Always check the BIOS for what speed the RAM is set to. If the label says 2666 for example, with a little bad luck, it might be running at slower than that speed. Check if there's a setting for that. OEM builds should have it run at the advertised speed, tho. Otherwise, false advertisement. Which means a law suit
Intel has XMP (extreme memory profile), for example, that overclocks the RAM automatically. AMD does not have that, AFAIK, but some mobo makers came up with their own tricks similar to XMP. Otherwise, do it manually and good luck with that.
I have been trying to get into the BIOS to check the RAM speed but, even though I have tried 'restarting' my pc and 'shutting down', when I boot it up again I do not get the options in the bottom right hand corner to press F12 or whatever to enable me to get in.
Does anyone know why please?