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QCode AF Detect Memory & PC will not boot every time with Ram above 3200 MHz

idahosurge
Level 7
Since I built my system in December every two days to 14 days I get QCode AF Detect Memory on boot. Please understand that when the system boots all the way into Windows 10 the system is perfectly stable and passes HCI Memtest and x264. The problem is just getting the QCode on boot, there is no problem once the system boots into Win10.

Rather than go through all the voltages I have tried, what ram I have, etc. please see this thread.
https://rog.asus.com/forum/showthread.php?100005-7820X-R6E-AF-Memory-Detect-Error-On-Boot

In the past two months I have finally figured out that this QCode error on boot is related to the frequency that I have my ram set at.

If my ram is set at 3200 MHz or below I never get this code. Setting my ram at 3400 MHz or 3600 MHz I get the error on boot. I get this error with my ram set at C16 or C17 and even when the DRAM voltage on both channels is set to 1.40.

I have also tried BIOS 802, 1004 and 1301. Still get the QCode on boot.

So whatever test is being ran during boot will throw this QCode when the ram is set above 3200 MHz. Does anyone know what could be causing this or how I can fix it?

In BIOS under Dram Timings will disabling Dram Training and/or Attempt Fast Boot and/or Attempt Fast Cold Boot help? I do not want to disable these to see if it will make a difference without getting some advise first.
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12 REPLIES 12

G75rog
Level 10
My Apex RAM is set to 3466 and it will hang once in a while if the computer is cold. After it is powered on for a minute it boots normally. Not worth tracking down.

G75rog wrote:
My Apex RAM is set to 3466 and it will hang once in a while if the computer is cold. After it is powered on for a minute it boots normally. Not worth tracking down.


When I run my ram at the kits rated 16-16-16-36 @ 3600 MHz I get this QCode on boot every two to three days so for me it is worth trying to figure out what will fix it.

CSN7
Level 7
You can try reseating the CPU. I once didn't screw the CPU cooler on tight enough and it would occasionally not detect memory channels. The CPU needs lots of preassure to be propperly pressed down into the socket.

CSN7 wrote:
You can try reseating the CPU. I once didn't screw the CPU cooler on tight enough and it would occasionally not detect memory channels. The CPU needs lots of preassure to be propperly pressed down into the socket.


I already tried this and no change.

Silent_Scone
Super Moderator
idahosurge wrote:
Since I built my system in December every two days to 14 days I get QCode AF Detect Memory on boot. Please understand that when the system boots all the way into Windows 10 the system is perfectly stable and passes HCI Memtest and x264. The problem is just getting the QCode on boot, there is no problem once the system boots into Win10.

Rather than go through all the voltages I have tried, what ram I have, etc. please see this thread.
https://rog.asus.com/forum/showthread.php?100005-7820X-R6E-AF-Memory-Detect-Error-On-Boot

In the past two months I have finally figured out that this QCode error on boot is related to the frequency that I have my ram set at.

If my ram is set at 3200 MHz or below I never get this code. Setting my ram at 3400 MHz or 3600 MHz I get the error on boot. I get this error with my ram set at C16 or C17 and even when the DRAM voltage on both channels is set to 1.40.

I have also tried BIOS 802, 1004 and 1301. Still get the QCode on boot.

So whatever test is being ran during boot will throw this QCode when the ram is set above 3200 MHz. Does anyone know what could be causing this or how I can fix it?

In BIOS under Dram Timings will disabling Dram Training and/or Attempt Fast Boot and/or Attempt Fast Cold Boot help? I do not want to disable these to see if it will make a difference without getting some advise first.


Hi, hanging on QCODE AF in this instance sounds like memory instability. You will need to tune the memory related settings to consistantly pass memory training. Alternatively, you can enable MRC Fast Boot from within the UEFI which will disable POST stress tests, however, this can sometimes result in instability at OS level depending on how conditional the overclock is.

G75rog wrote:
My Apex RAM is set to 3466 and it will hang once in a while if the computer is cold. After it is powered on for a minute it boots normally. Not worth tracking down.


Again, memory instability. If POST fails once in a blue moon, then it shouldn't be too difficult to dial out.
13900KS / 8000 CAS36 / ROG APEX Z790 / ROG TUF RTX 4090

Silent Scone@ASUS wrote:
Alternatively, you can enable MRC Fast Boot from within the UEFI which will disable POST stress tests, however, this can sometimes result in instability at OS level depending on how conditional the overclock is.


Can you tell me where "MRC Fast Boot" is in the R6E UEFI?

Under "DRAM Timing Control" I have "Attempt Fast Boot" and "Attempt Fast Cold Boot". Under "DRAM Timing Control" I also have"DRAM Training".

Under "Boot Menu" I have "Fast Boot".

I do not see "MRC Fast Boot" anywhere.

Silent_Scone
Super Moderator
Hi, enable Attempt Fast Cold Boot.
13900KS / 8000 CAS36 / ROG APEX Z790 / ROG TUF RTX 4090

Silent Scone@ASUS wrote:
Hi, enable Attempt Fast Cold Boot.


Thanks!

Abaidor
Level 9
I used to have it on the Rampage VIE with 64GB Trident Z RGB 3600 CL17 XMP Enabled. I increased dram voltage to 1.39 and played with CPU System Agent voltages | VCCIO along with DIGI+ Dram to 140% and it went away.

I also have enabled the fast boot options. It still shows up occasionally though but not so frequently since I am 99% putting the PC to sleep instead of shutting down.

It passes Memetest and have not issues with memory crashes.
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