XPS 8930 Incorrect Memory Speed in BIOS

You didn't state the model of your memory but I am willing to bet the the specs of your memory state that the SPD speed is 2133 MHz and that the tested speed is 2666 MHz. The Dell BIOS uses the SPD speed and does not have a way of adjusting the memory speed. The BIOS does not read the XMP data. If you want your memory to run at 2666 MHz you will have to buy memory with a SPD speed of 2666 MHz.

Well I just learned something. Thank you so much for shedding light on this subject! I thought the advertised speed is what you could expect. But you are right, when I went to the manufacture's site there they state the SPD is 2133. Been buying Dell computers my entire life and this is the first time I was not able to get the full potential out of my add on components. If I would have purchased a model with the i7-8700"K" would that BIOS allow XMP? Feeling like a made a bad choice in this computer now.

Searching I can only find one RAM module that has SPD 2666 (Kingston HyperX Fury). Not sure if I should try and return G.Skill and buy the Kingston. Or return the XPS 8930.

The stock RAM although running at 2666 had a CL of 19. The G.Skill I got is running at 2133 but a CL of 15. I am guessing those mostly balance each other out performance wise. But I imagine the Kingston running at 2666 with CL 16 would be a good performance boost over both (I am guessing around 15%)? But would that performance boost in memory contribute the same to overall system performance?

I do not game, but do run many concurrent apps like CAD, Photoshop, Office, compilers, etc. And I have the GTX 1060 in it as well (and an SSD).

Again, any help/advice would be greatly appreciated. Not sure what to do as I am hoping to have this new setup for a few years. Thank you!

Buying the XPS 8930 with the i7-8700K would not help since the  BIOS is the same in all 8930s.

The speed difference in actual use between 2133 MHz and 2666 MHz is not all that noticeable (probably no real world difference), the main thing is the additional memory you now have. You did not mention any additional cost difference but again it is probably not worth it. At this point I would spend the extra money on a bigger SSD for additional storage especially with SSD prices coming down.

Ok thanks. I guess I will stick with the memory I purchased. Seems to respond as fast as the stock memory so at least I am not going backwards. Thanks again.