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Crosshair Hero X670E Refuses Overclock Memory

Level 7

Not sure where else to go at this point but my Hero X670E absolutely, positively, adamantly ******ing REFUSES to allow me to achieve EXPO speeds for my 16x4 memory (Model F5-6000J3040G32GX2-FX5). Hell, I can't even increase my clock speeds by ANY amount, let alone my advertised 5600MHz or my board will refuse to boot until I completely clear CMOS. Hell, I can't even increase CAS latencies without the same problem.


So I'm stuck at 3600MHz unless someone has a magical solution for this ridiculous ******-****** sandwich of a motherboard.


Seriously I've had Pentium 3 boards that were less cursed and more stable than this thing.


Customer Service Agent

Hello, @twiggyd 

May I ask if you have installed memory modules from two different kits, even if they are the same brand and model?
The part number "F5-6000J3040G32GX2-FX5" is not listed in the ROG CROSSHAIR X670E HERO QVL.

We recommend consulting the part numbers listed in the QVL when selecting memory to ensure compatibility and stability.
For further guidance, you can refer to the instructions provided in [Motherboard] How to query (CPU/memory) QVL List? and "purchasing and installation guide" on the official website support page > CPU/Memory Support > Memory / Device Support page.
Please also note that mixing memory modules from different kits is not recommended, as stated:

Ensure that all memory modules are from the same validated memory kit. Do not mix DIMMs from different memory kits—even if they are the same brand and model (e.g., two DIMMs each from two different memory kits). Mixing and matching DIMMs can result in a failure to boot and compatibility issues. In particular, the stability of a system with mixed DIMMs cannot be guaranteed when XMP (Intel)/D.O.C.P (AMD)/EXPO (AMD)/AEMP/AEMPII is enabled.

Furthermore, we suggest consulting the ROG CROSSHAIR X670E HERO user manual to ensure that memory is installed in the recommended slots.

Thank you.

sharing complete hardware info & software config details will help us better understand the issue 🙂

They are two different kits with the same make and model but the issue persists even when only a single kit is installed. I'm now a the point where I am stuck with an error code 15 and the whole system refuses to post.

I wish Asus was more transparent about the lack of memory support, I would never have purchased this board had I known I would have these issues. 

It isn't 1998 and Asus shouldn't be releasing a product this low quality and incompatible, let alone as a higher end board.

1. Combining any kit regardless of make and model is not supported. If you combine memory kits, the overclocked settings in which the kit is validated for XMP/EXPO are no longer valid. This is because memory vendors bin and validate the memory kit in the density in which it is sold. Whether we combine a kit with the same part number, frequency, timings or voltage the advice remains the same.

2. Contrary to assumptions, XMP/EXPO doesn't ensure automatic overclocking. Tighter timings or higher frequencies may require manual adjustments for stability. Overclocking cannot be assured due to variance between parts when run outside manufacture specifications. XMP/EXPO success also depends on the processor's Integrated Memory Controller (IMC) capabilities.

3. Purchasing a kit not present on the vendor QVL will reduce the chances of success.

4. No vendor can or does guarantee overclocking.

5. Q-CODE 15 is a memory training code. With a single kit inserted upon enabling EXPO and rebooting, the process can take 1-2 minutes before completing.


13900KS / 8000 CAS36 / ROG APEX Z790 / ROG TUF RTX 4090