Question: Choosing memory speed when not over-clocking

haertig · 01-26-2018, 04:10 PM

I have a question on memory speeds. For a computer that I do not plan to overclock, does that mean that I should forget about any of the speeds listed below that have "(O.C.)" after them? Limiting me to 2133? Or is memory speed not dependent on CPU clock speed and can be set independently? I value stability and longevity over speed. So which speed should I go with? Seems like the 2133 and 2400 are reasonably priced, but once you get above that, prices start to skyrocket. And the "approved memory" list of vendors/products starts to shrink too. I want to stick with decent quality memory that is commonly available (in case I want to upgrade, I'd like to match brand/line) - Corsair Vengeance, Crucial Ballistic, or Kingston Hyper most likely (are those decent choices?) Any specific recommendations (I'm looking for 2x8Gb pair)? CPU will be either an i5-8600K or i5-8400, if that matters.

Motherboard specs:

Code:

4 x DIMM, Max. 64GB,
DDR4 4000(O.C.)/3866(O.C.)/3733(O.C.)/3600(O.C.)/3466(O.C.)/3400(O.C.)/3333(O.C.)/3300(O.C.)/3200(O.C.)/3000(O.C.)/2800(O.C.)/2666(O.C.)/2400(O.C.)/2133 MHz
Non-ECC, Un-buffered Memory 
Dual Channel Memory Architecture 
Supports Intel® Extreme Memory Profile (XMP)

Thanks!

keefaz · 01-26-2018, 08:48 PM

Link to motherboard website? Or at least model name?

haertig · 01-26-2018, 09:02 PM

ASUS Prime Z370-A

https://www.asus.com/us/Motherboards...70-A/overview/

https://www.asus.com/us/Motherboards...pecifications/

p.s. - This build will be running on Windows 10. I know, yeuch! But it will be a trading computer, and all that software is pretty much 100% Windows.

jefro · 01-26-2018, 09:35 PM

You should consider any of the listed modules and buy them sold in sets. They approve hundreds of types and all should work.

Companies selling ram may be quite loose on their suggestions but look at the configurator web pages for what might fit and be usable too.

The only way a motherboard can be somewhat proven to work is to be tested at the factory.

I'd use their recommendations if you want a slightly greater chance of success. Faster is not better. Mixing is not better. Matched pairs or in this case 1 2 or 4 (or triples on some boards) tends to be best.

To be sure, server memory tends to be more reliable (when used in servers) but you pay for that.

keefaz · 01-26-2018, 09:49 PM

Maybe Corsair CMD16GX4M2B3200C16 (3200MHz) but yeah it's not cheap... I don't know your budget

(OC) means memory have OC capabilities I guess, I'd use a XMP profile in BIOS and let it at default, this should set memories to advertised speeds

haertig · 01-26-2018, 11:54 PM

Thanks for the replies and help everyone.

I found a blurb on an Intel page for the i5-8600K CPU that said this processor supports memory of type DDR4-2666.

Sooo... since the motherboard says it supports that, and the CPU says it supports that, and the 2666 stuff was only marginally more expensive then either the 2400 or 2133 stuff, and the specific memory I found on the sellers website was on the motherboards approved list (the exact part number) ... that's what I bought. I don't know if I would need to overclock anything to get the most from that memory, but it was only $10 more than the 2400/2133 stuff (those were both the same price). So for only $10, if the 2666 ends up being functionally the same as the 2400/2133 in my setup, no big financial loss.

Final purchase (from Newegg): ASUS Z370-A motherboard PLUS Intel i5-8600K processor PLUS Corsair Vengeance LPX 2x8GB DDR4 2666 (CMK16GX4M2A2666C16)

They had a $10 rebate on the motherboard, and also $15 off the processor with a promo code. Plus rebates on both the SeaSonic power supply and Corsair case I bought alone with the mobo/cpu/memory. I just stumbled into these rebates and promo codes - they were on stuff that I had already decided to buy (without prior knowledge of the discounts). They also threw in a free mouse pad and a 3 year Avast anti-virus subscription as "gifts" (although I rarely use Windows, Avast is my anti-virus of choice when I do). I kind of lucked out today it seems. Except I hate filling out rebate forms!