[SOLVED] Supported CAS Latencies - Two RAM sticks with different CL will work?

ShangWang

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Mar 26, 2021
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If I have two ram sticks, would they work if they have different CAS latencies? I see that ram has supported CAS latencies, what does that mean?
If one RAM stick was CAS 17 and the other was CAS 19, would the CAS 17 which supports CAS 19 use the slowest latency? Is that what it means by "supported?"

Also what does module number mean? Is it just the number assigned to a RAM slot? How come one says 0 and the other is 2? I'm assuming the 0 would be 1 but they made the numbers weird.
View: https://imgur.com/a/dgwKheR
 
Solution
It may or may not. It really is just the luck of the draw, mixing ram types. CPU-Z will tell you what speed and CL your ram is actually running at. Different boards are going to have different latencies that they support, hence the wide range. Your CL 17 stick would run at CL 19, if it is in channel B, and the CL 19 is in A. Your CL 19 stick would attempt to run CL 17 if it was in channel B. Channel A typically dictates what speeds and timings the other ram stick runs at.

logainofhades

Titan
Moderator
It may or may not. It really is just the luck of the draw, mixing ram types. CPU-Z will tell you what speed and CL your ram is actually running at. Different boards are going to have different latencies that they support, hence the wide range. Your CL 17 stick would run at CL 19, if it is in channel B, and the CL 19 is in A. Your CL 19 stick would attempt to run CL 17 if it was in channel B. Channel A typically dictates what speeds and timings the other ram stick runs at.
 
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Solution

ShangWang

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Mar 26, 2021
616
2
1,885
It may or may not. It really is just the luck of the draw, mixing ram types. CPU-Z will tell you what speed and CL your ram is actually running at. Different boards are going to have different latencies that they support, hence the wide range. Your CL 17 stick would run at CL 19, if it is in channel B, and the CL 19 is in A. Your CL 19 stick would attempt to run CL 17 if it was in channel B. Channel A typically dictates what speeds and timings the other ram stick runs at.
Thanks, I'm assuming it'd be safer to run the higher latency in channel a then. Also do you know why the module numbers are 0 and 2? I only have two ram slots so I'm confused why it skipped a number.
 

logainofhades

Titan
Moderator
My guess would be that your board starts with a 0, instead of a 1, or it is how that utility names it. Kinda like how programs show the first core, on a CPU, as core 0. In a 4 ram slot, for dual channel, normally you use slots 1 and 3, or 2 and 4. So in your case it would be 0 and 2, or 1 and 4, depending on whether it is the mobo or that utility naming it, if your system had 4 ram slots. As it only has 2 slots, it goes 0 and 2. 0 being the primary module for Bank A, and 2 being the primary of Bank 2.
 
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ShangWang

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Mar 26, 2021
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My guess would be that your board starts with a 0, instead of a 1, or it is how that utility names it. Kinda like how programs show the first core, on a CPU, as core 0. In a 4 ram slot, for dual channel, normally you use slots 1 and 3, or 2 and 4. So in your case it would be 0 and 2, or 1 and 4, depending on whether it is the mobo or that utility naming it, if your system had 4 ram slots. As it only has 2 slots, it goes 0 and 2. 0 being the primary module for Bank A, and 2 being the primary of Bank 2.
Ty
 
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