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7820X/R6E AF Memory Detect Error On Boot

idahosurge
Level 7
I built my 7820X / Rampage VI Extreme system in December.

When running the CPU at default settings everything was fine.

I have two of these G.Skill kits for a total of four sticks and 32 GB's of ram.
https://www.newegg.com/Product/Product.aspx?Item=N82E16820232306

Once I changed my BIOS settings to XMP I started to get a AF Memory Detect error on boot, but it did not happen every time. When it happened I just did a hard shut down and rebooted. I also started getting a hard drive detect error on boot at the same time I started getting the AF Memory Detect error, but again it was not every time. I changed the SATA cable and have not had that error since.

After I got the first AF Memory Detect error I loaded System Defaults in the BIOS so any of the XMP settings got erased. I then changed AI Overclock Tuner to Manual and entered the 16-16-16-36 timings manually along with setting the DRAM freq to 3600 MHz with the DRAM voltage at 1.35 for both channels.

I know that the two kits of ram are good because they pass the HCIMemTest stress test as outlined in the ONC.net DDR4 24/7 Memory Stability thread. My system also has zero issues running at 46 /32 with the ram running at 16-16-16-36-1T-tRFC @ 360 @ 3600 MHz. The system has been running like this for over a month.

The kits would not pass HCIMemTest at 15-15-154-35 @ 3600, but they would pass at 16-16-16-36 @ 3600.

With my system overclocked to 46 GHz / 3200 MHz with the ram at 16-16-16-36 @ 3600 MHz I get the AF Memory detect error once every four to 10 days.

I have tried fast boot both enabled and disabled in BIOS. I have tried fast startup in Windows 10 Pro 1709 both enabled and disabled. I have tried R6E BIOS 802 and 1004.

When I first starting getting the AF Memory Detect error I posted and someone said it maybe due to mixing the two ram kits instead of using one kit as recommended for DDR4 so I bought this kit and installed it last Thursday night.
https://www.newegg.com/Product/Product.aspx?Item=N82E16820232585

This kit also passed HCIMemTest with my system overclocked to 46 GHz / 3200 MHz with the ram at 16-16-16-36-1T-tRFC @ 360 @ 3600 MHz and tonight when I turned the system on I got the same dam AF Memory Detect error (4 days after installing) so it has nothing to do with the ram kit.

Does anyone have any idea how to fix this besides trying a different R6E or 78020X?
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15 REPLIES 15

idahosurge
Level 7
A 860W Corsair AX860i.

All other hardware is listed under my PC specs, click on the link above my avatar.

Aufsteiger
Level 7
I have similar errors: BD Memory detect - > no boot.
My MoBo can't boot if my RAM speed is set faster then 3000MHz.

32GB RAM G.Skill 4133 with xmp on R6E, 7980XE

Same here... GSkill 8x8 4000 with or without xmp and manuell Timings - Hangs in detecting ram while Botinnen with more than 3000 mhz.

*but I can remember Running my System at 3600 with older bios.*

IIIGEEIII wrote:
Same here... GSkill 8x8 4000 with or without xmp and manuell Timings - Hangs in detecting ram while Botinnen with more than 3000 mhz.

*but I can remember Running my System at 3600 with older bios.*


I also have the same problem, but I didn't have it for many months. I updated BIOS and have even more problems. So either the mainboard degradates somehow in time or the new BIOS is $%^@#!

To all of you that have problems with RAM running at speeds higher than 3000Mhz. Please check if you have RAM sticks in the slots that are on the right side of the motherboard. In my case, and in case of someone else on this forum, the problems are connected with having RAM on the right side. By putting 4 sticks on the four slots that are on the left, the problem seems to disappear. Unfortunately this does not solve my problem as I have 8 sticks...

If you populate only one side of RAM connectors, you will use at least 2 memory controllers of the cpu, instead of 4, if you populate A, B, C and D banks.
By sure stability is higher when you use only 2 memory controllers. Unfortunately total RAM bandwith is rather the half than using 4 memory controllers.

idahosurge
Level 7
Nothing I tried would fix getting the AF qcode on boot every three or four days.

I finally set my ram timings to 17-18-18-38 instead of their rated timings of 16-16-16-36 and so far it has been working.

I even tried upping my dram voltage on both channels to 1.4, but it only went 9 days before I got the AF Memory Detect qcode again on boot. Also tried 1.41 and it did not even go 2 days.