Question How reliable or extensive are memory support lists

[nmb255]

I'm looking at a motherboard and ram kits. The motherboard is Gigabyte Z390 Aorus Ultra. There is a memory support list.

I'm looking at two ram kits
Manufacturer code: CMK32GX4M2B3200C16
32GB (2x16GB) Corsair DDR4 Vengeance LPX Black, PC4-25600 (3200), Non-ECC Unbuffered, CAS 16-18-18-36, XMP 2.0, 1.35V

Manufacturer code: CMK64GX4M4C3200C16
64GB (4x16GB) Corsair DDR4 Vengeance LPX Black, PC4-25600 (3200), Non-ECC Unbuffered, CAS 16-18-18-36, XMP 2.0, 1.35V

The first kit is listed on the motherboard memory support list. The second kit isn't. From the descriptions the two kits seem to consist of the same memory modules, just one kit is 2x16 [listed by the vendor as dual channel] and the other kit 4x16 [listed as quad channel].

Is there any risk in getting the quad kit, or is it safer to get two of the dual kit?

Even more confusing is that the Corsair Memory Finder offers other kits which also aren't on the motherboard memory support list.

 

[jay32267]

The support list lists modules that I would like to assume were tested with the MB by the manufacturer and passed all the tests.

That;'s basically how I look at it anyway.

I have found that many many times (90%+) I have been able to use memory not on the support list and have it work just fine as long as it meets the MB specs.

I would say it's probably "safer" to use a module on the list....but I've had so much success using modules off the list.....that I don't necessarily go by the list....especially if it's not a new build.

 

[geofelt]

Best to buy ram that is explicitly supported by the motherboard ram QVL list or by the ram vendor support app.

Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
The internal workings are designed for the capacity of the kit.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards, can be very sensitive to this.
This is more difficult when more sticks are involved.
The underlying circuitry may differ among kits of the same specs.
Always buy a single matched kit.

If you need 64gb, buy a single 4 x 16gb kit if it shows up on the corsair ram selection app. ryzen operates in dual channel mode, even with 4 sticks.
I think it will not handle a 2 x 32 gb kit.

 

[clarkjd]

Best to buy ram that is explicitly supported by the motherboard ram QVL list or by the ram vendor support app.

Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
The internal workings are designed for the capacity of the kit.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards, can be very sensitive to this.
This is more difficult when more sticks are involved.
The underlying circuitry may differ among kits of the same specs.
Always buy a single matched kit.

If you need 64gb, buy a single 4 x 16gb kit if it shows up on the corsair ram selection app. ryzen operates in dual channel mode, even with 4 sticks.
I think it will not handle a 2 x 32 gb kit.

I agree with what you said, Just want to add that a quad channel ram kit would be more likely to work than 2 dual channel kits.

 

[nmb255]

I agree with what you said, Just want to add that a quad channel ram kit would be more likely to work than 2 dual channel kits.

There in lays the problem. The dual kit is listed, the quad kit isn't. The speed, timings and voltages are the same in both kits. To all intents and purposes it would seem that they are identical modules.

The dilemma is: Take a gamble on a non-listed kit; or a gamble on two listed kits. Third option is to find an alternative kit that is listed.

What we need is an unsupported list

 

[USAFRet]

There in lays the problem. The dual kit is listed, the quad kit isn't. The speed, timings and voltages are the same in both kits. To all intents and purposes it would seem that they are identical modules.

Except that one set came from the factory in Malaysia, and the other came from the factory in Thailand.
Each with ever so slightly different tolerances, plus or minus.

 

[nmb255]

The crucial memory finder does offer several kits for the z390 Aorus Ultra. None of them are on the Gigabyte Memory Support List though.

To the question in the title then - How reliable and extensive are the support lists. Is it the case that exhaustive testing is being done over a large sample of production units from several production runs to conclude compatibility, or are they compiled from supplied parts lists and technical specifications? The amount of testing to include and exclude everything on the market would be frankly staggering. To much to be believed is actually happening in my opinion.

At the bottom of the list this disclaimer is stated "Memory modules listed as above is for reference only. Due to massive memory models in market, we can only verify some of them". Plus it states that at 3200Mhz or higher the stability depends on the CPU.

 

[nmb255]

The support list lists modules that I would like to assume were tested with the MB by the manufacturer and passed all the tests.

This Jay, is where I started too. Assuming things where actually and physically tested. Then I found [near] identical kits not on the list. Hmm... was it tested and failed I wondered? Then I find kits on memory suppliers lists which are not on motherboard suppliers list. Hmm... Who is testing what? Then I think about how many permutations of Ram X Kit X Motherboard there are to test, and I start to wonder how long it would take to test and if these tests actually physically happening.

I like to think that some testing is being done. Hopefully it is. I expect the vast majority of the list is from specifications and not physical testing. What would be nice to have is a list of "In-Spec, Tested and Failed", in addition to the QVL.

 

[clarkjd]

This Jay, is where I started too. Assuming things where actually and physically tested. Then I found [near] identical kits not on the list. Hmm... was it tested and failed I wondered? Then I find kits on memory suppliers lists which are not on motherboard suppliers list. Hmm... Who is testing what? Then I think about how many permutations of Ram X Kit X Motherboard there are to test, and I start to wonder how long it would take to test and if these tests actually physically happening.

I like to think that some testing is being done. Hopefully it is. I expect the vast majority of the list is from specifications and not physical testing. What would be nice to have is a list of "In-Spec, Tested and Failed", in addition to the QVL.

Just because a certain memory module is NOT on the QVL for the motherboard doesn't mean that it won't work, simply that it hasn't been tested by the motherboard manufacturer. The manufacturer can't possibly test ALL possible combinations, or they would never finish testing! You can go at it a different way by going to the ram manufacturer's website and use their memory finder app. The ram manufacturer is more likely to test all of their memory in specific motherboards.