Asus Z790-F XMP problems.

[phyxsius]

I've this issue going on since I built this PC. When I activate XMP profile. System goes bye bye. 

RAM installed on A2 and B2 as Asus suggests. Default XMP profile boosts up the RAM freq to 7800mhz. System boots ok. However, let alone gaming, even Chrome crashes constantly. Access Violation. Alternative XMP profiles result just the same.

Down clocking to 7600mhz delays crashing a little bit but not fully.
Down clocking to 7200mhz makes it more stable but after high loads result just the same. ( Video encoding, more than one game launched same time, CPU or GPU based rendering etc. )
Anything between 7200 and the default clock 4800mhz result boot loop.
default clock 4800mhz runs without any problems.

I've tried:
fine tuning timings and voltages. Bios updated to latest 31/03/2023. 
Remounting dimms after adjusting.
Different Slots.
Single dimm

I would really appreciate any suggestions on how to make it work so I can get what I've paid for.

Here are the gear that I use:
Windows 11
Asus ROG Strix Z790-F Gaming WiFi Intel Z790
Intel i9 13900k
G.Skill 32GB(2x16) Trident Z5 RGB 7800mhz CL36 DDR5 Ram (F5-7800J3646H16GX2-TZ5RK) 
Asus 1200W Rog Thor 1200W Platinum II 
ASUS GEFORCE RTX 4070 TI ROG-STRIX
ASUS ROG RYUO III 360
ASUS Rog Strix Gx601 Helios

[phyxsius]

@andino thank you for your comments and suggestion. I'm a software developer whom exhausted with work and don't have much time to dig into these type of research. I, as a regular user, expect the hardware that I've bought matches what is advertised. Shame. I should not be forced to get my hands dirty.

[andino]

I agree.. When I think of XMP and speed I think of it as a setting that allows advertised speeds. Also, if your ram is on Asus's QVL then it should work. You shouldn't have to go to the ram manufacturer and see if they have the MB as well. Asus should take care of that and either get support back for it or remove it from the list. Little bit of background, I have a z790 Hero and a GSkill kit that was on both lists and the GSkill delisted Asus. Now the only MB that is listed for the ram that I bought is the Apex.  Also had an Asus x670e Extreme AM5 setup that had EXPO issues. Got a refund for it and went to another brand and the EXPO worked out of the box. Strange....

I think that there has been a cutback of staff at Asus BIOS department in the last few years. They used to keep adding memory to their QVL with BIOS updates. Now it seems like the BIOS updates are more infrequent and the updates are few and far between. It was my understanding from other places that they have reduced staffing for BIOS updates. This might be the reason that the XMP updates aren't happening.

Either way, there are some really good tutorials out there that show you how to manually set the ram timings so that they function at advertised speeds. 

Also, I think that someone in the BIOS department needs to go and read those tutorials so that XMP works. I'd much rather click an option in BIOS and get the advertised speed than fiddle with the motherboard for hours... 

[phyxsius]

@andino Gosh. I wish I would be offered refund. I would be really appreciated I you can refer me to one of those tutorials that you have mentioned because those I've found were somewhat useless.

[andino]

(57) Actually Hardcore Overclocking - YouTube 

I've watched a few of his DDR5 videos. Also hit up Reddit and Overclock.net for advice. 

Google your MB model name 'DDR5 timing' and your kits model numbers and you'll get a good head start.

Everyone has a favorite place to look but for starting out the Actually Hardcore youtube channel is a good start.

Good luck!