That 4.2GHz all core result is just about as identical to my 3.98GHz core average PBO result as it can be. I wonder if it's purely down to my memory speed advantage making up the 200MHz per core disadvantage or if it's something else (Infinity Fabric, motherboard differences, BIOS settings, etc.)? I'm going to run a 4.2 all core run and maybe a run with my memory brought down to 3600MHz and see what happens.
In the cinebench thread and working with
@Det0x he pointed out something to me about 1:1 infinity fabric and RAM. I actually bought two sets of RAM for my 3950x rig. The first set was a 2dimm 32GB 3600MHz C16 set and the other, which I bought maybe a couple or three days later because I thought it'd perform better (and before the rig was pieced together) was a 2dimm 16GB 4266MHz C19 set.
I started with the 16GB 4266MHz set and only just Sunday night swapped to the 32GB 3600MHz set as a result of the Cinebench thread. On a source I was encoding in vidcoder, I was getting ~15fps encode speed on the 4266MHz RAM. After I swapped to the 3600MHz RAM I was getting ~23fps. Cinebench numbers only went up like 100 points by comparison.
I'm confused by the numbers I saw, not sure if it even makes sense to me, and I'm pretty tempted to swap RAM back around for further testing, as it's not like I documented everything in a spreadsheet. It's all in my head and the only real programs I used were Cinebench, Vidcoder, PassMark Performance Test, and Ryzen Master. The memory scores were a good bit higher in PassMark. I don't remember the scores, but I remember the 4266MHz test said I was like 93 percentile and the 3600MHz RAM said 99 percentile.
I would say Ryzen folks should look at their Ryzen Master at the RAM area and see if it's coupled or decoupled.
The infinity fabric basically maxes out at 1833/1866 as near as I can tell, for most people. So RAM at 3600 to 3733 with low timings, I'm thinking is a sweet spot.
Here's a couple things I was reading yesterday:
Going above 3,733MHz can tank your raw memory latency, and that's down to the ol' Infinity Fabric
www.pcgamesn.com
stub Memory speed on Ryzen has always been a hot subject, with AMD’s 1000 and 2000 series CPUs responding favorably to fast memory while at the same time having difficulty getting past 3200MHz in Gen1. The new Ryzen 3000 chips officially support memory speeds up to 3200MHz and can reliably run...
www.gamersnexus.net