Dell Latitude 7480 HDMI Output and slowness issues

[Connoisseur]

I recently got a new Latitude 7480 from my office. Performance has been... okay but had a couple of issues and was wondering if someone could help diagnose:
1) CPU Utilization - I find that the CPU spins up regularly for fairly mundane tasks which didn't cause a hiccup in my old laptop. For example, I had 3-4 excel spreadsheets open (no macros or anything running in the background) and CPU utilization for Excel spiked to >50% sustained. It's also happened to me with Google Chrome and Edge even if I'm not on websites with video. This obviously causes the CPU Fan to spin up which is fairly annoying. I've disabled Windows indexer and as many startup apps as I could (it's a bit locked down since it's a business machine) with minor success but I still get a lot of CPU utilization spikes.
2) HDMI Output Issues - At home, I connect the laptop to my Dell U2718Q 4k monitor via HDMI. Regardless of the resolution I set for the monitor (I've tried 1080p to 4k and all combinations in between), the speed of navigation is significantly slower than when I'm just using the laptop screen. The mouse cursor and keyboard have noticeable input lag and switching between windows and general navigation also feel much slower. I'm not sure why this is the case. The output looks clear otherwise (no graininess or blurry text) which may indicate some driver issues.

Any suggestions on these issues would be greatly appreciated. Otherwise, I have to take it back to IT to see if they can replace it for me.

 

[VirtualLarry]

It's possible that that laptop has both an iGPU and a dGPU, and the internal laptop screen is wired to the iGPU, but the HDMI output is wired to the dGPU. (This is common.)

Therefore, it would need to use software / driver tricks, to constantly copy the iGPU's buffer into the dGPU's VRAM, so that the external display gets updated.

 

[mynameisphunk]

I believe that the HDMI port on the 7480 is HDMI 1.4, and therefore will only work at 30hz (might actually only be 24hz). You'll be able to check the available refresh rates in the advanced display options in the Intel driver. This will be a very noticeable input lag.

I'm frustrated with this as well, as it means unless we opt for Thunderbolt-capable 7480s (an option, only available on certain configs at higher cost) as our standard, there is no way to get 4K60 to an external display out of this laptop if you have a USB-C dock connected. This affects exactly one person in the company right now (me, I bought my own TV to bring in and use as a monitor), but long term it is an annoying limitation of a brand new business ultrabook.

To get 4K60 to your monitor, you can get a USB-C adapter to HDMI 2.0 inexpensively that should work (I haven't tested personally) - this is just one example:

https://www.amazon.com/Plugable-Chromebook-Thunderbolt-Supports-3840x2160/dp/B01FIVSC6Y

 

[lapamato]

I had general slowness on my 7480 (Windows 11) and finally found the reason. The issue was solved by disabling Windows’ "Virtual Machine Platform" -feature. Before that I disabled Hyper-V and Memory integrity check, which may or may not affect the performance. I hope this comment helps someone, even though the thread is old