Question DDR5 bottom line - speed or timings?

[evident]

I'm building a 13th gen Alder lake system for a somewhat overkill home server - proxmox for VM's that will be hosting a blue iris DVR, an unraid NAS, and other typical home server stuff. I'm upgrading from a 15 year old haswell system and would like to get 2x32GB modules. being out of the loop, what should i be looking for? is PC6400 a decent speed nowadays? I'm looking at the following modules:

• DDR5 6400 (PC5 51200)
• Timing 32-39-39-102
• CAS Latency 32
• Voltage 1.40V

https://www.newegg.com/g-skill-64gb/p/N82E16820374432

 

[igor_kavinski]

The voltage seems a bit too high on that kit. There are CL28 DDR5-5600 1.1V kits available. I prefer those.

 

[igor_kavinski]

1.35V but still not bad: https://www.memoryc.com/42570-64gb-...l28-dual-channel-kit-2x-32gb-black.html?fc=US

 

[igor_kavinski]

• DDR5 6400 (PC5 51200)
• Timing 32-39-39-102
• CAS Latency 32
• Voltage 1.40V

Usually +/- 2ns in CAS latency is the same general performance as +/- 400 MHz in RAM speed. So a comparable kit would be DDR5-6000 CL30. The latter would only be slow in very bandwidth sensitive applications. Otherwise, both kits should perform roughly the same. That's why I really like CL28 DDR5-5600. If you go with a decent DDR5-7200 kit, it might be possible to run that at CL28 DDR5-6000 for pretty sweet performance.