Originally Posted by shilka
Not all 5820K CPU´s can work with RAM faster then 2800 MHz so there is a risk that if you get a kit faster that it might not work.
Its only some of them and not all of them so its up to you if you want to spend money on something that might or might not work.
2666 MHz will work for sure.
3200 is stronger than 2666 when using the 100:133 memory strap. 24x is the strongest ratio somebody can go with this platform while maintaining CPU strap 100 in order to keep the benefits of adaptive voltage. 2666 can do quite good in conjunction with CPU strap 100 but it requires stronger binned DIMMs in order to avoid experiencing drops during POST if the user doesn't want to do some further tinkering, other than switching CPU strap and BCLK to 100 and manually entering the timings. XMP for anything 2666 and up sets CPU strap to 125, sets VCCSA to an insane amount that is definitely not needed when not pushing extreme overclocks as well as disables the ability of using adaptive voltage.
Considering plug and play only, someone would go the way of XMP anyway and that wouldn't matter in the end since even a 3200 rated kit would preset CPU strap to 125 with XMP too.
XMP is an auto preset that doesn't have optimal settings for your system by any means. It could even make the CPU IMC complain by setting a VCCSA value that it absolutely hates in the first place.
Generally speaking single sided 2666 kits are able to reach 3200Mhz but without guarantee of better performance when the kit is tightened as much as possible while running at 2666. Both of these scenarios require the user to overclock though.
2800 and 3000 are not yielding good results along with the 100 strap successfully. Most of the times it requires some work just to get them going with this strap anyway.
Originally Posted by SoccerNinja
Do you think you can just direct me to the best ram for a gamer/video editor in the $100-$200 range. For the specific motherboard and a 5820k.
It all comes down to the memory capacity you want to run in the end and if you want to keep adaptive voltage. If you don't want much hassle with what's stated above and you are not messing with the BIOS, I suggest you should get a 2400 kit at the capacity that suits you. Core clock and even cache clock will give you higher benefits than faster RAM by far(since the later also influences memory bandwidth vastly). If you said you wanted to get the best you can get for this platform I would say aim for 3200 either by getting a kit that can already do that or by getting a lower rated kit and hoping to get it to 3200 using the 100 strap.