Question External display lag with thunderbolt

[Nighthawk117]

Hi guys,

Just wanted to get your thoughts as not really finding any good answers on google. I have a Lenovo 720S 14" laptop that I connect to an external display, mouse and keyboard via an HP Thunderbolt Dock 120W G2. I find the external display to not be as responsive as the internal display. For example if I play Halo Reach on the internal display, it runs at 60 FPS and it's very smooth. If I play it while plugged into the dock there's very noticeable lag and I've also noticed it struggles to maintain a 60FPS frame rate. There are regular drops down into the low 40's.

I'm just curious why this is, is it because Thunderbolt is wired to the chipset and not directly to the GPU? The Thunderbolt 3 port on my laptop is a 2 lane solution so 20 Gbps not the full 40 Gbps. However I'm not using an eGPU so I didn't expect this to matter.

Thanks

 

[Lutfij]

Can you check and see if the dock you're working with has any firmware updates pending;
https://support.hp.com/us-en/drivers/selfservice/hp-thunderbolt-dock/20075223/model/20075224
?

External panels resolution? Laptop panel's resolution?

 

[Nighthawk117]

Can you check and see if the dock you're working with has any firmware updates pending;
https://support.hp.com/us-en/drivers/selfservice/hp-thunderbolt-dock/20075223/model/20075224
?

External panels resolution? Laptop panel's resolution?

Laptop display is 1080p, external monitor is 1440p. When I'm using the external monitor I'm only using that display, nothing is displayed on the laptop screen. Performance is the same when using a 1080p monitor.

It's much more playable at 720p but still not quite as good as on the laptop display at 1080. I've updated the firmware but no improvement.