Which memory speed with Kaby Lake?

[fwerff 70]

Hope someone can educate me here.
I'm working on getting the parts for my new system. It will be either an i5-7600k or an i7-7700k, depending on the deal I can get.
As for memory I'm looking at either 16GB or 32Gb (anticipating for a 64bit P3D) also depending on the price.
Now what puzzles me is what memory clockspeed to get. I'm leaning towards a set of G.Skill RipJaws or Trident Zs. I can buy them in a large variety of clockspeeds, basically from 2400MHz up to somewhere in the neighbourhood of 4GHz.
From going through some threads in this forum, I see most of you end up buying something like 3000, 3200 or 3400MHz.
But based on what?
There's quite a price difference between 2400MHz and 3400MHz, so I rather do not spend money on potential I do not need.
Then there's also the CAS Latency. I always learned that you better have a low CL with a bit lower clockspeed then a higher CL with a high clockspeed.

I would greatly appreciate if someone can explain to me how this all ties together and how I can make the best choice for the best cost.

Please note, the system will be build around an MSI Z270 Gaming M5 motherboard and I'm planning to do some overclocking depending how far I can get with reasonable temps (will have either Corsair H115i or NZXT Kraken X61/X62 cooler).

Thanks in advance.

Cheers,

Frank

 

 

[TechguyMaxC 516]

Memory speed makes a difference for Flight Sim, especially in your minimum frame rates.  You can see this in the FSXMark thread.  Buy the fastest 16GB kit you can afford.  32GB is useless at the present point in time, even with 64-bit X-Plane (there just isn't enough data to fill up that amount of RAM yet).  Things will change as flight simulators and their add-ons evolve.  Eventually we may see usefulness for more than 16GB of RAM, but you don't need it today so why spend the money?  You can always add more memory later.  DDR4 isn't going to disappear any time soon.

[westman 257]

If you have a 7700k clocked 4.5ghz you want some  more you Clock the cpu to 5ghz men 2400mhz.

Another approach change  mems  in fsx p3d you get approx 0.8% /100mhz gain,  with 3600mhz mems you have the same performance åt 4.5ghz as 5ghz with 2400mhz.

Saab340 have done lot of tests on both dd3 and ddr4 , search on this forum you have the answer 

[Dexter1979 101]

The faster the better... but in my case I use a Asus Maximus IX Formula and for some reason 32gb of 4133mhz mem can only be used up to 3600mhz... I think is a bios issue.... First visit a couple of forums and do a little research before buying...

[westman 257]

Think its Only the Apex  that do  that easy, mobos with support 4sticks have problem over 3800mhz.

Therfore i dont recomend speeds  over 3600mhz, i have a Apex mobo and 4266mhz mems work.

[fghdgdfdfgfgf 111]

unintentional post

[Gary A 8]

I'm not an expert but this is what I considered based on research of various forums I purchased 3000mhz.  However, I have read that with certain MB's and certain processor and whether or not you intend to clock the FSB, that 3200Mhz can be more stable.  I have had zero issues with my 3000Mhz but I am the type to nip any potential problems in the bud, so I would recommend 3200Mhz for several reasons:

3200 because:

1. It shuts up many of the internet guru's debate 3000 vs 3200 etc etc

2. 3200 is a bigger number than 3000 and we all know that bigger is better; right? At the least better inflation of ego and compensation for psychological inadequacies at a minimum.  You will sleep better at night with 3200.

3. Nobody is going to call you a fool for 3200 say versus 3400 or more, 3200 is a nice median.

4. Thwart any potential strap issues if any exist. I doubt strap is an issue but hey, when I read a post by an ASUS Tech regarding it, I have to listen.

Why I bought 3000:

a. Testing results of various memory speeds by reputable internet sources indicated that 3000Mhz was best performance versus costs.

b. CAS 15-3000 is same latency as CAS 16-3200

c. I read the ASUS post after I bought 3000

Side Notes:    1. New Integrated memory controller (IMC) are not as sensitive to CAS timings as in previous CPU's therefore one should accept speed over lower CAS latency for performance. 2. anything over your CPU rating (2400Mhz in this case w/DDR4) is considered  overclocking. 3. Perceivable difference 3000Mhz vs 3200Mhz =zero

Buy 3200Mhz and don't look back, however any 2400 and up will serve you well based on how much money you want to spend.  If you Google Strap, latency, memory frequency, memory controller etc there is a host of information on specifics on how all that works and ties.

 

 

 

 

[westman 257]

3200mhz c14 is not bad or if you like to step up 3600mhz c15.

Sim FSX or P3D scale on memspeed, 3000mhz c15 is ok if you not intend to OC.

Its not the same rules for flightsim as general gaming, 

Can  you give more info sidenote 1 , prev  cpus , is it ddr4 haswell_e , Skylake to KabyLake?

 

[Dexter1979 101]

I've managed to get the 32gb (8x4) to 3866Mhz using 1.4v dram voltage with 18-19-19-39 timings... I think with 1.45v might reach 4000Mhz...