Just installed a Z790 Classified Mother board in my pc . running a 12900kf cpu. the pc takes forever to boot i get several post beeps and the screen has - and lower down 98 on it when it boots until the 790 logo appears. Did a fresh install of windows which was a struggle. currently running team group t force ram 7800mhz but pc wont run unless i leave it at the default speed ( 4400 ). Flashed bios to 1.11 up dated windows. called tech support and the person i spoke with suggested raising ram voltage. did that and pc wouldn't boot had to reset cmos.I was wondering if any one here more savy than myself has any suggestions to fix stated issues? I ordered a set of 600mhz corsair ram  to see if that fixes issues. Any suggestions would be appreciated
 

Sajin
The 12900kf only supports up to 4800MHz officially for DDR5 even though you may be able to get higher speeds than that when overclocking. Higher speeds than 4800 isn't guaranteed though as you're overclocking. Adjusting ram voltage, and cpu imc voltage to obtain/stabilize your desired frequency will be needed, and in some cases may not help if your cpu imc isn't up to the task.

I didn't know that.

DDR5 only OCs well in 2 sticks. 4 sticks is not supported for OC and is luck base.

I used G.Skill Trident ram on my z690, was suggested ram on forums and from digging around on markets has highest speeds.

If only on 2 sticks,
Update bios
Finish your windows updates
Install your mobo drivers
Install your video drivers
Finalize all your 1st time PC stuff.

Put in for a return on the Ram,
Order a better set.

If you needed 4 sticks to have enough Ram, bear in mind....memory controller only supports 128. We can purchase 2x48 gig ram kit right now. That is 92gigs in 2 slots!
No reason to do 4 dimm slots in ddr5.

My g.skills would not overclock till I got my bios updated. Board came with stock bios.
Dark Kingpin z690 with 12900k.

Used XMP profile in bios was easy.
Memory training is slow when making change.

I am glad to hear that you found a resolution to the concern.  Please do not hesitate to contact us at Support@EVGA.com if you should need any additional information or support with your EVGA products.
 

deunan48
I bought some corsair 6000Mhz that i am running and returned the 7800Mhz to new egg . The 6k is stable and boots quickly now. I had to RMA the board for other reasons and unless i left the default timings on it wen i put in the 7800 it was an immediate blue screen. I am running a single kit of 2 sticks (2x 16Gb ). I know about the 4 stick issues so i only went with a single kit.