The official specs says that CROSSHAIR X670E EXTREME supports ECC memory and so does Ryzen 9 7950X. It took a while to find a vendor with DDR5 ECC UDIMMs in stock, but I finally got the Kingston Server Premier DDR5 4800MT/s ECC UDIMMs last week and the system I put together last night doesn’t work.
Relevant parts of the build:
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]Component[/TH]
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]Product[/TH]
|
Motherboard |
ASUS ROG CROSSHAIR X670E EXTREME |
Processor |
AMD Ryzen 9 7950X |
RAM |
Kingston Server Premier DDR5 4800MT/s ECC UDIMM |
Power supply |
CORSAIR AX1600i Digital ATX Power Supply |
With peripherals connected, I observed the following:
- No display output, although the USB-C-to-HDMI dongle LED is on.
- USB optical mouse laser is off (no power).
- USB keyboard LEDs are off (no power).
- Front panel USB-C port can charge my phone.
Q-Codes observed during startup with the DIMMs in slots A2, B2, A2 + B2, or all the slots:
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]Q-Code[/TH]
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]Meaning[/TH]
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]Duration[/TH]
|
00 |
Not used |
Split second |
C1 |
(unknown; not in MB documentation’s Q-Code table) |
Split second |
46 |
(unknown; not in MB documentation’s Q-Code table) |
Split second |
91 |
Driver connecting is started |
Split second |
00 |
Not used |
Split second |
15 |
Pre-memory System Agent initialization is started |
60 seconds |
00 |
Not used |
Split second |
CC |
(unknown; not in MB documentation’s Q-Code table) |
Split second |
00 |
Not used |
Split second |
00 |
Not used |
Split second |
99 |
Super IO initialization |
Final state (forever) |
I checked ASUS’
general troubleshooting page (Intel-specific rows removed):
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]AMD Motherboard Q-Codes[/TH]
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]CPU abnormal[/TH]
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]Memory abnormal[/TH]
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]Graphic Card abnormal[/TH]
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]Others abnormal[/TH]
|
F9 |
|
✔️ |
|
|
B0, 99, 15, 53 |
✔️� |
✔️ |
|
|
D6 |
|
✔️ |
|
|
00, 19, 30, 40, 55 |
✔️ |
✔️ |
✔️ |
|
A0, A2 |
|
|
|
Boot up device abnormal |
B2 |
|
|
|
External device abnormal |
A9 |
|
|
|
Boot into the BIOS |
AA |
|
|
|
Boot into the system |
It seems like I should focus on either CPU or memory.
I’ve already attempted these troubleshooting steps:
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]Component[/TH]
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]Action[/TH]
[TH="class: _3TNkDptlyGOiWXvdX_acOB"]Result[/TH]
|
PSU |
Connect all the connectors. |
Already double-checked that they were all connected. |
CPU |
Check for dirt |
This what what I did before putting the CPU in. |
CPU |
Check for broken pins (not applicable to AM5 CPUs now, but applicable to the MD socket) |
I took the fan and heatsink off and removed the CPU to inspect the pins in motherboard CPU socket. They look fine to me. |
RAM |
Check for dirt |
Already vacuumed the motherboard and inspected the RAM modules themselves. |
RAM |
Try the different configurations. |
Slots A2 and B2 alone or together and all four slots exhibit the behavior I described. Using either slots A1 or B1, though, result in a Q-Code C5, which is not documented, but they also non-recommended memory configurations. And just for completeness, no RAM modules installed results in a near-instantaneous Q-Code of 10 (PEI Core is started). |
Peripherals |
Remove all peripherals. |
Already tried with and without. |
|
Clear the CMOS. |
No changes to symptoms. |
|
Switch BIOS (on dual-BIOS boards). |
No changes to symptoms. |
From Googling Q-Code 99-related issues,
one commenter noted that it’s probably storage-related. But installing the PCIe 5.0 M.2 adapter (which comes with the motherboard) with a stick of memory didn’t change the outcome.
I plan to substitute the RAM kit next. I already have a RAM kit on the motherboard’s QVL in my shopping cart (CORSAIR CMT32GX5M2B6000Z30K) which can ship in a few days and would still be within my RMA period. If that doesn’t work, I’m not sure what to do.
If RAM incompatibility is the real problem, is there any expectation of RAM support being expanded with new BIOS updates? There is
a post about a similar issue on a different forum and about different motherboard manufacturer, but it mentions that:
I had to update the BIOS from 1.03 to 1.09 for it to POST with the new RAM.
Edit: added BIOS note
