How Does RAM Affect FPS?

[Denganim20]

So I plan to get DDR4 2x8 RAM, so 16GB in total, but I'm wondering, does getting RAM with higher speeds increase FPS? Say if I had 3200MHz RAM paired with a Ryzen 5 1600 how much more FPS would be gained than having 2666MHz of RAM?

I assume the difference in FPS wouldn't be significant but I'm just curious. I have heard that higher clocked RAM helps Ryzen CPUs run better. Also if someone could suggest the sweet spot or sufficient amount of RAM needed, I'm all ears. All in all, I would appreciate it if someone could clear this up for me.

 

[Supahos]

16 GB is kind of the sweet spot and 3000/3200 MHz works well too. A lot of chips won't run above 2933 so going above 3200 is kind of pointless most of the time. Tom's has an article linked from AMD themselves comparing ramspeeds and latency effects with their processors, both seem to matter...

 

[eWOOD29]

The sweet spot is around 16gb of 2400. It's still pretty cheap and runs very well. I've heard that going from 2133 to 2666 gives about a 2-6fps increase in games but the fps increases get lower the higher you go. I fully recommend just sticking with DDR4 2400. Make sure to find DDR4 2400 ram with the lowest CAS latency as well.

 

[Supahos]

The above doesn't apply to gaming with ryzen.

 

[Denganim20]

The sweet spot is around 16gb of 2400. It's still pretty cheap and runs very well. I've heard that going from 2133 to 2666 gives about a 2-6fps increase in games but the fps increases get lower the higher you go. I fully recommend just sticking with DDR4 2400. Make sure to find DDR4 2400 ram with the lowest CAS latency as well.

The above doesn't apply to gaming with ryzen.

Could you elaborate on what CAS Latency is? I've heard of it but I've never fully known what it was.


And Supahos what do you mean "The above doesn't apply to gaming with Ryzen"?

 

[Supahos]

I mean ewoods post applies to Intel setups but not ryzen.


Cl means cas latency. It's how long a command for the memory takes to actually take place. The lower the cl the quicker it can react.

 

[eWOOD29]

The sweet spot is around 16gb of 2400. It's still pretty cheap and runs very well. I've heard that going from 2133 to 2666 gives about a 2-6fps increase in games but the fps increases get lower the higher you go. I fully recommend just sticking with DDR4 2400. Make sure to find DDR4 2400 ram with the lowest CAS latency as well.

The above doesn't apply to gaming with ryzen.

Could you elaborate on what CAS Latency is? I've heard of it but I've never fully known what it was.


And Supahos what do you mean "The above doesn't apply to gaming with Ryzen"?

I think he means that my comment only applies to Intel and not AMD, and he could be right. I'm much more of an expert with Intel than with AMD so if he knows what he's talking about with Ryzen, by all means give him a shot. As for CAS Latency; think of it as ping. The higher the the ping, the longer it takes for your computer to send information to the server and back again, just like the higher the CAS Latency, the longer it will take to transfer the info which slows down the connection no matter how fast the RAM itself is. Typically, when choosing Ram, you want the lowest CAS Latency you can get along with the highest speed. For DDR4 2400, CAS Latency 15 is about the sweet spot.

 

[InvalidError]

And Supahos what do you mean "The above doesn't apply to gaming with Ryzen"?

The "infinity fabric" which connects the cores to the memory and PCIe controller is tied to the memory clock, so Ryzen shows far steeper performance scaling with increased memory clock than Intel's chips.

 

[eWOOD29]

And Supahos what do you mean "The above doesn't apply to gaming with Ryzen"?

The "infinity fabric" which connects the cores to the memory and PCIe controller is tied to the memory clock, so Ryzen shows far steeper performance scaling with increased memory clock than Intel's chips.

Hm.. I wasn't aware of this. Sorry, OP, I'm very used to Intel chips and I tend to stay away from AMD so these other guys are your best bet.

 

[exroofer]

CAS latency is the timing the ram runs at.
So CAS 14, for example, is faster than CAS 18, if the frequency is identical. (3000 mhz or w/e)
Higher quality ram will usually run at tighter timings than cheaper ram at the same frequency.

I think perhaps the comment about not applying to gaming with Ryzen is in reference to the "sticking with 2400 ram"
Ryzen runs faster with higher frequency ram because the speed of the Infinity Fabric ( which ties the ccx modules together, and determines northbridge speed, which determines how fast the cpu communicates with the ram), is directly and linearly tied together.
Intel cpu's do not use this system, so 2400 ram vs 3200 ram shows only marginal increases in performance.
Ryzen, because of ram speed being tied directly to the above mention speeds, has MUCH more effect.

So if it is possible, running 3000-3200 ram that has decent CAS latency, is good for business with a Ryzen build.

 

[ledhead11]

CAS and Frequency

An analogy I came up with awhile back that's helped some people:

Think of it like answering a door or a phone call. Latency is how quickly you can pick up the phone or open the door. Frequency is like how fast you can speak once you do.

 

[Denganim20]

16 GB is kind of the sweet spot and 3000/3200 MHz works well too. A lot of chips won't run above 2933 so going above 3200 is kind of pointless most of the time. Tom's has an article linked from AMD themselves comparing ramspeeds and latency effects with their processors, both seem to matter...

So how good is this RAM for Ryzen, Corsair Vengeance LPX 16GB (2x8GB) DDR4 DRAM 3000MHz C15 Desktop Memory Kit? That's only $132 which is a good price but I found this as well, Corsair Vengeance LPX 16GB (2x8GB) DDR4 DRAM 3200MHz C16 Desktop Memory Kit, which is only $1 more. I think the 3000MHz RAM has faster latency than the 3200MHz RAM, and also my motherboard claims that it supports 3200MHz. Which is the better choice then?

 

[InvalidError]

16/3200*2 = 10ns latency
15/3000*2 = 10ns latency

Same latency but the 3200 RAM has 6.6% more bandwidth assuming your Ryzen chip and motherboard manage to clock it that high.

 

[Denganim20]

16/3200*2 = 10ns latency
15/3000*2 = 10ns latency

Same latency but the 3200 RAM has 6.6% more bandwidth assuming your Ryzen chip and motherboard manage to clock it that high.

Oh I see I guess they are the same latency then. In that case should I just get the Corsair Vengeance LPX 16GB (2x8GB) DDR4 DRAM 3200MHz C16 Desktop Memory Kit RAM, because it's only $1 more as opposed to the 3000MHz version? I'm almost positive I can run 3200MHz on my build.

 

[exroofer]

yes
I found, setting the frequency first in bios. then saving and letting the system boot, check freq with cpu-z.
Then reboot back in to bios, manually set ram timings, save, and let it boot.
Sometimes you need to increase ram boot voltage to maintain tighter timings.
Which is NOT the same as ram voltage....
Do this before you do the cpu OC.

Seems to work best.
And of course, make sure you are on the latest bios from the mobo manufacturer.

 

[Denganim20]

yes
I found, setting the frequency first in bios. then saving and letting the system boot, check freq with cpu-z.
Then reboot back in to bios, manually set ram timings, save, and let it boot.
Sometimes you need to increase ram boot voltage to maintain tighter timings.
Which is NOT the same as ram voltage....
Do this before you do the cpu OC.

Seems to work best.
And of course, make sure you are on the latest bios from the mobo manufacturer.

Thank you so much for the definitive answer! Now to clarify, to set ram timings manually you just turn off auto mode? And is there a setting called ram boot voltage in bios?

 

[exroofer]

Depends on mobo and bios.
My Crosshair 6 has literally well over 100 things I can tweak.
Some of which make me scared lol. Never change bios settings unless you are pretty darn sure what they do, at least the more arcane ones.........
The latest update that I installed added several settings that were not there previously.
Not all boards will support this kind of fine tuning.
However......

Step one, get the system running, at w/e it defaults to. Get Windows updated, drivers in, blah blah.
Step two, use it some, run a few basic benchmarks, check temps to make sure everything is all happy in there.
Step three, come back here, or hit Google with your exact mobo as a search, chances are there is a Youtube video that will point you in the right direction.
Step four, now that you have a few notes written down, and your system is all happy at w/e it defaulted to,
Go to the bios, set ram speed to the rated speed of the ram you bought.
Save, reset, and let it boot.
It can sometimes take a minute, going in and out of bios once or twice before booting is not uncommon on Ryzen, when dialing in an OC. They call it "ram training"
Once in Windows, launch CPU-Z, see what you wound up with.
Chances are you will hit your frequency target, with slightly relaxed timings.
"IF" you have ram timings and subtimings available to be manually set, you can then dial those in.
This becomes technical rather quickly.
*note. Before you mess with the timings, run the same benchmarks you did at all stock.
Like Cinebench R15 multithread etc. Don't really need hours of Prime95 for this.

Once you get that far, come back and let us know how ya made out.

Oh just as an aside. once I got my ram running at 3200, I tinkered a little with the cpu OC.
The easiest and most effective, for me, was to click "Load 4Ghz OC profile" in the bios.
And reboot.

Thanks Asus!