Thanks to Asus ROG
C8F with 3600X and 3900X.
Safedisks ROG Crosshair VIII LN2 OC Guide
https://community.hwbot.org/topic/19...-ln2-oc-guide/
LN2 BIOS
ROG CROSSHAIR VIII FORMULA / HERO 0042 BIOS
FORMULA : https://bit.ly/32fMVrz
HERO : https://bit.ly/2NGkM9X
ROG CROSSHAIR VIII FORMULA / HERO 0090 BIOS (but LN2 cbb)
FORMULA : https://bit.ly/2LI2cf6
HERO : https://bit.ly/2JlUMMO
OCPACK
Download : https://bit.ly/2XyAtVt
MemTweakit : https://www.dropbox.com/s/8jjzqgdxc9...8phIoLtExuGzBc
CCX Overclock Tools
Can specify the VID you want: https://www.dropbox.com/s/eh69lsrtxxp5gum/PCCX.rar?dl=0
Smaller version. Run perccx.exe as admin: https://www.dropbox.com/s/s6hx5sipep...x0723.rar?dl=0
GB3 and CB15 boost
https://www.dropbox.com/s/gwemgm4u2j...zHq2cGzc9YpGXo
After loading GB or CB bench then run the boost, just click defaults button after benching to prevent bsod
LN2 OC TIP
There is an FCLK cold bug under LN2 so try to stay around 1400~1600 for FCLK under LN2 to get a good compromise between temps and perf.
To improve stability in this case:
VDDG 1.15v, SOC 1.28v, disable DF Cstates.
Depending on the CPU and FCLK, may have to control temps -120C ~ -170C.
Do not be alarmed when it resets when temperature changes, pcie and fclk needs to retrain when temps change. Also sometimes there is temperature hole so going lower than it hangs may help.
FCLK
Biggest problem on the platform. 1200 default freq and supposed to go 1:1 with memory for best latency.
Improves performance but limited, ~ 1800+ on air and 1400 on LN2.
FCLK instability includes hang at postcodes such as ?07?, stuttering in OS, drop performance in Cinebench.
CPU has FCLK cold bug.
Improve FCLK Margin by using 1.15VDDG (too much will hang) and 1.3+v SOC. Since VDDG is sourced from SOC so SOC should be higher. VDDG only takes effect at 1400+ FCLK so under LN2 you need to set 1400. Higher usually fails during LN2.
Enable LN2 mode, Use the Load LN2 profile as a base template, this uses low vcore so you can save exit when it?s not cold. You will need to do this before -40C to avoid cold bug. You need 1400 FCLK + 1.15v VDDG and 1.35~1.45VSOC.
About AMD Limitations
Safemode cannot restore back to stock memory settings as this takes place in the ?PSP? which the BIOS has no control over at that point of time. Either you have to clear cmos or wait for 5 times of post code ?F9? to get into AMD?s recovery mode. AMD?s recovery mode restores every AMD option back to stock, including timings and CLDO voltages.
Because of the above, try not to clear cmos during LN2, at most go safe mode if your settings can be sustained with 1.5v DRAM, since BIOS will apply 1.5v for safemode when LN2 enable. IF you clear cmos, FCLK will go back to Auto and CLDO VDDG voltage will too. When cold, FCLK needs to be 1400+ and VDDG 1.15v if not Fabric will be unstable so you need to torch up to maybe -60c in this case. Therefore test your Memory settings on ambient first. Cold CPU improves Memory OC so you don?t need to worry about MC cold bug.
TRY NOT TO CLEAR CMOS WHEN CPU IS COLD
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