Inspiron 13-7578, Dual U2718Q setup

@Cboud  there’s no such thing as an Inspiron 13 7578. The “5” in that model number would indicate a 15” display model. An Inspiron 13 would have a 3 there, such as the 7378.

Anyway, the only way to run dual 4K 60 Hz displays from that system on a single connection would be a DisplayLink dock (not to be confused with DisplayPORT) like the Dell D6000. The issue there is that DisplayLink has some pretty serious drawbacks for certain use cases that I wrote about in the thread linked later in this post, specifically the post in that thread marked as the answer.

The only OTHER way to run dual 4K 60 Hz displays from a single connection to most systems is with Thunderbolt 3, but if you have an Inspiron 13 7378, you don’t have that. In fact, it appears that the 7378 doesn’t even have a regular video-capable USB-C port. The specs suggest its USB-C port is data-only, which is fine for DisplayLink because of how it works, but it means you don’t have a native GPU output there. If you did, you could run one 4K 60 Hz display from there with the right cable and no DisplayLink drawbacks. But even then, the only other output on that system is HDMI, but since the specs don’t specifically say HDMI 2.0, it’s probably HDMI 1.4, which is only enough for QHD 60 Hz or 4K 30 Hz. So you’d still be stuck trying to run two 4K 60 Hz displays.

Honestly though, on a 27” display, for reasons relating to pixel density and the reality that many Windows apps still don’t handle display scaling well, there’s still a strong case that QHD resolution provides a better experience than 4K. But even if you got QHD displays, you’d have to use DisplayLink for at least one of your displays because the HDMI output would only cover one QHD display.

If after reading the thread I linked below you decide DisplayLink won’t be acceptable to you, I’d strongly recommend getting a laptop that has a Thunderbolt 3 port, like an XPS 13, and then a Thunderbolt dock like the WD19TB.

Link about DisplayLink’s drawbacks: https://www.dell.com/community/Alienware/Docking-Station-D6000-Very-Bad-Video-performance-for-gaming/td-p/6193369

@Clintlgm  a WD15 doesn’t support enough bandwidth for even a single 4K display at 60 Hz, never mind two.