F5F Stay Refreshed Power Users Overclocking i7-6700K doesn't hold 4.5 GHz

i7-6700K doesn't hold 4.5 GHz

i7-6700K doesn't hold 4.5 GHz

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mj18wals
Senior Member
256
05-27-2016, 07:09 AM
#1
Hello,
I’m experiencing a problem with my i7-6700K. After overclocking it to 4.5 GHz while turning off Intel Turbo Boost and setting the voltage to 1.35V, I encountered issues during stress tests like Prime95 or OCCT. The processor fails to maintain 4.5 GHz consistently—it sometimes drops to 4.3 GHz or 4.0 GHz. Although temperatures stay within normal ranges (under 65°C in high load), the performance doesn’t meet expectations. The tests show no errors, but I’m curious why it doesn’t hold at full speed in professional stress scenarios, unlike in 3Dmark. My setup includes an MSI Gaming Pro motherboard, 850W power supply, and 3200 MHz DDR4 RAM (currently underclocked to 2400 MHz). I could manually set the CPU clock to 4.5 GHz without using Intel EIST, but I’d rather keep the CPU idle when not in use.

Thank you for your help.
Benjamin.
M
mj18wals
05-27-2016, 07:09 AM #1

Hello,
I’m experiencing a problem with my i7-6700K. After overclocking it to 4.5 GHz while turning off Intel Turbo Boost and setting the voltage to 1.35V, I encountered issues during stress tests like Prime95 or OCCT. The processor fails to maintain 4.5 GHz consistently—it sometimes drops to 4.3 GHz or 4.0 GHz. Although temperatures stay within normal ranges (under 65°C in high load), the performance doesn’t meet expectations. The tests show no errors, but I’m curious why it doesn’t hold at full speed in professional stress scenarios, unlike in 3Dmark. My setup includes an MSI Gaming Pro motherboard, 850W power supply, and 3200 MHz DDR4 RAM (currently underclocked to 2400 MHz). I could manually set the CPU clock to 4.5 GHz without using Intel EIST, but I’d rather keep the CPU idle when not in use.

Thank you for your help.
Benjamin.

L
LarsMatena
Senior Member
602
05-27-2016, 02:45 PM
#2
Benjamin Barrois:
Hello,
I’m experiencing a problem with my i7-6700K. When I overclock it to 4.5 GHz, turning off Intel Turbo Boost and setting the voltage to 1.35V, the processor fails to maintain that speed during stress tests like Prime 95 or OCCT. It sometimes drops to 4.3 GHz or 4.0 GHz instead. The temperatures stay within normal ranges, below 65°C even under heavy load. I’m unsure why it doesn’t reach 4.5 GHz in professional stress tests, while it does in 3Dmark. Any suggestions?
I have an MSI Gaming Pro motherboard, 850W power supply, and 3200 MHz DDR4 RAM (underclocked at 2400 MHz). I could try forcing the CPU speed higher if needed.
L
LarsMatena
05-27-2016, 02:45 PM #2

Benjamin Barrois:
Hello,
I’m experiencing a problem with my i7-6700K. When I overclock it to 4.5 GHz, turning off Intel Turbo Boost and setting the voltage to 1.35V, the processor fails to maintain that speed during stress tests like Prime 95 or OCCT. It sometimes drops to 4.3 GHz or 4.0 GHz instead. The temperatures stay within normal ranges, below 65°C even under heavy load. I’m unsure why it doesn’t reach 4.5 GHz in professional stress tests, while it does in 3Dmark. Any suggestions?
I have an MSI Gaming Pro motherboard, 850W power supply, and 3200 MHz DDR4 RAM (underclocked at 2400 MHz). I could try forcing the CPU speed higher if needed.

D
DonMcOne
Member
188
05-28-2016, 10:04 PM
#3
Benjamin Barrois:
Hello,
I’m experiencing a problem with my i7-6700K. When I overclock it to 4.5 GHz, turning off Intel Turbo Boost and setting the voltage to 1.35V (I could go even lower but need more testing), during Prime 95 stress test or OCCT the processor fails to maintain 4.5 GHz. It sometimes settles at 4.3 GHz, other times at 4.0 GHz... The temperatures remain normal, below 65°C under high load.

Tests indicate no errors, so it seems stable, but I’m curious why the CPU doesn’t reach 4.5 GHz in professional stress tests, while it does in 3Dmark CPU stress test. My motherboard is MSI Gaming Pro, has an 850W power supply, and 3200 MHz DDR4 RAM (underclocked to 2400 MHz if needed). I could try forcing the CPU clock to 4.5 GHz without enabling Intel EIST, but I’d rather keep the CPU idle when not in use.

Any suggestions?
I don’t run Prime95, but maybe at certain times the CPU isn’t fully utilized and EIST allows the frequency to drop. Trying Prime95 with EIST disabled might confirm if the frequency stays at 4.5 GHz. If it does, I’d assume everything is working correctly.
D
DonMcOne
05-28-2016, 10:04 PM #3

Benjamin Barrois:
Hello,
I’m experiencing a problem with my i7-6700K. When I overclock it to 4.5 GHz, turning off Intel Turbo Boost and setting the voltage to 1.35V (I could go even lower but need more testing), during Prime 95 stress test or OCCT the processor fails to maintain 4.5 GHz. It sometimes settles at 4.3 GHz, other times at 4.0 GHz... The temperatures remain normal, below 65°C under high load.

Tests indicate no errors, so it seems stable, but I’m curious why the CPU doesn’t reach 4.5 GHz in professional stress tests, while it does in 3Dmark CPU stress test. My motherboard is MSI Gaming Pro, has an 850W power supply, and 3200 MHz DDR4 RAM (underclocked to 2400 MHz if needed). I could try forcing the CPU clock to 4.5 GHz without enabling Intel EIST, but I’d rather keep the CPU idle when not in use.

Any suggestions?
I don’t run Prime95, but maybe at certain times the CPU isn’t fully utilized and EIST allows the frequency to drop. Trying Prime95 with EIST disabled might confirm if the frequency stays at 4.5 GHz. If it does, I’d assume everything is working correctly.

B
BoxmanCaIeb
Junior Member
7
05-29-2016, 06:49 AM
#4
Good thought, I'll give it a shot. It seems Prime 95 might require more memory than it needs for computation. All cores appear fully active regardless of the monitoring tool, but I'm unsure what exactly counts as activity.
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BoxmanCaIeb
05-29-2016, 06:49 AM #4

Good thought, I'll give it a shot. It seems Prime 95 might require more memory than it needs for computation. All cores appear fully active regardless of the monitoring tool, but I'm unsure what exactly counts as activity.

S
SFcoralsnake
Member
219
05-30-2016, 10:12 PM
#5
After attempting to disable EIST, the frequency remains at 4.5 GHz while idle, but switches to 4.3 or 4.0 GHz when using prime 95. I'm puzzled by this inconsistency!
S
SFcoralsnake
05-30-2016, 10:12 PM #5

After attempting to disable EIST, the frequency remains at 4.5 GHz while idle, but switches to 4.3 or 4.0 GHz when using prime 95. I'm puzzled by this inconsistency!

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BellaMaria88
Member
192
05-31-2016, 12:07 AM
#6
Benjamin Barrois tried turning off EIST, but when idle the frequency stays at 4.5 GHz; with prime 95 it drops to 4.3 or 4.0 GHz. I don't understand why. It might be throttling, but I can't see why. Have you checked Power settings? Are you against a power limit in BIOS? Someone else posted a similar issue recently—did they fix it? What are your Windows Power Options settings?
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BellaMaria88
05-31-2016, 12:07 AM #6

Benjamin Barrois tried turning off EIST, but when idle the frequency stays at 4.5 GHz; with prime 95 it drops to 4.3 or 4.0 GHz. I don't understand why. It might be throttling, but I can't see why. Have you checked Power settings? Are you against a power limit in BIOS? Someone else posted a similar issue recently—did they fix it? What are your Windows Power Options settings?