[SOLVED] Mhz and cas

[MdizzleD]

I'm trying to decide between two sets of ram right now: one is 3600mhz cas 14 and the other is 4000mhz cas 18. Both same brand, but the 4000mhz ram is much cheaper. What is your input when directly comparing these two sets? (Both are Teamgroup t-force xtreem argb).

 

[bfollett]

Officially support for your CPU by AMD is 3200. The manual you referenced says "AMD non-XMP Memory Frequency Support" at 3200. XMP is overclocking but has tested by the manufacturer to work at that speed. Your Motherboard with your CPU can overclock up to 5000+ The 3600 is the safe bet, you should just have to enable XMP and be done with it. If you go for the 4000 you might have to adjust/lower some of the timings to work with your CPU they're all different, there's no way to know without trying it. FYI that 3600 C14 is just as likely to be able to be run at a higher frequency to, so it's just a matter of how much work you want to put into it.

 

[Endre]

So what you're saying is that the 3600 is better because of the lower latency and that the slower DRAM speed is more stable while the 4000(is opposite) but COULD be a better performer when ran at the lower voltage?

Not quite.
Both 3600 and 4000 memory kits will run at those speeds with XMP enabled and voltage set @1.35V.
Both need overclocking the IMC.

So, the best things you can do is:

1. Make sure that the kit you’re buying is on the qualified vendor list of your motherboard.
2. Make sure you have decent cooling. Heat is the biggest enemy of PC components.

PS:
In my opinion a slower kit that runs at JEDEC specs will be more stable on the long run. For example:
DDR4-2666 CL16 @1.2V
DDR4-3200 CL18 @1.2V.
DDR4-3466 CL19 @1.2V.

 

[SamirD]

4000 cas 18 is $160 USD and the 3600 cas 14 is $210 USD

I'd go with the 4000 because if you get it running at 4000, that's faster than 3600, even with a small cas penalty.

And after reading the rest of the posts, while the 3600 is better ram, it's not the best value for the money, aka 'bang for buck', so I still say the 4000.

 

[mamasan2000]

OK. I understand the DIIMM placement, but it only shows up to 3200Mhz even thought the specs on Newegg say well over that. Is that because it is only verified up to 3200Mhz but not the overclocking speeds mentioned on Newegg? Also, SR & DR?

3200 Mhz is the Officially supported speed. Doesn't mean much in real life. My old Ryzen 1700 only supported 2666 Mhz but I had it at 3000. 3200 Mhz also worked.
SR & DR, Single Rank and Dual Rank. Dual Rank is 5-10% faster at 1440p. At 1080p the difference should be bigger.

View: https://www.youtube.com/watch?v=K0YWu4sHe7A


If you want Dual Rank with 2 RAM sticks...it's tricky. I have no idea how to find that out before purchase, if they are SR or DR. Not really listed usually. And they keep changing the chips on RAM constantly so what someone got when they bought the sticks doesn't mean you will also get the same. BUT...that is with 2 sticks. If you get 4 sticks that are single rank, those will operate in dual rank configuration.

 

[Endre]

3200 Mhz is the Officially supported speed. Doesn't mean much in real life. My old Ryzen 1700 only supported 2666 Mhz but I had it at 3000. 3200 Mhz also worked.
SR & DR, Single Rank and Dual Rank. Dual Rank is 5-10% faster at 1440p. At 1080p the difference should be bigger.

View: https://www.youtube.com/watch?v=K0YWu4sHe7A


If you want Dual Rank with 2 RAM sticks...it's tricky. I have no idea how to find that out before purchase, if they are SR or DR. Not really listed usually. And they keep changing the chips on RAM constantly so what someone got when they bought the sticks doesn't mean you will also get the same. BUT...that is with 2 sticks. If you get 4 sticks that are single rank, those will operate in dual rank configuration.

Kingston (HyperX) is one of those vendors that do mention the ranking of their DIMMs on the product web page.

Usually 16GB & 32GB DIMMs are dual-rank, while 4GB & 8GB DIMMs are single-rank modules.

 

[JWNoctis]

Kingston (HyperX) is one of those vendors that do mention the ranking of their DIMMs on the product web page.

Usually 16GB & 32GB DIMMs are dual-rank, while 4GB & 8GB DIMMs are single-rank modules.

Note that 16Gb DRAM chips are common on newer modules, which meant 1R for anything below 32GB.

Populating all four slots should get you the same performance bonus, though.

 

[mamasan2000]

Note that 16Gb DRAM chips are common on newer modules, which meant 1R for anything below 32GB.

Populating all four slots should get you the same performance bonus, though.

Mm, single rank, like this kit I just got: https://www.kingston.com/dataSheets/HX436C18FB4K2_32.pdf
HyperX Fury 3600 Mhz CL18 32 gigs.

 

[MdizzleD]

One more question. I understand that the 3600 c14 is better marginally, but does that still hold true in contrast to AMD stating that the 5000 series cpu's are made for 4000mhz ddims?

 

[Endre]

One more question. I understand that the 3600 c14 is better marginally, but does that still hold true in contrast to AMD stating that the 5000 series cpu's are made for 4000mhz ddims?

I believe that this claim is more of a marketing gimmick for AMD (pointing out that not every CPU can run at those speeds, but theirs does).
By their statement AMD means: “it can handle” those high frequencies.

So, no performance loss, in my opinion, by going with the 3600MT/s kit.