Bought XPS 8940, should I have waited for XPS 8950? Need advice

If RAM is DDR, and installed as a matched pair(s), it should be running in dual channel mode. 4x2GB means you have four 2-GB modules installed for a total of 8 GB. 

You can run CPU-z (free) and it will show if RAM is running dual or single channel mode. Look on the Memory tab for "Channel #" It will say either "single" or "dual".

Your display should work fine with Win 11. Does your monitor have HDMI or only DVI ? If it has HDMI, which I presume the GTX1650 card has, use that rather than adapters.

NOTE: Video adapters typically only work in one direction, so make sure the one you get is DVI-D(video card)>DVI-I(monitor), or is "bi-directional".

Yes, the 8GB RAM (4x2GB) on my current old system is DDR. I'll check out the CPU-z you mentioned.

The monitor has only DVI-I, so I'll have to use an adapter. Do you think my monitor with DVI-I/DVI-D adapter and Windows 10 driver running on Windows 11 will result in any problems? Or would I be better off springing for a new modern display? I really like my 11 year-old IPS display as it's extremely sturdy and easily swivels in all directions.

Here's the DVI-I/DVI-D adapter I might consider:

Amazon.com: Tripp Lite DVI-I to DVI-D Dual Link Video Cable Adapter (F/M) (P118-000) : Electronics

My Dell monitor is designed to run at its native resolution of 1920x1200 @60hz. Whereas, the Nvidia GeForce GTX 1650 (that I may order with a new PC) is capable of providing 7680x4320 @120 Hz. I'll have to look into modern monitors' typical resolution and the importance of a 120 Hz refresh rate. 

Thanks for the advice on confirming that the adapter has the right direction and gender at each end.

@Leonardo91  - Don't see any reasons why the old monitor won't work with Win 11. You can always order a new one later, if the old one doesn't work, so there's no rush, especially if you like what you have. But the old monitor's "recommended" resolution is probably lower than the video card is capable of providing. 

Confirm the adapter works in the right direction for DVI-D(video card) and DVI-I(monitor) and that it has the right "gender" for the connector at each end for your needs.  

@Leonardo91  That doesn't mean the GTX 1650 card won't provide the native resolution for your monitor. It just means the card is capable of supporting better (higher res) monitors than the one you have now.

A higher res and refresh rate means videos/games can be displayed with more detail and more smoothly on the monitor or TV.

If you're just doing spreadsheets, email, etc, a monitor with higher specs won't add much/anything to your viewing enjoyment. 

I mostly do office type stuff, email, documents, web browsing/social sites, etc. I plan to visit Best Buy to compare new monitors to my 11 year-old IPS display. If the difference is big, I may upgrade the monitor, too.

Thanks for all the great advice!

Lol

Small note for TS on this a bit old revived topic - 8940 supports 11th gen CPUs which does support AVX512 instruction set (12th gen CPU doesn't, well fundamentally it does but I'm quite sure it's disabled on those machines). Therefore really depends on type of workloads you're running on your PC as operational priority, or rather software (if it's optimized to utilize more advanced instruction sets), in those cases you will get materially better performance on 8940 if compared to 8950.