[SOLVED] Ram for rendering mostly : cas 12 + 2400mhz or cas 13 +2666mhz?

[stacielovesmalphite]

The title says it.
Both sets are 2x8gb ddr4, hyperx Predator.
I'm open to other brands, just didn't find any, with such low cas.
I'll be using it 80% for rendering and 20% for 1080p gaming. My monitor is 75hz freesync.

 

[vapour]

can you list the whole rig specs?
real latency = CAS/speed, so they are on par. However, 2666 is easier to overclock than 2400. If same price, I will get 2666 13. If you can overclock, I will get 3200 C16 etc.

 

[stacielovesmalphite]

No, cas 16 is huge for rendering, and 3200 won't make much of a difference to 2666,if at all.
Higher frequency mostly means more FPS in games, which isn't my primary target.
I'll be mostly working on Unity, 3ds max and blender.
I will not be overclocking.

Will be paired with Ryzen 1700 and rx 570 8gb.

The Ram models are:

https://www.amazon.com/HyperX-Predator-2400MHz-HX424C12PB3K2-16/dp/B072JTNJD4


https://www.amazon.com/HyperX-Predator-2666MHz-HX426C13PB3-16/dp/B072MFHQ3K/ref=mp_s_a_1_1?ie=UTF8&qid=1548693157&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=Hx426c13pb3%2F16&dpPl=1&dpID=41SeLb3SNzL&ref=plSrch

 

[vapour]

since you are using Ryzen. ram scaling requires faster ram and you only care about true latency = CAS/speed. 3200 16 CAS is your friend. In other words, 2133 Latency 15 is slower than 3200 latency 16.

https://www.crucial.com/usa/en/memory-performance-speed-latency

ram scaling on Ryzen: https://www.legitreviews.com/ddr4-memory-scaling-performance-with-ryzen-7-2700x-on-the-amd-x470-platform_205154

 

[geofelt]

Ryzen is picky about ram.
Not all DDR4 ram will be supported.

Your first concern should be compatibility with your motherboard.
The ram should be explicitly supported by your motherboard's ram QVL list or by the ram vendor explicitly supporting it on it's ram selection app for your motherboard.

As to the cas/speed question, I can't answer but I suspect the difference to not be major.

 

[stacielovesmalphite]

I know all this. It mostly refers to gaming.

Can someone, with rendering programs knowledge, answer to my actual question, plz? The options are only those two in the title , only the brand (hyperx) is negotiable.

 

[vapour]

Those ram scaling benchmark is not just for games, one more source showing faster ram is good to have for rendering: https://www.techpowerup.com/reviews/AMD/Ryzen_Memory_Analysis/7.html

 

[stacielovesmalphite]

Vapour, this very link that you sent, shows that 3200 mhz ram is just 1,3% faster than 2133mhz, in blender.

 

[vapour]

Yes, however it depends on application as well. What software are you using? In general, faster and lower latency is faster, just how much.

 

[stacielovesmalphite]

Already said that I'm using blender...

Like I've said, I've done tons of research, only need someone to tell me if there is a noticeable difference between cas 12 and 13.

 

[vapour]

If that is the case, pick the cheaper one. roughly the same performance.

 

[nuttynut]

I'm surprised that latency has such an effect on rendering. I would expect that lower latency would be better for realtime graphics like gaming.

 

[stacielovesmalphite]

I'm guessing they are quite similar.... Well, I will either use the 2666 choice (cheaper) or wait a bit and get sth else that I have found ;
A series of ram that combines 3200mhz with just 14 cas and I think it's worth having such higher frequency with sacrificing just 1/13 cas so I'll go with it.
It's a g. Skill trident z and the only one that has 14 cas on 3k + frequency.
Thank you all!

 

[stacielovesmalphite]

I found a tool to tell if your ram's frequency is worth its cas.
The lowest the
Cas/freq is, the better.

Also, checked the rams I posted, and their manufacturer's site says that the the 2666mhz /c13 can be downgraded to 2400 /c12 on the right xmp profile.
https://www.kingston.com › dataSheetsPDF
HX426C13PB3/8 HX426C13PB3/8 Memory Module Specifications - Kingston
In both cases, the winner is the c13/2666mhz one