Question Does RAM bottleneck exist?

bumblebee953

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For my new system I'm thinking of grabbing the Corsair Dominator Platinum 32 gb (either 2x16gb or 4x8gb kits). With my budget I'm most likely looking at 3200 with 16 latency.

I'm waiting on the 5800X for the cpu and have decided on ASUS Prime X570-Pro for the motherboard. And of course waiting on 3080.

With team red, I can't use Intel XMP but can at least use DOCP with the ASUS board. Is 3200 still kinda the official sweet spot speed with AMD? I wonder if 3200 is kinda bottlenecking the 5800X/3080 monster combo. Does that even happen?
 
I wouldn’t use the term bottleneck but RAM speed can affect performance. However until reviews are out we don’t know what the sweet spot will be for 5000 series. There was some unsubstantiated claim going around that 4000mhz would be the new sweet spot but there is no evidence yet.
 

2plash6

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Yes. It does exist, but it won't happen with your combination of components.

There are two factors that can cause ram bottlenecks.
The speed is one, and if you put 128gb of ram with an i7 6700 for example, then that will result in a bottleneck.
 

bumblebee953

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I wouldn’t use the term bottleneck but RAM speed can affect performance. However until reviews are out we don’t know what the sweet spot will be for 5000 series. There was some unsubstantiated claim going around that 4000mhz would be the new sweet spot but there is no evidence yet.
If not 4000mhz, would 3600mhz be at least a safer bet than 3200? There is a kit with 3600 @ 18 at a similar price. I wonder if it's worth it going with 3600 at a latency loss.
 

mamasan2000

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The current gen Ryzen, the 3000-series, RAM sweetspot is 3600-3733 Mhz. It's not going to be lower. It could be the same.
3000-3200 Mhz, CL 16 RAM is kinda bad, you never know what you get. Could be anything under the sun. Cheapest stuff that you can't overclock or tinker with one bit, if it even boots.
 
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hotaru.hino

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For my new system I'm thinking of grabbing the Corsair Dominator Platinum 32 gb (either 2x16gb or 4x8gb kits). With my budget I'm most likely looking at 3200 with 16 latency.

I'm waiting on the 5800X for the cpu and have decided on ASUS Prime X570-Pro for the motherboard. And of course waiting on 3080.

With team red, I can't use Intel XMP but can at least use DOCP with the ASUS board. Is 3200 still kinda the official sweet spot speed with AMD? I wonder if 3200 is kinda bottlenecking the 5800X/3080 monster combo. Does that even happen?
The rumor points that AMD says DDR4-4000 is going to be the performance sweet spot for Zen 3 processors. If true, then yes, DDR4-3200 won't be adequate. But we won't know for sure once people do testing on it.

As for RAM performance affecting the GPU, no, that doesn't happen. If the GPU is accessing RAM often, it probably ran out of VRAM which is an even worse issue.
 
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I haven't been keeping up on all the rumors and such for Ryzen 5000, so I don't know if there will be DDR 4000 support, but if it's anything like Ryzen 3000, you will still want to buy 2x16GB for the best chance at running your ram at the highest speed possible with dual rank ram module configurations.
 
Are 4-DIMM kits a problem with amd for some reason?
The memory controller on AMD CPUs are tied to the Infinity Fabric, so ram can't run as high as Intel CPUs. Infinity Fabric would need to run at half the desired ram frequency for higher frequencies, which is going to hurt performance or have diminishing. This is why 3600MT/s or 3733MT/s are the "sweet spot" for Ryzen 3000 ram frequencies.

The other issue is ram slot topology also affects the frequency the modules can run. Most motherboards use daisy chain circuit trace topology, which is easier to manufacture, but leaves you with the issue of one set of slots being capable of higher ram frequencies. Running four modules will force you to use lower frequencies. So for example, with Ryzen 2000, I have to run my 4x8GB modules at 3000 CL14, because 3066-3200 CL14 is unstable. I could probably run 3200 CL16, but it would be about the same performance as 3000 CL14.
 
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bumblebee953

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The memory controller on AMD CPUs are tied to the Infinity Fabric, so ram can't run as high as Intel CPUs. Infinity Fabric would need to run at half the desired ram frequency for higher frequencies, which is going to hurt performance or have diminishing. This is why 3600MT/s or 3733MT/s are the "sweet spot" for Ryzen 3000 ram frequencies.

The other issue is ram slot topology also affects the frequency the modules can run. Most motherboards use daisy chain circuit trace topology, which is easier to manufacture, but leaves you with the issue of one set of slots being capable of higher ram frequencies. Running four modules will force you to use lower frequencies. So for example, with Ryzen 2000, I have to run my 4x8GB modules at 3000 CL14, because 3066-3200 CL14 is unstable. I could probably run 3200 CL16, but it would be about the same performance as 3000 CL14.
Hmm this is a tough one... Looks like for the Corsair Dominator Platinum RGB White version 32gb, if I want to go with 2 sticks, there's only either the 3200/16 or 4000/19 choices. And I read that 4000/19 is worse than 3200/14. So there's kinda no choice at all there...
 
Hmm this is a tough one... Looks like for the Corsair Dominator Platinum RGB White version 32gb, if I want to go with 2 sticks, there's only either the 3200/16 or 4000/19 choices. And I read that 4000/19 is worse than 3200/14. So there's kinda no choice at all there...
You are getting ahead of yourself and over thinking ram speeds. We have no benchmark data or actual official information on what ram speeds Ryzen 5000 is capable of using and we don't know what future games will have higher fps with faster ram. Not many currently released games take advantage of ram faster than 3200 CL16.

The difference in game performance between 3200 CL14 and 4000 CL18-CL19 is not going to be enough to justify the cost of the either kits. Split the difference and get 3600 CL16. Most users wouldn't even notice a difference between 3200 CL14 and CL16 or 3600 CL16 and CL18. The only time you would likely notice a difference is in benchmarks if you put the effort into manually tightening memory timings.
 

bumblebee953

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Split the difference and get 3600 CL16.
That's the thing, the kit that I prefer does not come in those configurations. For 2-DIMM, there's only 4000/19 or 3200/16. I should probably mention that I really want the white version for my build. If I was to get the regular black version, at 3600 there's only CL18 available.
 
That's the thing, the kit that I prefer does not come in those configurations. For 2-DIMM, there's only 4000/19 or 3200/16. I should probably mention that I really want the white version for my build. If I was to get the regular black version, at 3600 there's only CL18 available.
Honestly 3600 CL16 vs CL18 or 3200 CL14 vs CL16 is only going to be maybe a 1-3% difference in games. You might see a 5-8fps difference at most with either speeds or timings. My advice when picking a kit is to get the lowest cas latency with the lowest even timings that fits your budget and has the aesthetics you want. CL16-18-18 would likely be a higher quality kit than CL16-19-19.

What are the kit models you are looking at; Post a link if you can? Maybe there is another store you can buy from that has a larger selection.
 
I'm looking directly on Corsair's site. The speed/latency configurations other than the two that I mentioned are simply not available.
Good god! $400-500 for the DDR4 4000 2x16GB kit. Do you actually need to have specifically the Corsair Dominator Platinum RGB. These kits don't even have good specs to be honest. $300 for 4x8GB 3600 CL18-19-19-39 is a terrible price and somewhat terrible timings. If you buy any of these kits, you would be paying a ridiculous premium for the heat spreader only when you could get a different brand/kit for a better quality ram kit with better ram chips for less than half the cost.
 

bumblebee953

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Good god! $400-500 for the DDR4 4000 2x16GB kit. Do you actually need to have specifically the Corsair Dominator Platinum RGB. These kits don't even have good specs to be honest. $300 for 4x8GB 3600 CL18-19-19-39 is a terrible price and somewhat terrible timings. If you buy any of these kits, you would be paying a ridiculous premium for the heat spreader only when you could get a different brand/kit for a better quality ram kit with better ram chips for less than half the cost.
I was hoping Black Friday would yield better prices. I know the Trident Z kits (especially the Neo for amd) are some of the most recommended but something about the offset rgb stripe just bothers me.
I was also looking at the Thermaltake Toughram series but they only seem to come in 2x8gb kits.
 

bumblebee953

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I know the Trident Z kits (especially the Neo for amd) are some of the most recommended
On that topic, the special Neo ones are optimized for Amd but these kits also come in 4x8gb configs which as you guys say is not desirable because of the lowered performance. Can these 4-DIMM kits still be said to be "optimized for Amd" then?
And if I were to get a Neo kit, these are only optimized for the current 3000 gen Zen 2 cpus right? When I get a 5800x, would these kits still be "optimized"? Or would G.Skill release new kits to work with the new gen CPUs?
 
On that topic, the special Neo ones are optimized for Amd but these kits also come in 4x8gb configs which as you guys say is not desirable because of the lowered performance. Can these 4-DIMM kits still be said to be "optimized for Amd" then?
And if I were to get a Neo kit, these are only optimized for the current 3000 gen Zen 2 cpus right? When I get a 5800x, would these kits still be "optimized"? Or would G.Skill release new kits to work with the new gen CPUs?
You should just wait and see how things pan out with Ryzen 5000 and its ram capabilities before buying anything. Ryzen 5000 releases in 2 weeks on Nov 5th.
 
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