Benefits of RAM latency with Ryzen 5000 series

[KLN3830]

I’m in the process of putting together a 3090/5950x build, and have everything but the CPU (which should arrive in a week or two), and the RAM, which I’m still deciding on. I’m mainly looking at 3 64GB G.Skill B-Die kits at the moment:

 

4x16GBs G.Skill CL16 3600 (16-16-16-36) 1.35V

4x16GBs G.Skill CL14 3600 (14-15-15-35) 1.45V

4x16GBs G.Skill CL14 3600 (14-14-14-34) 1.45V

 

The CL14 kits are $90 and $170 more expensive than the CL16 kit, respectively. I plan to manually adjust the settings once I have everything up and running, but this is my first Ryzen build, and I have no first-hand experience with how well Ryzen in general, and the 5000-series in particular, scales with RAM speed and latency. I’m leaning toward the second kit, since it lists my motherboard (Dark Hero) in the QVL, whereas the third kit is apparently too new to even have one. It's also slightly less obnoxiously priced.

 

What I’m wondering is what what the actual, real world benefit would be of CL14 RAM with tighter timings, vs CL16, at the same speed (at XMP/DOCP timings). Most of what I've read on the subject either covers Zen 2, or is comparing something like CL14 3200 vs CL16 3600, etc., which makes the benefit of latency specifically more opaque. I'm also not clear if there is much, if any, performance hit in running 4 16GB sticks on a daisy chain board compared to 2x32GBs.

[SorryBella]

3 minutes ago, KLN3830 said:

4x16GBs G.Skill CL16 3600 (16-16-16-36) 1.35V

4x16GBs G.Skill CL14 3600 (14-15-15-35) 1.45V

4x16GBs G.Skill CL14 3600 (14-14-14-34) 1.45V

 

The CL14 kits are $90 and $170 more expensive than the CL16 kit, respectively. I plan to manually adjust the settings once I have everything up and running, but this is my first Ryzen build, and I have no first-hand experience with how well Ryzen in general, and the 5000-series in particular, scales with RAM speed and latency. I’m leaning toward the second kit, since it lists my motherboard (Dark Hero) in the QVL, whereas the third kit is apparently too new to even have one. It's also slightly less obnoxiously priced.

3rd kit has been problematic to some 5000 series system in this forum, and imo 3600CL16 is pretty much the limit of the diminishing return in performance with Zen 3 CPU.

[TrigrH]

40 minutes ago, KLN3830 said:

I’m leaning toward the second kit, since it lists my motherboard (Dark Hero) in the QVL

There is no 3600 gskill 4x16 kit on the QVL

 

The only two kits are these:

 

CORSAIR CMT64GX4M4Z3600C16(Ver4.31)

Hyper X HX436C18FB4K4/64

[KLN3830]

1 hour ago, SorryClaire said:

3rd kit has been problematic to some 5000 series system in this forum, and imo 3600CL16 is pretty much the limit of the diminishing return in performance with Zen 3 CPU.

This was my main concern with going for the faster kit, the potential trade-off between performance and stability at 64GB. I may be better off just going with the CL16 kit, since it's less likely to cause problems. It's just hard to resist the temptation to try and squeeze a bit more performance out of the build.

1 hour ago, TrigrH said:

There is no 3600 gskill 4x16 kit on the QVL

 

The only two kits are these:

 

CORSAIR CMT64GX4M4Z3600C16(Ver4.31)

Hyper X HX436C18FB4K4/64

I should have clarified in my earlier post, but I was referring to G.Skill's QVL rather than Asus

[TrigrH]

Just now, KLN3830 said:

This was my main concern with going for the faster kit, the potential trade-off between performance and stability at 64GB. I may be better off just going with the CL16 kit, since it's less likely to cause problems. It's just hard to resist the temptation to try and squeeze a bit more performance out of the build.

I should have clarified in my earlier post, but I was referring to G.Skill's QVL rather than Asus

I strongly recommend that you stick with this list:

https://dlcdnets.asus.com/pub/ASUS/mb/SocketAM4/ROG_CROSSHAIR-VIII-HERO_WI-FI/Memory_QVL_for_AMD_Ryzen_5000_X570-4DIMM.pdf

 

Please note the testing dots at the end of each line, for 4 dimm kits you need the last dot.

 

Normally QVL isnt a big deal but when we are trying to clock 64gb of ram at 3600mhz the rules change.