went through technical explanation and from what I can understand the issue is pretty simple and the Zbook G7 is simply not capable of putting out enough bandwidth over it's TB port to support 2 x 4k@60 displays.

The sad thing is that I spent a few days on WhatsApp with HP going through various scenarios to resolve the issue and, regardless of knowing the exact specs of my laptop (they had PN & SN for my laptop from the start), they couldn't just tell me that their "top of the line" Workstation series laptop is not capable of running 2 x 4k@60 monitors through their own "top of the line" docking station. They sent several replacement docks, made me buy several USBC-DP and USBC-HDMI adaptors to try.... it was a pain...

[soccer_dan]

I am afraid you were not provided correct information. The Zbook Studio (or Create) G7 can output to 2 4k/60Hz monitors over the Tunderbolt G2 dock, one connected to a DP port and the other over the usb-c port with an adapter... However, the potential gotcha is that only a hdmi 2.0 device - and cable - can support 4k/60 hz resolutions ( HDMI - Wikipedia ), so perhaps you may have to go with a usb-c to dp adapter to get the 2nd 4k display to work properly

See attached document with details on connecting multiple monitors to a ZBook mobile workstation

[Max-NZ]

Thanks @Soccer_Dan, it seems like everyone is providing conflicting information. Here's an extract from my last chat with HP Support on WhatsApp. The laptop I have is ZBook Power G7 PN: 2M0E4PA

****

[7:55 am, 22/02/2021] HP Support: rom the specifications we see that thunderbolt port is capable for running 1display at 4k @60 hz. another display can be run via HDMI with 4k @ 60hz Max.
[7:56 am, 22/02/2021] Max: Yes, thanks. My original problem was that when I connect Thunderbolt G2 dock to this laptop it is not capable of running 2 x 4k@60 displays via the dock, but it appears it's a laptop limitation..... is that correct?
[7:57 am, 22/02/2021] HP Support: That is correct Max.

****

I have USB-C to DP and USB-C to HDMI adaptors, both work fine and output in 4k@60Hz to a monitor when connected to the Thunderbolt port on the Dock on it's own (one monitor at a time), so both adaptors are fully capable of running 4k@60 so the device and cables are just fine. They also work in full 4k@60 when connected directly to TB port on the laptop. The problem is that when both monitors are connected to the dock in the recommended arrangement (MON1 to DP port, MON2 to TB port via either USB-c to DP, or USB-C to HDMI adaptor) only 1 monitor receives a signal, whichever monitor is plugged into the dock first will turn on and work in 4k@60 and the second one will display "NO SIGNAL". If a working monitor is unplugged the second monitor will kick in and pick up the signal and will work in 4k@60 but not both simultaneously.

[Max-NZ]

Hi @Soccer_dan, from the document you have provided I can see that ZBook Power G7 is limited to DP1.2 which, according to the same document, is not capable of running 2 x 4k UHD @ 60. I wish HP support staff was more competent to let me know from the start that this is the case (it is HP document they can easily refer to at the end of the day) without dragging me through various troubleshooting steps over the last week, wasting a week of my time and wasting my money by making me buy extra cables and adaptors.

[soccer_dan]

i believe there is misunderstanding on how Thunderbolt works. The native port on the Zbook Power G7 is hdmi... However, the dock is a Thunderbolt connection. The Thunderbolt 3 technology (to simplify) is built around a pci-e x16 path over usb-c. That provides a total of 40Gb/s path to external devices. This bandwidth is split among the ports on the dock. Since the dual DP connections on the dock use a hub coming from a single video output, there is not enough to support 2 4k monitors on those ports. Therefore, a 2nd 4k monitor has to be connected via the usb-c port, with its own bandwidth, separate from the DP ports. Why you need an usb-c adapter for the 2nd high-res display