2x8 single ranked diims or 4x8 single ranked? future proofing

[ProRules]

Hey guys.

I'd like to build a PC for the next 6-7 years +- 

I was thinking either waiting for Zen 3 or buying right now something like 3900X with a good high end X570 motherboard.

Other system parts i already have are:

Lian li PC-O10WX case.

SF750 Platinum PSU

G.Skill F4-3600C15D-GTZ

 

I've seen benchmarks that show a significant increase in performance using dual ranked memory dimms running in dual channel (10% gains sometimes)

And i was thinking about maybe ordering another set of Single ranked F4-3600C15D-GTZ kit.

Therefore 4 sticks of single ranked ram, will be equivalent to 2 sticks of dual ranked dimms. Also I will have 32 gigs of ram, which might be more beneficial in the near future as i already like to game and multitask on the second monitor.

 

Once thing i've read was that if i want to truly match dual ranked dimms perf, i should get a T-Topology motherboard when running 4 dimms. Any good T-Topology mobo? I know that Taichi is no longet T-Topology.

[Mathieu9836]

T topology will matter if you are an extreme overlocker, other then that i would just get 2x8GB, i will run faster then 4X4GB in almost any circumstances.

[ProRules]

1 minute ago, Mathieu9836 said:

T topology will matter if you are an extreme overlocker, other then that i would just get 2x8GB, i will run faster then 4X4GB in almost any circumstances.

How come?

32GB with 4 sticks of 8, single ranked dimms which can perform like two dual ranked dimms.

vs 16gb of 2 sticks of single ranked dimms.

 

What if i manage to run both at xmp speeds?

[Mathieu9836]

You will still be running in dual channel, not quad channel.

[porina]

18 minutes ago, Mathieu9836 said:

other then that i would just get 2x8GB, i will run faster then 4X4GB in almost any circumstances.

Please explain why, as that goes against my testing and experience. The 2 rank (or equivalently 2DPC) running doesn't really change synthetic benchmarks in ram bandwidth much, but in practice it seems to help with some kinds of mixed read/write intensive workloads. Given this choice, assuming the modules are otherwise the same rank, speed and timing, I'd go for 4x4 over 2x8 for performance. If the 8GB modules are dual rank (very rare now), then it would be equal.

 

Also OP's choice is not 2x8 vs 4x4, it is 2x8 vs 4x8, so quantity can also play a part.

[ProRules]

27 minutes ago, Mathieu9836 said:

You will still be running in dual channel, not quad channel.

Has nothing to do with channel but rather rank.

Dual ranked dimm is basically a dimm which has chips on both sides.

This results in usually a little loosened timings and clock speeds (IMC works harder too) but the CPU can access both sides simultaneously which can then actually increase the performance because you can run two tasks on the same ram module, each using one side if you will.

With single ranked ram, one task might have to wait for the other task that occupies the ram to complete.

 

Some applications can even prefer running 2 single ranked dimms per 1 channel, running single channel but dual rank. which means you give up dual channel, that's of course not recommended generally speaking.

 

In games, dual rank and dual channel are benefitial.

I might want to occupy 4 slots with 4 sticks of 8gb single channel dimms, those g.skill tridentz 3600 cl15.

Thing is, the motherboards..

Like 99% of them are daisy chain, 2 slots (1 per channel) are high spec, but the other two are usually low spec, that's my issue.

[ProRules]

26 minutes ago, porina said:

Please explain why, as that goes against my testing and experience. The 2 rank (or equivalently 2DPC) running doesn't really change synthetic benchmarks in ram bandwidth much, but in practice it seems to help with some kinds of mixed read/write intensive workloads. Given this choice, assuming the modules are otherwise the same rank, speed and timing, I'd go for 4x4 over 2x8 for performance. If the 8GB modules are dual rank (very rare now), then it would be equal.

 

Also OP's choice is not 2x8 vs 4x4, it is 2x8 vs 4x8, so quantity can also play a part.

Yes i was thinking about using 4 sticks of 8GB G.Skill 3600Mhz 15-15-15-35 2N 1.35V which are single ranked dimms.

Just don't know which motherboard can handle it well.

Are there any T topology ones? don't want 2 high spec slots + 2 low spec slots like with most daisy chain.

[Mathieu9836]

You said you want to futurproof your buy, how are you supposed to futurproof 4 sticks of RAM if you will have to remove 2 sticks to get more capacity. If you are not planning to do some extreme overclock i would not even worry about buying a T topology board and get the fastest RAM kit you can afford. IMO paying for a board just because it as T Topology and not overclocking the crap out of your sticks you are better off just buying 2 very fast sticks of 16GB each and have room for another 2 sticks in the futur.

Also when you overclock RAM sticks, having 4 sticks instead of 2 give you more chance to have a ''lower quality'' stick that will make all the other run at slower speed.

[porina]

7 minutes ago, ProRules said:

Yes i was thinking about using 4 sticks of 8GB G.Skill 3600Mhz 15-15-15-35 2N 1.35V which are single ranked dimms.

Just don't know which motherboard can handle it well.

Are there any T topology ones? don't want 2 high spec slots + 2 low spec slots like with most daisy chain.

I don't know about high performance mobos... I only have on kit rated above 3200, and with recent AMD bios it doesn't have any problems running at high speeds. I don't have enough of it to try 2DPC. BTW to my understanding, dual rank modules and running two dimms per channel aren't technically the same thing, although in practice, it is same assuming modules are single rank running 2DPC.

 

On the performance side, the only use I have where either 2R or 2DPC makes a noticeable difference is in Prime95-like workloads. I have 3200 dual rank modules and they perform way better than single rank 3600 or 4000, even with tinkering with IF clocks didn't make much difference otherwise. I was never able to personally prove this helps in games though. At least, whatever I tried to test didn't show a benefit from this. 

[ProRules]

5 minutes ago, Mathieu9836 said:

You said you want to futurproof your buy, how are you supposed to futurproof 4 sticks of RAM if you will have to remove 2 sticks to get more capacity. If you are not planning to do some extreme overclock i would not even worry about buying a T topology board and get the fastest RAM kit you can afford. IMO paying for a board just because it as T Topology and not overclocking the crap out of your sticks you are better off just buying 2 very fast sticks of 16GB each and have room for another 2 sticks in the futur.

Also when you overclock RAM sticks, having 4 sticks instead of 2 give you more chance to have a ''lower quality'' stick that will make all the other run at slower speed.

Well if i get 32GB total, I think it will be very futureproof for the next 6-7 years right :d

I am actually custom watercooling.

Prior i had 7700K binned and dellided running 5.2Ghz 24/7

With that 2x8GB 3600 CL15 oced ram.

[ProRules]

5 minutes ago, porina said:

I don't know about high performance mobos... I only have on kit rated above 3200, and with recent AMD bios it doesn't have any problems running at high speeds. I don't have enough of it to try 2DPC. BTW to my understanding, dual rank modules and running two dimms per channel aren't technically the same thing, although in practice, it is same assuming modules are single rank running 2DPC.

 

On the performance side, the only use I have where either 2R or 2DPC makes a noticeable difference is in Prime95-like workloads. I have 3200 dual rank modules and they perform way better than single rank 3600 or 4000, even with tinkering with IF clocks didn't make much difference otherwise. I was never able to personally prove this helps in games though. At least, whatever I tried to test didn't show a benefit from this. 

There is a russian benchmarking guy, he did many tests and dual ranked ram definitely gave more fps in games too.

Something like 10-15 fps even.(in the over 100 fps range, not 30 to 45 type of difference, but still)

[Mathieu9836]

32GB is not worth it at the moment for gaming, games barely need 8GB. Ram is getting faster and faster, next year or two 4000mhz might be usual thing, so your 3600mhz will be ''slow''

[porina]

8 minutes ago, ProRules said:

There is a russian benchmarking guy, he did many tests and dual ranked ram definitely gave more fps in games too.

Something like 10-15 fps even.(in the over 100 fps range, not 30 to 45 type of difference, but still)

If it is worth it is up to you. For my gaming, I stop noticing somewhere around 100+ fps. I even cap lower than that to reduce power load.

4 minutes ago, Mathieu9836 said:

32GB is not worth it at the moment for gaming, games barely need 8GB.

I kinda agree in that, 16GB is probably the sweet spot to generally not hit ram capacity limits, but it never hurts to have more. At worst, it provides a ram cache so reduces loading times on already accessed stuff, although how much over a good SSD, it probably wont be much in it.

[Mathieu9836]

49 minutes ago, porina said:

I kinda agree in that, 16GB is probably the sweet spot to generally not hit ram capacity limits, but it never hurts to have more. At worst, it provides a ram cache so reduces loading times on already accessed stuff, although how much over a good SSD, it probably wont be much in it.

It's kind of difficult to know how much time 16GB will be enough for gaming, and how much time 3600mhz will actually be considered fast since we already hit 4800mhz on DDR4 and last year 4000mhz was very very fast, and getting anything over 4000mhz is kinda stupid since most CPUs can't run that, you need to bin them for the best memory controller, Intel does achieve around 4200mhz, and some does more then that, but Ryzen not sure how it handle 4000MHZ+

[porina]

1 minute ago, Mathieu9836 said:

It's kind of difficult to know how much time 16GB will be enough for gaming, and how much time 3600mhz will actually be considered fast since we already hit 4800mhz on DDR4 and last year 4000mhz was very very fast, and getting anything over 4000mhz is kinda stupid since most CPUs can't run that, you need to bin them for the best memory controller, Intel does achieve around 4200mhz, and some does more then that, but Ryzen not sure how it handle 4000MHZ+

Outside of niche cases, like heavily modded games, I don't see ram capacity requirements going up much as they still have to cater somewhat for lower spec systems also.

 

As for speed, with the consideration that running speed isn't everything, I still see anything above 3200 as a luxury. This is the officially supported speed for Zen 2, and Intel has yet to officially reach it, even if we've been using it for like 5 years or more.

 

While it is not an area I focus on myself, I believe more of the faster ram kits being released are optimised for AMD more so than Intel. The newer bios and settings included to allow faster ram does seem to be helping. I've yet to see proof that running much above 3600 is worth it on AMD though.

 

The only reason I have >3600 speed kits is for competitive benchmarking, which is a niche in itself.

[Mathieu9836]

If you don't OC then what i say is worthless, but lets say you do, running 4 sticks put more stress on your memory controller and there is more chances you loose signal integrity, so if you are barely stable at 1T you can try 2T, but if you already run at 2T there is no higher command rate available, and going from 1T to 2T already increase latency. So general rule is that lower clockspeed with tighter timings is better then higher clockspeed with looser timings, but 1T is also faster then 2T and you mostly won't need to increase command rate at 3200mhz which is not alway the case for overclocked 3600mhz kits and higher.

 

I have no experience with 3600mhz+ rated kits, but i do have 2 kits of 3000 and 3200mhz that can't run at 1T higher then 3400mhz with common timings, but can run 3800mhz at CL18 2T. The same kit rated for 3200mhz CL16 is running at 3200mhz CL14 with timing around B-dies stuff with very good latency.

 

All this to say, T topology have little to no effect on what you plan to do with it, i would just get the best motherboard i can within my budget and get a 3200mhz CL14 2X8GB kit and try to OC the crap out of it, if one day you ''need'' more memory just buy the same kit they will probably be cheaper, or get the new stuff that will probably run same kind of timings but at a faster clockspeed.

[ProRules]

52 minutes ago, Mathieu9836 said:

If you don't OC then what i say is worthless, but lets say you do, running 4 sticks put more stress on your memory controller and there is more chances you loose signal integrity, so if you are barely stable at 1T you can try 2T, but if you already run at 2T there is no higher command rate available, and going from 1T to 2T already increase latency. So general rule is that lower clockspeed with tighter timings is better then higher clockspeed with looser timings, but 1T is also faster then 2T and you mostly won't need to increase command rate at 3200mhz which is not alway the case for overclocked 3600mhz kits and higher.

 

I have no experience with 3600mhz+ rated kits, but i do have 2 kits of 3000 and 3200mhz that can't run at 1T higher then 3400mhz with common timings, but can run 3800mhz at CL18 2T. The same kit rated for 3200mhz CL16 is running at 3200mhz CL14 with timing around B-dies stuff with very good latency.

 

All this to say, T topology have little to no effect on what you plan to do with it, i would just get the best motherboard i can within my budget and get a 3200mhz CL14 2X8GB kit and try to OC the crap out of it, if one day you ''need'' more memory just buy the same kit they will probably be cheaper, or get the new stuff that will probably run same kind of timings but at a faster clockspeed.

Hey thanks for the reply.

If i go for daisy chain motherboard, it makes the upgradability to 4 dimms not worth it to me.

That's because daisy chain usually doesn't like 4 dimms, unless i go for high end 500$ boards.

I already own 3600mhz kit, and it's rated at 2T stock.

[Mathieu9836]

38 minutes ago, ProRules said:

Hey thanks for the reply.

If i go for daisy chain motherboard, it makes the upgradability to 4 dimms not worth it to me.

That's because daisy chain usually doesn't like 4 dimms, unless i go for high end 500$ boards.

I already own 3600mhz kit, and it's rated at 2T stock.

Daisy chain is not worthless for 4 DIMM it just doesn't like overclock as T topology does, because T Topology split lanes right in the middle of the 2 DIMM on the same channel. Daisy chain does not split right in the middle so basically you will have one DIMM on each channel having a shorter lane then the other on the same channel that's why there is an increase in stability over one channel ( usually channel A) on a Daisy Chain board. So your 2 DIMM kit might run at 3400mhz CL14 on extreme OC and at 3333mhz CL14 with all 4 DIMM used, but on general use, both T Topology and Daisy Chain can run 2 or 4 DIMM at rated speeds.

 

It only really matter if you plan to overclock really really high near unstable your RAM sticks, other then that you won't really notice the difference. I might be wrong but for the little that i know about extreme memory overclocking is at it really only matter if you plan to break records, 99% of PC users don't even know how many channel there is on their board.

 

An other thing you can try is get your 3600mhz kit (which is an overclock) to run at 3000 or 3200mhz with a 1T command rate and run tighter timings, then compare latency on both speed (3600mhz CL15 and 3200mhz CL13 if you can run it)

[ProRules]

26 minutes ago, Mathieu9836 said:

Daisy chain is not worthless for 4 DIMM it just doesn't like overclock as T topology does, because T Topology split lanes right in the middle of the 2 DIMM on the same channel. Daisy chain does not split right in the middle so basically you will have one DIMM on each channel having a shorter lane then the other on the same channel that's why there is an increase in stability over one channel ( usually channel A) on a Daisy Chain board. So your 2 DIMM kit might run at 3400mhz CL14 on extreme OC and at 3333mhz CL14 with all 4 DIMM used, but on general use, both T Topology and Daisy Chain can run 2 or 4 DIMM at rated speeds.

 

It only really matter if you plan to overclock really really high near unstable your RAM sticks, other then that you won't really notice the difference. I might be wrong but for the little that i know about extreme memory overclocking is at it really only matter if you plan to break records, 99% of PC users don't even know how many channel there is on their board.

 

An other thing you can try is get your 3600mhz kit (which is an overclock) to run at 3000 or 3200mhz with a 1T command rate and run tighter timings, then compare latency on both speed (3600mhz CL15 and 3200mhz CL13 if you can run it)

I bet i could do 3600 CL14 or maybe CL16 1T with 1.4/1.45V instead of the base 1.35V 

Maybe some play with the timings in the bios (like the larger scale timings (there are dozens)).

The thing about daisy chain, is that i've seen some videos comparing 4x4gb single rank and 2x8gb single rank.

Both configs being on the same clock speeds and latencies. It does seem like the 4x4 performs 5-10% better in games in avg fps, yet in some instances the 1% lows are worse, and i think that's because of the daisy chain layout on the motherboard.

Think about it, if you use only the fastest slots, that's fine, but when running 4 dimms, two slots will be slower and so that might cause lower 1% or 0.1% than usual when tasks get completed on the slower slots.

That's why I wanted T topology.

[Mathieu9836]

If you really want to squeeze the last few ponies, i would look at the 9900K or the 9700K