How big a difference is MIXED RAM compared to dual and quad channel?

[DragonPlus7]

i mixed my RAM to 64GB from my previous build , one pair ddr4 3000 and another ddr4 3200. I put them in my four slot like this where A is 3000 and B is 3200:

A-B- A-B

or should it be placed like

A-A-B-B

Does dual channel or quad channel make a big difference coz id rather have more ram then less

or

should i put back my quad channel at the cost of less ram???

[Phénomènes Mystiques]

It will only run at 3000Mhz but you do need all their CAS the exact same or you will run into issues - I would rather on dual/quad channels but at a very low CAS.

[DragonPlus7]

引用自 WinterSolstice：

It will only run at 3000Mhz but you do need all their CAS the exact same or you will run into issues - I would rather on dual/quad channels but at a very low CAS. :csd2smile:

i was able to to set XMP in bios to 3200mhz !!! i dont know how LOL. Maybe those 3000mhz can go 3200 but differences in CAS is one 18 and 16.

[Phénomènes Mystiques]

引用自 DragonPlus7：

引用自 WinterSolstice：

It will only run at 3000Mhz but you do need all their CAS the exact same or you will run into issues - I would rather on dual/quad channels but at a very low CAS.

i was able to to set XMP in bios to 3200mhz !!! i dont know how LOL. Maybe those 3000mhz can go 3200 but differences in CAS is one 18 and 16.

I have seen Samsung B-Die that can go above rated specs, most RAM can be OC easily but most times only one step or two, I guess this qualifies, as for CAS, this might get a bit sticky.

[DragonPlus7]

引用自 WinterSolstice：

引用自 DragonPlus7：

i was able to to set XMP in bios to 3200mhz !!! i dont know how LOL. Maybe those 3000mhz can go 3200 but differences in CAS is one 18 and 16.

I have seen Samsung B-Die that can go above rated specs, most RAM can be OC easily but most times only one step or two, I guess this qualifies, as for CAS, this might get a bit sticky. :csd2smile:

When i put the RAMS in the setup below Where B is th the 3200Mhz and A is the 3000Mhz:

B-A-B-A

my pc would not boot.

i put one pair of RAM in and went to BIOS and set to AUTO 2400, and setup Where B is the 3200Mhz and A is the 3000Mhz:

A-B-A-B

then it worked and i was able to set XMP to 3200. I dont know how tho.

I checked CPUZ app and the ram is NOT in Dual channel but it still works in single channel.

maybe different motherboards has differences where the primary slot is located ( in my case B ). The fastest RAM should be placed in the primary slot first. Just a thought with the RAM placement.

[Phénomènes Mystiques]

Yes, dual and quad channels will not work with mixed RAM as far as I know but I do not usually mix RAM like this but it is interesting to read tho - perhaps you are right about different MB's, I know there are some people that work with all types of boards that frequent this forum so they would be more incline to answer that question - but as always, if it works, it works as long as you see performance increases not decreases, I say, it is a victory.

[_I_]

mixed will run at the speeds of the slowest dimm
if all dimms installed are the same speed with similar timings, there will be almost no difference

4 dimms is often capped by the cpus memory controller before anything else

4 dimms is not quad channel on consumer boards, the cpu only has 2 channels, talking to one pair or the other pair at one time

[Illusion of Progress]

As long as a given mis-matched pairing works, then the only thing you "lose" is the higher speed (or lower timings) of the better kit.

So you're missing out on 200 MHz worth. I wouldn't say that's a major deal, but whether it's worth doing depends on if you even need 64 GB to begin with.

When comparing faster 32 GB to slower 64 GB, it works as follows.

Faster 32 GB is marginally better as long as you're using less than 32 GB.

Slower 64 GB is substantially better once you're using over 32 GB.

Four DIMMs doesn't make it quad channel, by the way. The fact that you're referencing A1/A2 and B1/B2 signifies it is a dual channel platform. What adding more DIMMs does is populate each channel with more DIMMs. But it will still be dual channel.

I would put the matching DIMMs in every other slot, but as long as they work together, it's unlikely to matter since they will all be running "like one another" anyway (and if they aren't, you'll have issues regardless).

[A&A]

Depends on the ram dies, some RAM kits will just work perfectly fine.
If the first one is 3200MHz CL18 and the second one is 3000MHz CL16, you shouldn't have a problem.

[Viking2121]

Should be like the first one (A-B- A-B) for a better chance to work, It snot quad channel, but still dual channel.

I've mixed ram in the past with good results, but I've also mixed ram before and didn't have good luck with it at all so its a hit or miss, can't say you'll be fine, sometimes it wont show its ugly face until a certain load on the machine.

But yeah as other have mentioned, it will down clock to 3000mhz, the bios may even set it lower to like 2133 or 2400mhz, I'd try 3000mhz first and see how it does, stress test it, Then bump it up to 3200mhz see if it boots and is stable, never know, 3200mhz should be achievable on the 3000mhz kit to be honest, but sometimes it might not, be it from crappy binned ram chips, to mixing the ram, or even the CPU memory controller.

[PopinFRESH]

I'd suggest using the CPUz validator and then post the link here so people can actually see what hardware you are talking about in order to be able to actually help you; rather than providing guesswork and rule-of-thumb which may be generally true.

AFAIK both AMD and Intel similar memory technologies to improve mixed memory; Intel calls it FlexMode. None of those configurations are ideal but depending on what you are doing with your PC may still be beneficial if the additional memory capacity is actually needed. If you are primarily using it for gaming then you'd be better off just using the 64GB 2x32GB kit on its own (which ever kit was the faster one). Very little in regards to gaming is going to need/use 64GB let alone 128GB (assuming you mean you have two 64GB kits for a total of 4x 32GB DIMMs).

[r.linder]

Channels are almost always staggered;

1) A2, B2, A1, B2

or

2) B2, A2, B1, A1

with the first being the slot closest to the CPU socket, and the last being the furthest from the CPU socket


Mixing RAM is usually fine at least as long as they have the same IC manufacturer and type, sometimes there are issues when mixing ICs, and as always, running more 4 DIMMs puts more stress on the CPU's IMC so timings often need to be tweaked to keep things stable

[GOD RAYS ON ULTRA™]

引用自 DragonPlus7：

i mixed my RAM to 64GB from my previous build , one pair ddr4 3000 and another ddr4 3200. I put them in my four slot like this where A is 3000 and B is 3200:

A-B- A-B

or should it be placed like

A-A-B-B

Does dual channel or quad channel make a big difference coz id rather have more ram then less

or

should i put back my quad channel at the cost of less ram???

The problem with doing what you're doing is the outcome is never favorable. It's really that simple.

I'll bet almost no one mixes dimms on here. They might do it on a secondary pc, or maybe their wife's pc or another loved one.

I'm always against doing it. I won't even do it on an office pc. Ive had too many gremlins show up and it turned out to be mixed dimms.

People that have PCed long enough know exactly what I'm talking about. It gets to a point where you just know to avoid setups like that.

[DragonPlus7]

引用自 GOD RAYS ON ULTRA™：

引用自 DragonPlus7：

i mixed my RAM to 64GB from my previous build , one pair ddr4 3000 and another ddr4 3200. I put them in my four slot like this where A is 3000 and B is 3200:

A-B- A-B

or should it be placed like

A-A-B-B

Does dual channel or quad channel make a big difference coz id rather have more ram then less

or

should i put back my quad channel at the cost of less ram???

The problem with doing what you're doing is the outcome is never favorable. It's really that simple.

I'll bet almost no one mixes dimms on here. They might do it on a secondary pc, or maybe their wife's pc or another loved one.

I'm always against doing it. I won't even do it on an office pc. Ive had too many gremlins show up and it turned out to be mixed dimms.

People that have PCed long enough know exactly what I'm talking about. It gets to a point where you just know to avoid setups like that.

ive replaced them 4x8gbs.