DDR4-3600 for Ryzen 3700x: Dual Rank vs. Tighter Timings

[mikegray]

I'm building a Ryzen 3700x system from scratch. I plan to build on an ASUS Strix X570-E (which has particularly good RAM compatibility), and do some memory overclocking for best performance.

 

16gb is enough for my needs; HOWEVER: I've found that I can get either of two G.Skill RAM kits for almost the same price (about $5 more for the 32gb kit):

 

1) A 2 x 16gb DDR4-3600 kit with looser timings. F4-3600C17D-32GTZR (17,19,19,39)

 

2) A 2 x 8gb DDR4-3600 kit with tighter timings. F4-3600C16D-16GTZR (16,16,16,36)

 

While the 2 x 8gb sticks have tighter timings, the 2 x 8gb kit is single rank, whereas the 2 x 16gb kit is dual rank. From what I've read so far, dual rank actually trumps tighter timings - but which would you choose?

 

For example, see the following article (INCLUDING PAGE 2!) https://www.tomshardware.com/reviews/amd-ryzen-3000-best-memory-timings,6310.html

 

Note: Before you enlighten me about 32gb being pretty much useless outside of some specific use case scenarios: YEAH, I know! (That said: MAYBE I can get some better caching performance with 32gb - but I'm not getting hopeful.

 

[MartinKweh]

i was reading about this for a while and i think the dual rank is actually slower. id say go for the single rank with tighter timings. though ask for more inputs as im not that informed about the topic.

 

 

https://www.oempcworld.com/support/singlevsdualram.html

 

[DoctorNick]

It pretty much depends on price. It won't make alot of difference irl. But of course the kit with tighter timings is better. It's a Samsung B-die kit  and you will be able to get 4000mhz +- out of it.

[mikegray]

27 minutes ago, Martin2132 said:

i was reading about this for a while and i think the dual rank is actually slower.

That's what I would have thought - until I read the Tom's Hardware article!

 

Here's their conclusion: 

 

Going from two ranks to four ranks of memory is by far the best way to improve performance in memory-bottlenecked applications. At current memory density, that usually means having at least 32GB (even if you don’t think you’ll use that much capacity). 

[mikegray]

1 minute ago, DoctorNick said:

It pretty much depends on price. It won't make alot of difference irl. But of course the kit with tighter timings is better. It's a Samsung B-die kit  and you will be able to get 4000mhz +- out of it.

Yeah - that's EXACTLY what I assumed until I read the TH article - which really threw me for a loop.

 

BTW, yes: This thread makes the term "first world problems" look generous - but if you can have either item for the nearly exact same price, it's natural to get a little bit stuck on which to buy!

[mariushm]

Dual rank puts a bit more strain on the memory controller, therefore it reduces the potential for overclocking.

Single rank is easier, so it has higher overclocking potential but in the end it depends on the memory chips and how well the motherboard bios is optimized for those particular memory chips (ex a motherboard bios may be very tuned for samsung e die chips, but less for micron chips, so ram sticks with samsung e die chips may overclock better on this motherboard).

 

Some cheaper motherboards may have difficulties using 4 dual rank memory sticks at high frequencies - lowering the default frequency a notch will get them working.

For example, you may not be able to run 4 sticks at 3600 Mhz if they're Dual Rank, but they'll run fine at 3200 Mhz or 2933/3000 Mhz.

 

I would consider the benefits of having 32 GB vs gaining maybe less than 1% of performance by overclocking from 3600 Mhz to 4000 Mhz or whatever you plan. Latency matters very little, most applications don't care about it.

I doubt you'll notice the performance increase in most games, but the extra capacity would probably help you more often.

[mikegray]

15 minutes ago, mariushm said:

I would consider the benefits of having 32 GB vs gaining maybe less than 1% of performance by overclocking from 3600 Mhz to 4000 Mhz or whatever you plan. Latency matters very little, most applications don't care about it.

I doubt you'll notice the performance increase in most games, but the extra capacity would probably help you more often.

Helpful stuff!

 

- I actually checked the Strix-E for 3600 compatibility with the 32gb, dual ranked kit, and it looks like it should play nice. (Asus QVL + anecdotal in a reddit thread or two. OTOH, G.Skill QVL doesn't list any ryzen boards in their QVL for the 32gb kit.)

 

- Anyway, yeah: I think I'll take the 32gb set - it won't be useful very often, but all things being equal, I might as well have it ...

[mariushm]

Yeah, pretty much ALL x570 boards should be fine. They're much better built than B450 and x470 boards, better attention to signal quality and all that.

 

Majority of motherboards have no problems with TWO dual rank memory sticks, as I said the cheaper boards may have issues with four sticks. With just two, even the cheapest boards will probably work just fine.