Question about Corsair Vengeance LPX

Yes, they go in. There are various versions of the PC, all of which have 2x8GB 2666s in them with 2 free slots (otherwise open the cover and look inside). This means you can either replace the existing RAM in the exact same slots, activate XMP in the BIOS and then have a fast 32GB. Or you can simply add the new RAM (total 48GB) and change nothing in the BIOS. It's a shame that the 3200s will probably only run at 2666 because of the existing RAM, but it's easier. In this case, you could also use somewhat cheaper RAM and save 20Fr, on the other hand, I find Corsair Vengenace very good (quality).