XPS 8940, new, CPU performance is very poor

I'm sure this will be a support case as well but just wanted to get the general consensus on what I can expect. Since I got the XPS 8940 I've noticed worse performance than I expected from the i7-11700 processor.

When I benchmark it, it consistently falls about 30% short of the expected scores. For example in the Time Spy benchmark in 3DMark it scores 5700 for the CPU test, whereas an 11700 generally should score somewhere around 10-11k.

The CPU is thermal throttling non-stop as soon as it's under any load. I'm aware that the stock cooler in this machine is not great and could be upgraded, but I don't want to invest more time and money into a system that may be a lemon.

Any advice?

Thanks!