Question Ram compatibility with CPU

[KnightsCross]

I am going to be getting a MSI B450 Tomahawk mobo, a Ryzen 7 2700x cpu, and have read and heard that there are some memory sticks that aren't "compatible" or "approved" for use with this cpu. I was looking at G. Skill with this model number. Is there going to be some sort of bizarre compatibility issue? Also, does timing have anything to do with what order you install memory sticks on a 4 slot mobo? or could I just stick the 2 16gb sticks in literally ANY of the slots? Thanks fellas/

 

[QwerkyPengwen]

You need DDR4 memory.
It would be best to have at least 3000mhz speed.
For two sticks you want dual channel.

Channels are labeled by letter with most boards these days having support for more than one set of ram in dual channel.

So for two sticks, put one of them in slot A1 and the other in slot B1.

Be sure to enable DOCP and XMP profile in BIOS.

G.Skill is a good brand for quality memory modules and has good compatibility.

 

[KnightsCross]

You need DDR4 memory.
It would be best to have at least 3000mhz speed.
For two sticks you want dual channel.

Channels are labeled by letter with most boards these days having support for more than one set of ram in dual channel.

So for two sticks, put one of them in slot A1 and the other in slot B1.

Be sure to enable DOCP and XMP profile in BIOS.

G.Skill is a good brand for quality memory modules and has good compatibility.

Sorry I meant to include a model number in my original post.
F4-3200C16D-32GTZR

thats the type. Do you see any sort of compatibility problems between that cpu, mobo, and ram?

 

[QwerkyPengwen]

You can literally use almost 99% of all RAM or there with your motherboard and CPU.

That's just how it all works.

As for whether or not said RAM you purchase will be guaranteed to run at its XMP on your system is another thing.

But I would say 95% of the time it will.

The RAM you've listed is the cheaper TridentZ with CAS 16 latency and therefore isn't on the QVL.
However, the CAS 14 latency variants are on the QVL, and from my experience, no matter what variant of TridentZ you go with, they work just fine.

 

[Karadjgne]

A2/B2 is recommended for Ryzen dual channel.

The Trident-Z series ending in GTZR is intended for Intel cpu compatability. The series ending in GTZRX is intended for AMD compatability. It's not that they aren't compatible, it's that the sticks labeled with an X have gone under serious amounts of testing on AMD motherboards and have the highest compatability ratings and least amount of possible issues requiring manual adjustment.
It's kinda like Levi's jeans, the difference between 501's and 505's, some ppl have a preference because they just fit better, even though they may be the exact same brand, size, cut etc.
Memory: G.Skill - Trident Z RGB 32 GB (2 x 16 GB) DDR4-3200 Memory ($170.99 @ Newegg)

 

[KnightsCross]

Thank you for all your help everyone. I need to ask, what is QVL? Also the CAS 16 latency, can you explain that and what it means? Is that part of the ram timing? I know almost nothing about timing.

 

[QwerkyPengwen]

yes. CAS latency is the timings.
QVL stands for "Quality Vendor List" also known as a compatibility list.

All this is, is a list of RAM that the motherboard manufacturer personally put through all the testing to ensure absolute perfect compatibility and performance.

It doesn't mean that something that is not on the QVL won't work or perform, it just means that it wasn't personally tested by the motherboard manufacturer on that board.

And typically, the board manufacturers don't bother to test the more budget friendly models of RAM, they always seem to only do testing on the more expensive modules with lower CAS timings and such.

 

[Karadjgne]

QVL is the Qualified Vendor List. It's a listing of ram that's been tried and found to function correctly on that mobo. It's listed by model number.

But here's the kicker. There's only a handful of actual ram OEM, they make ram for everyone. Gskill and Corsair are very popular brands, but they both use ram originally built by Samsung and SK Hynix. So when you see a 2133MHz gskill, it's probably got the exact same SK Hynix ram as 2133 Kingston, Corsair, Adata and many others. And most won't be on the QVL, only the few sticks actually tested. Furthermore, there's differences in model numbers, rgb, colors, kit sizes etc so a blue stick of gskill 2133 will have a different model number than a red stick from a 4pack of 2133, but be the exact same ram.

On top of that is changes due to price of the chips used. At the time of that test, gskill might have used 4 chips of SK Hynix ram to make an 8Gb stick. But a different contract with Samsung might be cheaper, so gskill ends up with 8 chips of Samsung ram to make the exact same 8Gb stick.

So all in all, at the end of the day, the QVL is useless as anything other than a list of ram that did work, so chances are good that similar ram will too. But no guarantee.

On the flip side, Kingston, G-skill, Crucial do extensive testing of their respective ram on every available motherboard, basically a QVL in reverse. If you talk to them, they can tell you exactly which of their ram will be best suited for your needs.
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There's 5 primary timings, like on my ram it's 10-11-10-30 2T. Cas is the first of those timings, so you'd see it referred to as Cas10 or CL10 or C10 ram, but it's all the same meaning. Generally the smaller the timings (compared to similar speed ram) the faster the ram operates and moves data to the cpu. So 9-10-9-27 1T would be slightly more efficient, therefore faster than 10-11-10-30 2T, at the same speed, but usually also costs more.
For 3200MHz, Cas16 is quite normal, Cas14 is a good bit faster, but the price goes from $80 for 16Gb of Cas16 to upwards of $130 for Cas14. You'll not really see much of any difference, they operate on a nanosecond timetable, but to a pc it's a world of difference.

 

[KnightsCross]

Ok I see. So could you technically install sticks of ram with different timings or is it important that all timings are the same?

 

[QwerkyPengwen]

Ok I see. So could you technically install sticks of ram with different timings or is it important that all timings are the same?

If you're talking about using ram that want purchased together as part of a kit then that's a whole different story and ball game.

Best not to mix ram. Simple as that.

 

[Karadjgne]

1 kit.
When the factory bundles ram into a kit/package, first it tests all the ram to see if it works. If it doesn't, they can immediately swap sticks around until it does. Final result being those 2/4/8 sticks are now factory guaranteed to work together.

2 kits.
Factory bundled 2 different packages. They only tested each kit individually, they don't test to see if each kit is compatible. Final result is you become the tester, if the kits aren't compatible you spend weeks on mailing and waiting for a new kit, and there's still no guarantee those 2 kits will play nice. Final result, you could spend 6 months in swapping kits and get no satisfaction.

Buy 1 kit of the size, speed, # of sticks you need. Do not mix-n-match.