8700k struggles at 5.1 Ghz. Insufficient CPU strength or faulty component?
8700k struggles at 5.1 Ghz. Insufficient CPU strength or faulty component?
Hello everyone,
I’m sharing my experience with an overclocked i7 8700K running at 5.1 Ghz across all cores, using a 1.34 Vcore. The stress test I ran with Prime95 version 26.6 (non-AVX) for eight hours showed no crashes, and the temperatures stayed below 65°C. This was thanks to the chip being delidded and using the EVGA 280mm CLC motherboard. It felt quite stable.
However, when I attempted to push it to 5.2 Ghz, even increasing the Vcore didn’t prevent crashes or BSODs within about 5 to 10 minutes. I tested a range from 1.346 Vcore up to 1.40 Vcore, but the temperature remained normal, suggesting thermal throttling wasn’t the issue.
I’m wondering if this performance drop is related to the chip’s inherent limits at 5.1 Ghz, or if it’s connected to insufficient CPU power. My Z370 motherboard only has an 8-pin CPU_PWR connector, whereas my Z390 model usually has an 8-pin plus a separate 4-pin CPU_PWR connector. Could the 8-pin connector provide enough power for the i7 8700K at those higher frequencies?
Details:
- i7 8700K
- 32 GB RAM
- RTX 2080
- EVGA G2 850W
- MSI Z370 A-pro board
people usually think i9 9900k is the path to reaching 5 ghz. but it looks like you'll need to wait for the next generation models if you want to go even higher than that.
why do you think you should reach well beyond 5 ghz. most reviews say the i9 9900k is the path to 5 ghz. it looks like you'll need to wait for their tenth and eleventh generations if you want to go much higher. I own an i7 8700k :
You can achieve a solid 5.1 with all-core at 1.34v using a good chip. Only the highest binned CPUs will maintain stability at 5.2 or 5.3 across different voltages. Above a certain point, performance drops sharply when overclocking. Gaining that extra speed factor demands huge voltage and temperature boosts. The exact threshold varies per CPU. LLC also helps manage voltage droop. I recently sold my delidded 8700k, which needed 1.385v to run at 5.0Ghz all-core.
8700Ks at 5.2-5.4 GHz represent highly optimized chips with custom loop cooling, where reduced silicon trace resistance enables higher clock speeds at the same voltage or even safer voltages. Achieving 5.1 GHz on an AIO with six cores is seen as a rare success. Overclocking isn't guaranteed, and some users may not reach 5.0 GHz. Consider your +1.5 GHz overclock as sufficient. Expect bigger improvements from increasing RAM, Uncore (Ring), and GPU starting here. Have a good day.
Thank you for your responses. It was somewhat frustrating because the chip managed 5.1 GHZ at 1.34 vcore and 65C under full load, yet it still couldn’t reach an additional 100 MHz by increasing the voltage to 1.40 vcore. I think the device has reached that performance limit. It’s reassuring to know the issue was caused by the chip itself, not a lack of CPU power from the motherboard. That was my biggest worry because having a high-end chip designed for 5.2 GHz or more would be disappointing if it couldn’t keep up due to insufficient CPU strength.
On another note, my new motherboard—MSI Z390 MPG Gaming Pro Carbon AC (with 8pin and extra 4pin CPU power connector)—will arrive this Friday. I’ll let everyone know if anything remarkable happens. If not, I’m still satisfied because a better VRM heatsink will always be beneficial.