2 vs 4 64gb RAM for 3900x

[Lalisa]

I am upgrading from 16gb RAM (3200 CL16) to 64gb but I'm not sure which would perform well between these two:

G.Skill 64gb (4 x 16gb) 3600 CL16 vs G.Skill 64gb (2 x 32gb) 3600 CL18

 

I've read some saying that using 4 ram would stress the memory controller and/or you wouldn't get the exact speed.

I want to hear your thoughts on this to help me which one I should get 

Btw, I'm using Asus Crosshair 8 Wifi Mobo.

[BlazerBuddy]

Just now, Lalisa said:

I am upgrading from 16gb RAM (3200 CL16) to 64gb but I'm not sure which would perform well between these two:

G.Skill 64gb (4 x 16gb) 3600 CL16 vs G.Skill 64gb (2 x 32gb) 3600 CL18

 

I've read some saying that using 4 ram would stress the memory controller and/or you wouldn't get the exact speed.

I want to hear your thoughts on this to help me which one I should get 

Btw, I'm using Asus Crosshair 8 Wifi Mobo.

I would say, just get the 2 32gb as yes, it is true. Having 4 sticks will stress the memory controller more. With 2 sticks, you can overclock more and better stability.

[svmlegacy]

R9 3900X?

[Lalisa]

Just now, svmlegacy said:

R9 3900X?

Yes

[svmlegacy]

Just now, Lalisa said:

Yes

Unless it's a bottom 0.1% real potato, you should have no issues running 3600 MT/s.
The lower latency is preferable, but it isn't a huge deal, if it's a fair bit more expensive.

[Jurrunio]

If you will tune memory manually, 2 sticks is better than 4

 

If you'll just enable XMP and never touch memory settings again, 4 will be faster.

[svmlegacy]

17 minutes ago, CircleTech said:

For bandwidth reasons, 4 memory sticks is better than 2 (for something like threadipper). This is why most people reccomend for example running a threadripper CPU in Quad-channel as opposed to single channel. 4x the memory means almost 4x the speed.

 

Of course in this situtaion for Ryzen it's a wash because the most you can get out of a 3900X is dual-channel anyway. 4 memory sticks running in a dual channel configuration will not improve speed beyond running 2 sticks in dual channel.

 

But I'm going to reccomend also using 2x32GB sticks here but for a different reason, and I would even reccomend 2x32 if this was threadripper: Higher memory capacity always has significantly higher resale value later. Just look at the prices for DDR3. A 4GB stick of DDR3 is worth about $10, but the same memory in an 8GB form factor is worth $25. That's not a linear price scale, so Why does the 8GB stick have a 5 dollar premium over the 4GB stick? Because people need to upgrade their older machines with more memory later and may only have 2-4 slots to do it with. Thus they will pay more for a higher capacity stick.

Forgoeing years of performance for $5-20 is hardly a smart decision. Technology drops in value worse than cars, so this is kind of a moot point. Always aim for 1 DIMM per channel, leaving the additional slots for future expansion.

[Jurrunio]

48 minutes ago, CircleTech said:

4 memory sticks running in a dual channel configuration will not improve speed beyond running 2 sticks in dual channel.

It will. Not only are the timings tighter, but it should benefit from being quad rank while 2x32gb is only dual rank (unless it's the stacked kit which is super tall, but those barely appear in the market)

 

48 minutes ago, CircleTech said:

 so Why does the 8GB stick have a 5 dollar premium over the 4GB stick? Because people need to upgrade their older machines with more memory later and may only have 2-4 slots to do it with. Thus they will pay more for a higher capacity stick.

It's also because people want to pair those older CPUs with 16gb memory (so 2x8gb). I doubt anyone still on AM4 will need more than 32GB when DDR5 becomes popular.