Threadripper 3960X Memory Question - 8x8 vs 4x16

I’m watching Wendell’s Threadripper mem vids, but I don’t understand if it’s better to go with an 8x8 or 4x16 configuration for the best RAM performance with 64GB.

I see you can get better clock speeds populating 4 dimms, but won’t 8 dimms give you better throughput? This will be a daily driver machine (gaming) + OLAP SQL Server dev box. I want the best infinity fabric speed possible.

My thought is to find kits with good timings at 1.35v, so I can bump the voltage if needed. This is the 4x16GB kit I’m looking at:

It’s really hard to find 8x8 kits rn, so it’s either two decent 4x8 kits or four superb 2x8 kits:

The board is the Gigabyte Designare. Full parts list here:

Use the 4x16 as that will give you the “best” of both worlds, high speed and “only” dual rank for more throughput.
While the Zen 2 memory controller is way stronger than the ones before it it may still not be possible to get 3600 with dual rank.
I don’t recommend to go with two of the same kits that have smaller amount of DIMMs in the kit, due to warranty and it may also be that you get different ICs with each kit, which then makes it hard to get them to work right together.

If you want the best IF speed possible then if you buy “only” a 3600 kit then you will get 1800 while most CPUs do 1866 so you need to either OC the kit to 3733 or buy a kit of 3733 right of the bat.
Some CPUs also do 1900, though I wouldn’t buy for one as the OC from 3733 to 3800 is rather easy to do in case your CPU actually does 1900.

I hear what you’re saying about kitted memory, but 3600MHz 14-15-15-35 @ 1.35V is going to be really good b-die. Plus Adata doesn’t offer 4x and 8x kits - just 1x and 2x, so it’s not like it was binned 2x for a reason.

Isn’t the worst case scenario that I have to loosen the timings to 16-16-16-36 or up the voltage to 1.45?

With Samsung B-die it toally depends on the temps of the chips, as I recently got to know firsthand.
If you can keep them under 50°C they are fine. Though that is almost impossible when air cooling a TR 3 CPU.
I would go, for safety, with Micron Rev. E, while just a tad bit slightly slower on XMP they are more heat resistant and a good binned Micron Rev. E can get very high speeds. You can get them from Crucial at 3600.

I say this after having some real problems with my Samsung B-die chips getting hot too long, you can read about it kinda here.

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