I'm struggling a bit with finding the answer so i hope some readers out there can help me out.
At work they made a plan to provide several users dual 4K@60hz setups. (Don't ask me why, it's what they decided so "it's happening" (is what my boss said)). To Sum up a long background story, our Dell sales person provided us with a Dell Latitude 5500 (i7-8665U with Intel UHD 620 Graphics) with a Dell Thunderbolt Dock WD18TB and the message that this supports dual 4K.(installed with the latest video drivers from Dell)
After some testing, i can't even get dual 4K on this setup, let alone @60hz.
From what i can find, i think this GPU doesn't support that. Intel's website doesn't list the specific versions of Displayport (only HDMI 1.4). But a few sites have stated that it is Displayport 1.2. If that is the case, from my understanding, it would not be possible to support dual 4K because there is simply not enough bandwidth to support it.
If i have dual 4K@60hz, that would be the same as saying: 7680x2160@60hz correct?
If i look at https://k.kramerav.com/support/bwcalculator.asp and calculate the bandwidth and compare that with the maximum bandwidth provided by DP 1.2 (https://en.wikipedia.org/wiki/DisplayPort#Cables_and_connectors), taking into account only 80% is designated for video. A 4K (3840x2160@60hz) resolution would fit. The 7680x2160@60hz would not. But it wouldn't fit in DP 1.4 either if the information is correct.
If i look at https://multimonitorcomputer.com/solved/displayport-high-bit-rate-2-hbr2.php my assessment would be correct, DP 1.2 can only support a single 4K@60hz and not more.
And if i look at https://multimonitorcomputer.com/solved/displayport-high-bit-rate-3-hbr3.php it would seem that it should support 7680x2160@60hz, but that is not what the bandwidth calculator suggest.
I am assuming allot of things and taking them with a grain of salt. Probably because i feel like either i misunderstand something or lack some information in how this all works. So i came here i hopes somebody with more knowledge could help me understand it.
How can i find out whether the device supports dual 4K@60hz
If it doesn't, how can i find out what does support this?