Question Can i mix different latency ram of the same manufacturer? or with different memory module? Hyper X Fury Ram

[Vlp3r]

I already have an HyperX Fury Black 8GB 2133MHz CL14 with the model number HX421C14FB2/8



"HX" being HyperX , "4" is DDR4 , 21 is 2133 mhz , C14 is 14 latency , FB2 being Single Rank configuration module.



Now i don't seem to find this item anywhere. Either i have to go for the same ram with dual rank configuration which is HX421C14FB/8, everything matches except for the memory module.



There's an other option with the same manufacturer which seems to be a higher frequency 2400 , single rank (FB2) but the latency is 15 where as my existing one is 14.



Which one to pick? either the 2400 mhz with the same memory module configuration with different latency or 2133 mhz which has the same frequency , same latency but different memory module?



P.S : All of them have the same voltage and all of them are from the same family of Hyper X fury.

 

[cherry blossoms]

For best compatability, you should get memory in matched sets. In theory, mismatched sticks should work at the slowest setting / timing for each, and the computer should handle this. In practice, this might cause stability issues.

 

[Vlp3r]

For best compatibility, you should get memory in matched sets. In theory, mismatched sticks should work at the slowest setting/timing for each, and the computer should handle this. In practice, this might cause stability issues.

So I'm planning to get this "HX424C15FB2/8" with my existing "HX421C14FB2/8 " The only thing different is the latency which is 14 for my existing one and 15 for the new one which I'm opting to buy. No issues right?

 

[cherry blossoms]

Again, no guarantees Vlp3r. This depends on how well your motherboard and CPU handle it. Some computers do and are able to run the memory at the slowest values of the pair. Some will give you instability. If unstable, depending on how much control your motherboard gives you, you may be able to get it stable by specifying the memory settings manually. Please note that compatibility not just a matter of PRIMARY settings such as:

Voltage

CAS Latency (tCL)
RAS to CAS delay (tRCD)
Row Precharge Time (tRP)
RAS Active Time (tRAS)
Command Rate (CR)

that people normally think of, but also:

Write Recovery Time (tWR)
Refresh Cycle Time (tRFC)
RAS to RAS Delay Long (tRDD_L)
RAS to RAS Delay Short (tRDD_S)
Write to Read Delay Long (tWTR_L)
Write to Read Delay Short (tWTR_S)
Read to Precharge (tRTP)
Four Active Window (tFAW)
CAS Write Latency (tCWL)

and

tREFI
tCKE
tRDRD (_SG, _DG, _DD, _DR)
tRDWR (_SG, _DG, _DD, _DR)
tWRRD (_SG, _DG, _DD, _DR)
tWRWR (_SG, _DG, _DD, _DR)


Which the system may or not be able to handle differences.

This doesn't even get into XMP stability issues.

It sucks to have to replace a working DIMM. Popping in a similar one MAY work, may give subtle errors or instability issues, or may not work period.

I would still recommend getting a MATCHED pair for that reason.