Overclocking an i7-8700K using an AORUS Z390 Master motherboard
Overclocking an i7-8700K using an AORUS Z390 Master motherboard
Hi there,
I just bought the Aorus z390 mainboard to boost my i7 8700K. My old ASUS Prime z370-P wasn’t ideal for an overclocked setup. I plan to install it tomorrow.
I need to run the system every day at 5GHz, since Prepar3d with many add-ons only works smoothly in overclock mode.
I searched online for guides, but none matched my setup—only those for Intel 9th Gen CPUs. I’m worried I might damage my CPU if I follow these instructions.
As mentioned, I have an i7 8700K (delidded).
My power supply is a quiet Be Quiet! Dark Power 11 650W 80+ Platinum. I think that’s sufficient.
The mainboard I’m considering is the AORUS Z390 Master.
Graphics: RTX 2060 (6GB)
RAM: 16Gb DDR4 at 1500MHz
It would be really useful if someone could share the BIOS settings I should adjust.
I’m seeking advice because I only know the basics of overclocking and don’t want to risk harming my CPU or board.
If you have any other information, please let me know!
Thank you for reading, and I hope you can help!
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CPU overclocking guide for newcomers
Explains the fundamentals. If you're here, chances are you're seeking assistance with simple overclocking or want to revisit any lessons that might have been missed. You're welcome—this is meant to be...
Thank you for your answer Darkbreeze, but I'm having trouble getting stable! I adjusted to 5GHz and began from 1.3V until I reached 1.37V, but I keep failing the Prime95 test every time. Now it's down to 4.9GHz with 1.3V and still fails. The LLC is set to Turbo mode. It also restarts at idle automatically with event ID 41 cat:63. My power supply is very good, and I've increased the OC key on the be quiet! power supply. I connected it to all the 12-pin CPU power pins—two 8-pin connectors on the motherboard. I'm unsure if this affects stability, thinking it might stress the board or CPU. There are only guides for i9 9XXX models, not for the i7 8700K, so I can't find any relevant advice for my system. I don't know what's going wrong. I've spent a lot of money, but it doesn't work smoothly as I expected!
I believe I've discovered a fix.
I adjusted AVX to 3 and turned off the turbo mode. I also increased the voltage for both long and short durations to their maximum settings.
Initially, I tried 5ghz and 1.31V, but Prime95 ran smoothly for around 20 minutes without any issues.
CPU temperatures stayed around 86°C with a delta of max temperature.
The core speed reached 4.7ghz thanks to AVX.
Once stability was confirmed for about 30 minutes, I plan to deactivate AVX and test if it remains stable at roughly 1.33V.
Without AVX I don't meet the prime test at any core volt settings. However, I stabilized the core frequency at 5GHz and AVX at 1 with 1.33v. The maximum temperature is around 90°C. I just passed the 36K self-test of prime95, which seems to be satisfactory. I'm curious if I can adjust these settings to 1.325V.
Not all chips perform well at 5Ghz. It might be better to begin again around 4.5Ghz and gradually increase. If you hit a plateau at 4.7Ghz, that’s likely the limit. At 4.9Ghz, that’s probably the maximum for your chip. There’s a reason it’s often called the Silicon lottery. Temperatures are critical—90°C is too high, and 81°C is even worse. If you can’t keep the temperature below 80°C, using Prime95 version 29.6 with AVX and AVX2 disabled, as I mentioned before, suggests either your chip isn’t suited for that clock speed, or your cooling isn’t sufficient. This could be due to a poor CPU cooler, insufficient case airflow, or excessive core voltage. If cooling is fine but you can’t lower the core voltage without instability, then your chip likely can’t reach that frequency. Other factors might also play a role, such as an inadequate motherboard for stable power delivery, too many fast DIMMs with high voltage, or some other issue that needs adjustment. In short, don’t start at 5Ghz—begin lower and progress carefully.
Hello Darkbreeze, thank you for your reply!
I believe the system is now stable at 5GHz with AVX enabled at 1 (4.9GHz).
However, when I have some free time, I plan to turn off AVX and test at 4.5 GHz to check further improvements.
After work, I’ll share 4 pictures from Cinebench 15 and 20—one during the test and one once it’s done.
Appreciate your support!