Question 2x16 vs 4x8 on a dual channel board

[Trancestor]

Is there any definitive answer for what of the two is better in gaming? I see so many different answers and i am not a smart enough man to think by myself, i just want to know which of the two should i buy for my next rig, i dont really care if the 4x8 would cost a bit more.

There's this video where the difference is quite huge in favor of 4 slots:

View: https://www.youtube.com/watch?v=IDKzCsC9Svs


Something memory interleaving something daisy chain something idfk...are those tests actually legit or is he missing something there?

 

[william p]

I think that's legit. But some older CPUs and chipsets backed down the timing s when all slots are filled. The 45nm original i7 did that.
I would look for tests on your specific CPU and motherboard if possible. Many of the benchmarks let you see detailed reports with RAM latency charts. It may be that not all motherboards and chipsets are equal in their abilty to do that.

 

[sizzling]

I asked similar a while back and didn’t get far https://forums.tomshardware.com/threads/2x8gb-vs-4x4gb-gaming-comparison-intel.3479216/

 

[Karadjgne]

There is no definitive answer because there's too many variables. Yes, 4x gets slightly better fps as it's running 2 sets of dual channel, so data has the second channels to swamp the cpu with. However, if the cpu is reaching data input saturation, that becomes moot, it can only use so much at any given time so fps becomes equitable.

There's also the additional strain on the memory controller, which doesn't affect Intel nearly as much as Ryzen, Ryzens don't like 4x sticks and have a hard time with ram speeds in excess of 2933MHz when all 4 are populated, or 2400/2666MHz if using 1-2Gen cpus.

So while there maybe a bonus with that 1 game, for that 1 pc, that's not to say it'll be the same with other games, or to any viable extent, and can depend on the pc itself too.

So rule of thumb says 2 sticks is the most compatible, fastest, often cheaper, while being more well rounded option.

 

[Trancestor]

There is no definitive answer because there's too many variables. Yes, 4x gets slightly better fps as it's running 2 sets of dual channel, so data has the second channels to swamp the cpu with. However, if the cpu is reaching data input saturation, that becomes moot, it can only use so much at any given time so fps becomes equitable.

There's also the additional strain on the memory controller, which doesn't affect Intel nearly as much as Ryzen, Ryzens don't like 4x sticks and have a hard time with ram speeds in excess of 2933MHz when all 4 are populated, or 2400/2666MHz if using 1-2Gen cpus.

So while there maybe a bonus with that 1 game, for that 1 pc, that's not to say it'll be the same with other games, or to any viable extent, and can depend on the pc itself too.

So rule of thumb says 2 sticks is the most compatible, fastest, often cheaper, while being more well rounded option.

9900k 2080 ti Gigabyte Z390 Auros Pro, i'm guessing that's a good comparability?
I just have such a great opportunity of a deal right now to get these beauties: https://www.gskill.com/product/165/...lDDR4-3600MHz-CL16-16-16-36-1.35V32GB-(4x8GB)
I'm 99% about to get these and switch my "crappy" corsair vengeance 3000mhz 2x16 kit

 

[Third-Eye]

On my Ryzen 5 2600, I got about 5-7fps increase with 4x8GB at 3000Mhz compared to 2x8GB at 3200Mhz with almost the same CL14 timings in the games I benchmarked months ago. The main difference between 2x8 and 4x8, other than speed, is I went through the effort of using Dram Calculator to dial in tighter timings for 3000Mhz. If you need 32GB of ram or can find a 3200+Mhz 4x4 kit for a reasonable price, it's worth using 4x modules if playing Battlefield 5 and other games that get a 10+fps boost. Otherwise, for most people, it makes more sense to save the money for a better GPU or CPU. Most games either don't get a boost or only up to about 10fps average boost.

 

[60frames]

Is there any definitive answer for what of the two is better in gaming? I see so many different answers and i am not a smart enough man to think by myself, i just want to know which of the two should i buy for my next rig, i dont really care if the 4x8 would cost a bit more.

There's this video where the difference is quite huge in favor of 4 slots:

View: https://www.youtube.com/watch?v=IDKzCsC9Svs


Something memory interleaving something daisy chain something idfk...are those tests actually legit or is he missing something there?

If you want a proper explanation see this-https://www.youtube.com/watch?v=D_Nb9CohSBM

 

[Trancestor]

My IQ is really low, i need very simple answers lol. From what i coud find my mobo Gigabyte Auros Pro is T-Topology so 4x8 3600mhz ram should give me more fps than 2x16 (same exact specs) yes? Even if its not every game out there i'd still be happy.

 

[L-Bombo]

My IQ is really low, i need very simple answers lol. From what i coud find my mobo Gigabyte Auros Pro is T-Topology so 4x8 3600mhz ram should give me more fps than 2x16 (same exact specs) yes? Even if its not every game out there i'd still be happy.

I'm learning too (first ever PC build was a week ago) but I just read a Buildzoid thread commenting that T-Topology is best suited by all four DIMMS being full. Sorry I can't find the reference. It was 20 browser tabs or so ago!

Buildzoid also said identifying T-Topology versus the Daisy Chain one can be tricky - has Gigabyte said it's T-Topology?

 

[Trancestor]

I'm learning too (first ever PC build was a week ago) but I just read a Buildzoid thread commenting that T-Topology is best suited by all four DIMMS being full. Sorry I can't find the reference. It was 20 browser tabs or so ago!

Buildzoid also said identifying T-Topology versus the Daisy Chain one can be tricky - has Gigabyte said it's T-Topology?

Googling shows various forum members say that the master and pro wifi are t-topology but no specific one on the pro, someone said all gigabyte z390's are t-top. I wish there was an actual way to check so i could be sure...

 

[60frames]

Googling shows various forum members say that the master and pro wifi are t-topology but no specific one on the pro, someone said all gigabyte z390's are t-top. I wish there was an actual way to check so i could be sure...

Have you tried Ryzen DRAM calculator? If you download and go in the help section there is a link which provides all the information about how to identify T-Topology or daisy chain.

 

[alceryes]

You also need to factor in dual rank vs. single rank DIMMs.
Contrary to many reports out there, dual rank does give an advantage over single rank. Compatibility can be an issue though, which is usually why single rank is the knee-jerk recommendation.

 

[Karadjgne]

Especially with Ryzens, single rank is a preference, dual rank gets limited by the Infinity Fabric associated with ram speeds. Usually doesn't bother Intel as Intel doesn't use that association, so ram speeds have very little to no cpu performance gains, only software performance gains. Some software can show marked gains with faster, higher bandwidth, lower timing ram, some software doesn't show any gains, depending on what the software needs and how the ram is used.

Don't confuse single/dual rank with single/dual channel, they are entirely different things.

 

[60frames]

Especially with Ryzens, single rank is a preference, dual rank gets limited by the Infinity Fabric associated with ram speeds. Usually doesn't bother Intel as Intel doesn't use that association, so ram speeds have very little to no cpu performance gains, only software performance gains. Some software can show marked gains with faster, higher bandwidth, lower timing ram, some software doesn't show any gains, depending on what the software needs and how the ram is used.

Don't confuse single/dual rank with single/dual channel, they are entirely different things.

I don't understand why RAM changes make so much difference with Ryzen. Is it it's hardware needs or a BIOS bug??

 

[Karadjgne]

Amd uses a thing called Infinity fabric. It's basically the communications between the cores. It's based on ram speeds in a 1:1 multiplier upto 3733MHz, after which it switches to a 2:1 multiplier, so uses ram at half the speeds.

The premise is that the faster the ram, the faster the cores communicate with each other, the faster the cpu, so higher fps. The difference between 2133 and 3200MHz is about 20% increased performance.

Considering that the price of 2133/2400MHz ram is often equal to or more than 3000/3200MHz, at the same Cas16, it's a no brainer to go for the faster ram in many cases.

 

[60frames]

Amd uses a thing called Infinity fabric. It's basically the communications between the cores. It's based on ram speeds in a 1:1 multiplier upto 3733MHz, after which it switches to a 2:1 multiplier, so uses ram at half the speeds.

The premise is that the faster the ram, the faster the cores communicate with each other, the faster the cpu, so higher fps. The difference between 2133 and 3200MHz is about 20% increased performance.

Considering that the price of 2133/2400MHz ram is often equal to or more than 3000/3200MHz, at the same Cas16, it's a no brainer to go for the faster ram in many cases.

Considering the complications involved in the Ryzen processors I think that Intel is still a lot better option. Not everyone is an electronics engineer to predict accurate results about performance. Now after purchasing Ryzen I am thinking that I should have gone for Intel for gaming. And AMD does not even have a proper guide for consumers about which RAM configuration will be best for their processors.