B-Die CL16 vs D-Die CL15 - Ryzen 3000

[Miller2000]

Hi all,

My first thread in the forum. I have searched some but not been able to find anything directly related to my question.

Just upgraded to a Ryzen 3800x on a Asrock Taichi x570 motherboard. A final thing to decide on is the memory.

I bought the following memory: D-Die G.skill 3600 Mhz CL15 (F4-3600C15D-16GTZ) running with XMP settings giving the following latency: 16-15-15-35. (CL is automatically being increased to 16 due to Ryzen not accepting uneven values for CL (according to G.skill support themselves).) I tried activating "gear down mode" but did not change the CL.

I have run a few tests and am getting bad latency results and generally mediocre to bad results for the memory tests. Now I am trying to figure out why.

Results from MaxxMem and PerformanceTest V9.0:



I have ordered a pair of B-Die G.skill 3600mhz CL16 (F4-3600C16D-16GTZR ) as well, which are supposed to be B-die. However I am thinking that the CL15 rated memory theoretically should perform better even if they are not "supposed" to be run with an AMD. I want to make sure I have given the CL15 D-dies the correct settings for making a proper comparison.

Is there any reason for the B-dies to be expected to perform better than the D-dies at the original rated speed and latency?

 

[maxfly]

You should be able to tighten the timings of the b die kit. B die generally oc very well but ymmv.
You may or may not be able to run 14 14 14 or 15 15 15 with either kit depending on the amount of voltage you apply.
The latency of your d die isnt bad at all for a ryzen rig. You may be able to drop it slightly with tighter timings.
Try aida64 when you bench for latency.
GL!

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WELCOME TO OCF!

 

[Woomack]

I'm sure that the 3600 CL15-15-15 is a B-die, highest bin IC which only G.Skill released. I have one of these kits and they're not manufactured anymore (for like ~2 years). D-die wouldn't run at 3600 15-15-15 1.35V. Both D and E die were like 15-18-18 at this frequency and were mostly in CL16/17 kits. Also D-die is in 2x4GB kits / single rank and 2x8GB kits dual rank. Dual rank kits OC worse.

My 3600 15-15-15 kit runs at 3600 14-15-15 ~1.40V on Ryzen 3k. My 3200 CL14 Royal kit (B-die) runs at 3600 14-15-15 1.45V. Most other B-die that I had couldn't run at 3600 CL14 below 1.5V but some were from a higher frequency, 2400 SPD IC.

To make memory run at odd CL values you have to disable Gear Down option in memory tab. Then memory will run at CL13, 15, 17, ... Works fine on ASUS, Gigabyte and ASRock motherboards. Tested on ASRock X570 Extreme4 which is really close to the Taichi.

Btw. both memory benchmarks are pretty bad for memory comparison. Check AIDA64 for synthetic bandwidth/latency tests. For more daily usage comparison look at memory copy result as this is close to the internal Windows benchmark ( winsat from command prompt) and affects most applications.
From other memory tests, in a multithreaded environment, you can check Geekbench which has many memory tests. In general, it's better to compare performance in software that you use daily or games. Performance comparison of new Ryzen is tricky and most people don't understand that posting totally wrong conclusions "because all are saying that Samsung B is the best". On Ryzen the tightest timings are not the most important but of course help. Also, you can see that the difference between average and the best memory settings at 3600+ is like a 0-1% performance difference.