2x8GB here but think 4x16 would not change ram reliability
(1). I have no evidence that there was anything wrong with the two sets of Corsair RAM that had to be returned other than the fact they would not work with the Asus ROG Crosshair VII (Wifi) Motherboard and the Ryzen 2700x processor that I have.
(2). The two sets of Corsair RAM kit that had to be returned may actually be o.k. and work fine on an Intel motherboard.
(3). I have been told that having to order multiple kits before I get one where each stick in the kit work with Ryzen 2700X and AMD X470 Chipset is not that unusual.
(4). Driving 4x16GB is much more load to drive than 2x8GB, Reliability in terms of passing Memtest86 will depend on how much current is drawn which results in electrical noise which results in increased likelihood of memory test failure.
AMD, RAM suppliers and Motherboard suppliers need to work together to make it easier for consumer to get these Ryzen based systems working.
RE: "what a wrestle"
That is an understatement.
I have built many Intel systems, and I have only once had RAM issues, on my first Haswell based build.1 4x8GB kit had to be replaced because of Memtest86 failure. The RMA replacement kit worked fine. XMP profiles worked fine in both kits and I had no problems with booting the PC if I tried to run the RAM at it's rated speed.
This is my first AMD Ryzen build and I picked the best spec components I could. find.
This is a very simple build with few components on the PC.
I am not keen to do another after this.
..and what u need 4x16GB ram for? I guess most of it will be "stuck n rust" hence never be utilized. I once had 24GB but never got over 16GB.
I have just been contacted by Corsair via support ticket update..
They are unable to do any failure analysis on the first two RMA'd RAM kits.
Therefore I do not know if the RAM was genuinely bad RAM when tested on an intel motherboard or if it simply would not work on the ASUS ROG Crosshair VII HERO (WI-FI) Motherboard I have.
ASUS ROG CROSSHAIR VII HERO (WI-FI) | ROG - Republic Of Gamers | ASUS USA
I have asked Corsair to make improvements to their Corsair Memory Selector as right now the AMD filter still allows selection of RAM which is not supported on AMD 400 series motherboards according to the Corsair Technical Specififcations.
I continue to test the latest Corsair KIt.
I will contact ASUS technical support next.
Started testing attempts to hit 3200 Mhz on the 32GB DRAM kit.
Looking at changing the following.
BCLK set to 100.
Memory Timing Parameters.
DRAM voltage increase from baseline 1.2 Volts.
Will update post with more results as soon as possible.
I set the following Ram Timings, Misc Items, Termination Block Ohms, CAD_BUS Block Ohms, and DRAM Voltage set to 1.35 volts, SOC voltage varied down from 1.2, 1.15, 1.10, 1.05, 1.0 and back up to 1.03125. I also looked at setting Termination Block Ohms and CAD_BUS Block Ohms to Alt1 values.
I discuss the results next.
Specification for Corsair Vengeance RGB PRO 3200 4x16GB Kit shows it was tested at 3200 MHz speed at 1.35 Volts.
Asus automatic overclocking in BIOS had kept DRAM voltage to 1.2 Volts at all Memtest86 passing frequencies up to and including 3150 MHz.
As noted earlier, Asus automatic overclocking in BIOS fails to boot with DRAM frequency target of 3200 MHz unless I increased the SOC voltage.
I note that even then, it still applied DRAM Voltage of 1.2 Volts, and the DRAM timings looked wrong. It failed MemTest86 with a large number of errors.
I decided to only test the DRAM at 3200 MHz using DRAM voltage at 1.35 Volts. That voltage is also suggested by the above DRAM Calculator for Ryzen.
I looked at effect on number of MemTest86 errors with variation of the SOC Voltage from 1.2 ->1.15 -> 1.10->1.05 -> 1.0 volts.
The number of Memtest86 errors (Failing Test 6 and Test 7) decreases as the SOC Voltage is decrease from 1.2 -> 1.05 volts.
Then the Number of errors increase again at 1.0 volts.
The minimum number of errors was found at 1.03125 Volts.