This is another shining example of Asus's crappy software.
The Alteration Mode Switch on the X670E Crosshair Hero only gives you an option between PCI-E Linkspeed and Fan Profile.
Only setting this setting to 'Fan Profile' allows the 7900 XTX to run at Gen 4 x16. Which also means the CPU fan is run at full pelt, since I use a Arctic Liquid Freezer 2 360 AIO... that means the pump is being run full throttle and will likely burn it out very quickly. Since users do not have any control over it at all when Fan profile is selected.
I tried everything last night and the only thing that controls Gen 4 or off for the 7900 XTX?
Is a moronic setting that's still not even detailed in the Bios manual, I kid you not - have a look for yourself.
Screenshot of: E20466_ROG_CROSSHAIR_X670E_Series_BIOS_manual_EM_WEB.pdf
There is no Step 1 or 2 options for either option of 'PCI-E Link Speed' or 'Fan Control'.
Other settings set / tried:
So,after a few hours of running with 'Fan Profile' set as under Alteration Mode... my ears are still ringing and to top it off since the LF2 has a VRM fan... if that bearing goes I will have to replace a AIO as I can't fault Arctic for Asus's b.s software. As the AIO is starting to sound like a pack of hyenas in a blender (Ex-force fans will get that reference haha).
I have decided to unplug the AIO from the motherboard header and plug it into the Corsair Commander Pro. The Commander Pro is being used to control the case fans - both 200mm front intake and rear 120mm exhaust fan using Corsair Link 18.104.22.168.
Tried the version above and I had no control whatsoever and I'm not going to try the latest version as I really don't want to end up doing a clean install to route out all of Corsair's crap either. Sure you could trawl through %Appdata%, %Program Data% but invariably there will be some crap left in the registery under some obscure entries and that will take days of painstaking work. Nah, F that, re-install is a much simpler solution but since 22.214.171.124 has run without issues since September 2019 - if it ain't broke don't fix.
Soo, finally got the PC to boot up with no CPU fan header plugged in. For some bizzare reason the USB header which had the commander pro plugged in was being pinged very late in post as evident by the two LED flashes on the commander pro. Thus the CPU would shut down due to over temperature protection.
Moved the USB 2.0 cable to another USB header on the motherboard, tested various fan configs as FAN1 was not being detected on warm boots. Whereas before I could switch the fan ports around, warm boot and keep testing etc. But now need to shut down per config test. Finally got Fan1 working after various tests.
Set Fan 1 as maximum RPM with a fan connected, tested other fans after every power cycle, Fan 1 still detected. Moved LF2 CPU fan header to Fan 1 whilst on power on state to check if everything ramps to max rpm state.
Test successful, did some quick cable management - had to disconnect the LF2 fan... and reconnected after quick cable management boo FAN1 no longer detected. But Fans and Pump still ramping to max. Cold shut down and put the panels, rear i/o connects back in etc.
Rebooted, everything working fine except... CorsairLink now takes a few seconds to ping fans and load whereas before it was instant. I suspect somewhere in all of this the CorsairLink service has been bumped down in terms of start up sequence.
Confirmed by rapid temp spike to 66 degrees from cold boot 😅. Usually temps don't spike beyond 34-52 degrees C depending on ambient temps (latter is summer ambient temps) and it's winter here so... yeah.
So ****** close... all this could have been avoided if ASUS bothered to test their ****** software properly.
Edit: I forgot... ASUS have the word Da-m.n set as a profanity.... sheesh.
Edit 2: And yes, my 7950X no longer consistently boost beyond 5.4 ghz now. I've managed to get it to randomly spike to 5.7 ~ 5.4 but I'm not sure how much longer I'll be able to plaster a bandaid on their crappy software.
Edit 3: I forgot to mention I have had to set the BIOS to ignore the CPU fan header, CPU temperature has been left as default (still enabled)
Edit 4: Fan Configs - Fan 1: LF2, FAN 2: Top 200MM Intake, Fan 3: Bottom 200MM intake, Fan 6: Exhaust. Seperating out Fan 2 and 3 allows me adjust intake for the M.2s which are directly in the airflow path of Fan 3. Fan 2 is blowing air over the SSDs, which is why they are running pretty darn cold lol at 25~ degrees C. Beats being cooked to death by the M.2 cluster.
Edit 5: For some bizarre reason the Corsair Link Service was now set to manual as opposed to automatic.... set back to automatic.