Yeah since 1st gen, Ryzen prefers even CAS timings.
Above 2666 usually the odd CL you set will round up to closest even number with Geardown mode enabled and 1T.
Disabling GDM will allow you to run at odd CL and 2T.

CPU temperatures & power draws...

Realbench v2.56 (15 mins) - CPU Temperature

CPU	Idle (°C)	Load (°C)
10900K @ 5.1 GHz All-Core	40.9	89.4
5900X @ 4.5 GHz All-Core	44.8	88.6
5900X @ CO -30/25 +200 MHz	44.0	91.5

Realbench v2.56 (15 mins) - CPU Package Power

CPU	Idle (W)	Load (W)
10900K @ 5.1 GHz All-Core	29.5	210.2
5900X @ 4.5 GHz All-Core	63.4	209.0
5900X @ CO -30/25 +200 MHz	37.3	221.6

Realbench v2.56 (15 mins) - Total System Power Consumption (CPU+GPU+etc)

CPU	Idle (W)	Load (W)
10900K @ 5.1 GHz All-Core	132.0	744.0
5900X @ 4.5 GHz All-Core	144.0	692.0
5900X @ CO -30/25 +200 MHz	116.0	704.0

Battlefield V (10 mins) - CPU Temperature

CPU	Idle (°C)	Load (°C)
10900K @ 5.1 GHz All-Core	40.3	73.5
5900X @ 4.5 GHz All-Core	44.8	71.3
5900X @ CO -30/25 +200 MHz	44.8	77.0

Battlefield V (10 mins) - Total System Power Consumption (CPU+GPU+etc)

CPU	Idle (W)	Load (W)
10900K @ 5.1 GHz All-Core	132.0	596.0
5900X @ 4.5 GHz All-Core	148.0	556.0
5900X @ CO -30/25 +200 MHz	124.0	564.0

My setups:
10900K @ 5.1 GHz All-Core: vCore auto | LLC6 | SVID Trained | C-state off
5900X @ 4.5 GHz All-Core: vCore BIOS set 1.35v | LLC auto | C-state off
5900X @ @ CO -30/25 +200 MHz: PBO Mobo | CO - ve 25,25,25,25,25,25,30,30,30,25,30,25 | OCOV +200MHz| C-state off
Custom WC: by EK-Supremacy EVO RGB + 2x RX360 + 12x GT + 1x D5
ROG Strix B550-I, BIOS 2007 | Maximus XII FORMULA, BIOS 2005
2x16GB TridentZ Royal 4000C17 B-die @ 3800 14-15-15-28, cooled by 2x 60mm fans
TUF 3080 BIOS V2, OC +150/1100 | driver 461.81
AX1200i (digital power draw monitoring)
Dimastech EasyDual V2.5
Ambient 30C A/C off

This post has been edited by owikh84: Apr 24 2021, 10:11 AM

ROG CROSSHAIR VIII / STRIX B550 latest AGESA BIOS

1. Improved system stability
2. Update AGESA ComboV2PI 1203_PatchA

📌 ROG CROSSHAIR VIII HERO 3601 BETA BIOS
https://drive.google.com/file/d/1s7ITDqsxVi...iew?usp=sharing

📌 ROG CROSSHAIR VIII HERO WI-FI 3601 BETA BIOS
https://drive.google.com/file/d/1FNA1_zB4B_...iew?usp=sharing

📌 ROG CROSSHAIR VIII FORMULA 3601 BETA BIOS
https://drive.google.com/file/d/1PZ9cmIvzjo...iew?usp=sharing

📌 ROG CROSSHAIR VIII IMPACT 3601 BETA BIOS
https://drive.google.com/file/d/1-59vYb8eQW...iew?usp=sharing

📌 ROG CROSSHAIR VIII DARK HERO 3601 BETA BIOS
https://drive.google.com/file/d/16vu2oIqmxY...iew?usp=sharing

📌 ROG STRIX B550-F WI-FI GAMING 2401 BETA BIOS
https://drive.google.com/file/d/1ezZ7BGFbc7...iew?usp=sharing

📌 ROG STRIX B550-E GAMING 2401 BETA BIOS
https://drive.google.com/file/d/1Byddq-15gh...iew?usp=sharing

📌 ROG STRIX B550-I GAMING 2401 BETA BIOS
https://drive.google.com/file/d/1LVy2Uwtx80...iew?usp=sharing

📌 ROG STRIX B550-XE GAMING WI-FI 2401 BETA BIOS
https://drive.google.com/file/d/1UTrYxR8f12...iew?usp=sharing

MSI X570/B550 New AGESA BIOS

1. Improved system performance
2. Update AGESA ComboV2PI 1203_PatchA
3. Added support for Ryzen 5000G APU

▪️MSI MEG X570 GODLIKE
▪️MSI MEG X570 ACE
▪️MSI MEG X570 UNIFY
▪️MSI MEG B550 UNIFY
▪️MSI MEG B550 UNIFY-X
▪️MSI MAG B550M MORTAR
▪️MSI MAG B550M MORTAR WIFI
▪️MSI MAG B550 TOMAHAWK

BETA BIOS DL：
https://drive.google.com/drive/folders/16uL...bnF?usp=sharing

For OC I always prefer boards that come with a debug LED for ease of error troubleshooting.

MSI X570 Unify or ACE
ASUS ROG Strix X570-E WI-FI

Unify is a solid board for OC, but if you want better performance efficiency then go for ASUS.
Nice VRM temp, high resale value and constant BIOS support.

Anyone tried the latest ClockTuner 2.1 RC5 already?
I recently tested the PX, P1 and P2 profiles recommended by the software. CB R20 results as below:

Cinebench R20

CPU	MC (cb)	SC (cb)
5900X @ CO -30/25 +200 MHz	8922	622
5900X @ CTR PX	7780	624
5900X @ CTR P1	8733	584
5900X @ CTR P2	8972	600

From my results, CTR P2 profile yields slightly better result than my curve optimizer method in terms of MT score (+0.6%) but lower by -3.5% in ST performance.
However, CTR PX profile gave the best ST score while registering the lowest MT score.
In conclusion, I still think that my CO still have the advantage in perfect balance of MT and ST performances.

My setup:
CPU: 5900X
CO: PBO Mobo | Per Core - ve 25,25,25,25,25,25,30,30,30,25,30,25 | OCOV +200MHz| C-state off
MB: ROG Strix B550-I, BIOS 3401
RAM: 2x16GB Klevv CRAS XR RGB 3600C18 DJR DR @ 3800 16-21-20-32-1T @ 1.40v | IF 1900 Synced
GPU: TUF 3080 BIOS V5, OC +150/1100 | driver 466.63
SSD: WD SN850 1TB + Crucial MX500 2TB
PSU: CM V850 SFX
Cooler: EK-AIO D-RGB 360mm + 6x EK Vardar-S 120 Fans
Case: Jonsplus i100 Pro

Still OCing but more active in other forums LOL