For 100% stable system, should I get RAM w/ highest SPD frequency and ignore XMP?

[ss88]

Looking to build an Alder Lake system running DDR4 RAM. I care more about maximizing stability than maximizing performance. When deciding on which RAM to get, should I ignore XMP frequency and just focus on SPD frequency, and plan on running in SPD mode?

Does anyone even make DDR4 RAM that runs at 3200MHz in SPD mode?

Or can XMP be 100% stable if you pick RAM that is in your motherboard's QVL list?

 

[JSHamlet234]

3200 XMP should be extremely easy to run, there's really no reason overthink it.

 

[pitingres]

I'm seriously tempted to suggest building a Ryzen system instead, using ECC memory, and choosing one of the motherboards that actually implements the error correction.

 

[Snowknight26]

Or can XMP be 100% stable if you pick RAM that is in your motherboard's QVL list?

Going by the QVL is your best bet, but just because a stick isn't listed on there doesn't mean it won't work or that it's not stable. Look at it more from a business perspective that ensures compatibility.

There's no reason not to use XMP, but to answer your other question..

Does anyone even make DDR4 RAM that runs at 3200MHz in SPD mode?

Yes, there are plenty of sticks that run at 3200MHz without XMP. A lot of UDIMMs that support 3200MHz don't use JEDEC extensions.

For example:

Micron's 18ASF4G72AZ-3G2 line is 3200MHz CL22-22-22-52 by default (and ECC).

 

[kirbyrj]

To what end are you seeking a 100% stable system? For example, I have an Alder Lake setup running regular unbuffered non-ECC memory, I did many memory stability tests and it will run for days/weeks on end without issues usually only requiring a reboot for Windows updates. I consider this "100% stable" for my requirements. Is there a possibility that software or a one-off hardware memory error could occur? Absolutely.

QVL is a joke. At best it shows you what they tested with at the time the motherboard was released. Test your memory using something like TestMem5 with a custom config and just see if it works after enabling XMP. If it doesn't, send the memory back and get a different set.

 

[dasa]

I'm seriously tempted to suggest building a Ryzen system instead, using ECC memory, and choosing one of the motherboards that actually implements the error correction.

That or if it must be Alder Lake go with DDR5 since it has ECC.

Trouble with the SPD 3200 RAM is the high latency making it not much better than 2133c15.
SPD RAM is not really more stable it just follows the base spec like 1.2v vs 1.35v which doesn't really make a difference to power use or reliability.