some of the systems on the Dell sight show the intel XE graphics as being shared ram... and the tech specs showing things lik 8gb + 4 gb, 12gb + 4 gb
DO i assume the lower stated value of ram is for the XE graphics?
Sounds weird. AFAIK Iris XE doesn't have designated VRAM, so its sharing system memory like integrated graphics usually does. I looked at the Dell website and couldnt find what youre talking about here. I havent used integrated graphics in a long time but seem to remember you could set the amount of RAM dedictated to VRAM in the BIOS somewhere. Maybe Iris demands 4GB at all times.
IS it better then the inegrated vega graphics on AMD integrated processors?
IS the intel XE with an apparent 4gb of dedicated RAM the equivalent to an nvidia RTX 30xx series graphics card with 4 gb of onboard RAM?
Iris XE wont be anywhere close to the performance of any RTX card, not even the older 2000 or even GTX 1000 series, except maybe the very low end GT1010 they just released or maybe a GT 1030 DDR4. Even if it had 16GB VRAM available it wouldnt have the power to use it.
Scroll down to the bottom of the table to find the fastest desktop Intel Iris to date according to Toms Hardware hierarchy. The Vega 7 and 8 is slightly better in their tests. There are older versions of Vega used with older Ryzen CPU's that may be worse or better depending on which models...
With laptops you have to be a bit careful, because the same chip and graphics solution can perform better or worse depending on the cooling of the laptop or the amount of power the manufacturer lets it use. Better to look up reviews for the specific laptop you are considering rather than the CPU or graphics itself.