High frequency ram (2300MHz+) and CPUs

[Cobez]

Hello!

 

I've been browsing computer parts recently have noticed that there is a lot of high frequency RAM on the market (ie, 2400/2600/3000/3200MHz etc..). I know that motherboards can support these speeds if they overclock, but the latest CPU's (i7 6700k/6700) are only rated for maximum DDR4 2133MHz (link).

 

- Am I reading these CPU specs correctly? (ie should I be doubling the frequencies because its 'DDR' double data rate)

- What is the highest RAM frequency the i7 6700k can support (k indicates that you can overclock it correct?)

- What is the highest RAM frequency the i7 6700 can support?

 

Cheers,

Cobez 

[Flesky015]

2133mhz is the default speed of memory ddr4 like 1600 is for ddr3, on Z chipset motherboards you can oc the memory either by xmp or manual overclocking

the i7 6700 can support any but you need z chipsets and to enable xmp/oc the memory.

[ZetZet]

just buy the highest speed for the money. 3000mhz or something is good value. you need a z series mobo to use faster memory though.

[SaladFingers]

Yeah CPUs don't officially support more than 2133mhz out of the box, but they all work just fine with an XMP profile (even without one actually) as long as the motherboard itself supports it. To be honest, your RAM frequency is one of the most trivial things, the real world difference is almost non-existent. Get the best value you can but don't overspend just to get the highest freqs, it's not worth it.

[Cobez]

Will the i7 6700 support higher frequency RAM? Even though it is not unlocked?

[SaladFingers]

5 minutes ago, Cobez said:

Will the i7 6700 support higher frequency RAM? Even though it is not unlocked?

Yes, locked or unlocked isn't about the RAM, it's about the CPU itself. These RAM sticks get their high frequencies using XMP 2.0 profiles, which most if not all current motherboards for that socket do support. It really is just a switch in the BIOS to turn it on, doesn't matter if the CPU itself can be overclocked or not.

[porina]

To keep things mostly simple, almost everyone uses the marketing speed rating, which is already doubled. From memory the only place I see the non-doubled value is in CPU-Z.

 

Since high speed ram is basically an overclock, results are not 100% guaranteed. Early on in Skylake era when bios for mobos were not as mature, I had difficultly getting my system 100% stable. I run workloads comparable to Prime95 24/7 and would get a detected error about once a week. Later bios releases combined with better ram modules seems to have made this less of a problem now.

 

As for what speeds are supported, hard to say. For fun I tried a ram only overclock. With Corsair LPX something or other modules rated at 3000, I could boot at 3600 although never got it 100% stable.

 

In my use I do have and need high speed ram, but as others will no doubt be keen to point out for most software it makes little or no difference. If looking to build a system, I wouldn't pay disproportionately more for higher speed ram. Around 3000 rated is still a decent boost above standard yet pretty safe.

 

On ram OC with non-OC mobo, there may be a limitation on the chipset. I'm not 100% sure about this, but believe you either need an OC mobo (like Z chipset) or, Asrock do offer some lower cost mobos they hacked higher speed ram support into but it relies on having certain modules.

 

http://www.asrock.com/news/index.asp?id=3043