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9900k idles at 4700mhz

Poons

Hi all,

 

I have recently upgrade my pc to a 9900k, Asus z390-I motherboard, 16gb G.Skill Trident 3200 DDR4 and a 2080ti. I enabled XMP1 in the bios to let the RAM run at its native 3200mhz but my 9900k seems to idle at 4700mhz on all cores with an occasional second dip to 800 after this change. When running Cinebench the clock speeds don't seem to change at all which is odd but the temps do spike up to 60ish. Is this normal ?

9900k4700mhzIdle.JPG

Under Load.JPG

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that's because you enabled MCE (multicore enhancement). Turn it off you want your C-states back.

CPU: i7-2600K 4751MHz 1.44V (software) --> 1.47V at the back of the socket Motherboard: Asrock Z77 Extreme4 (BCLK: 103.3MHz) CPU Cooler: Noctua NH-D15 RAM: Adata XPG 2x8GB DDR3 (XMP: 2133MHz 10-11-11-30 CR2, custom: 2203MHz 10-11-10-26 CR1 tRFC:230 tREFI:14000) GPU: Asus GTX 1070 Dual (Super Jetstream vbios, +70(2025-2088MHz)/+400(8.8Gbps)) SSD: Samsung 840 Pro 256GB (main boot drive), Transcend SSD370 128GB PSU: Seasonic X-660 80+ Gold Case: Antec P110 Silent, 5 intakes 1 exhaust Monitor: AOC G2460PF 1080p 144Hz (150Hz max w/ DP, 121Hz max w/ HDMI) TN panel Keyboard: Logitech G610 Orion (Cherry MX Blue) with SteelSeries Apex M260 keycaps Mouse: BenQ Zowie FK1

 

Model: HP Omen 17 17-an110ca CPU: i7-8750H (0.125V core & cache, 50mV SA undervolt) GPU: GTX 1060 6GB Mobile (+80/+450, 1650MHz~1750MHz 0.78V~0.85V) RAM: 8+8GB DDR4-2400 18-17-17-39 2T Storage: HP EX920 1TB PCIe x4 M.2 SSD + Crucial MX500 1TB 2.5" SATA SSD, 128GB Toshiba PCIe x2 M.2 SSD (KBG30ZMV128G) gone cooking externally, 1TB Seagate 7200RPM 2.5" HDD (ST1000LM049-2GH172) left outside Monitor: 1080p 126Hz IPS G-sync

 

Desktop benching:

Cinebench R15 Single thread:168 Multi-thread: 833 

SuperPi (v1.5 from Techpowerup, PI value output) 16K: 0.100s 1M: 8.255s 32M: 7m 45.93s

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welcome to the Linus Tech Tips forums!

 

more than likely, you'd changed the setting in the UEFI/BIOS to use MCE (Multi-Core Enhancement) option.

its usually an ask when you use the XMP setting in RAM.

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Ah that makes sense. I turned MCE off in the bios and set Windows to the balanced Power Management Profile. The cores now seem to fluctuate very quickly between 800mhz and 4700mhz which I guess is normal ? 

 

On a side note I tried out the Cinebench single core test just to see if it did indeed hit the magic 5ghz number. From what I can see in CPU-Z all the cores ramp up to 4700mhz and Realtemp implies that different cores are being picked for short bursts of the benchmark. Is this how it normally works ? I assumed it would use just 1 specific core for the whole test?

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Windows power mode made the difference. Max perf on and it wont drop clocks.

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I take it the CPU is perfectly safe to just sit at 4700mhz at all times ?

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41 minutes ago, Poons said:

I take it the CPU is perfectly safe to just sit at 4700mhz at all times ?

Yes, it is safe. 

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The way the turbo boost works on the 9900K is 5GHz on single thread, 4.7GHz on all threads, the temps and performance you're seeing is perfectly normal, and I see you already got the downclock problem resolved with MCE. 

 

Just got one of these myself about 2 weeks ago, loving it so far. 

Save up to 10% on eVGA.com purchases, use my Associates Code: 47AQQ6KPU2IZNXY

My system on ModRigs: https://www.modsrigs.com/detail.aspx?BuildID=42686 

Primary Rig:

CPU: AMD 5950X at 4.65GHz 1.275V - Mobo: Asus Crosshair VIII Hero - PSU: eVGA P2 1200W

CPU Cooler: EK Quantum Velocity Block (480mm XE Radiator with push/pull EK Vardar D-RGB fans)

2 x 16GB G.Skill Trident Z Royal 3600MHz CL14 RAM (14-15-15-35-1T at 1.45V)

GPU: eVGA RTX 3090 Kingpin Hybrid - Core @ 2160MHz @ 1068mV, VRAM +1000MHz

Case: Thermaltake View 91 - SSDs/HDDs: Too many to list; Samsung 980 Pro 1TB & 2TB M.2s, Samsung 4TB SATA SSD

Monitor: Samsung Odyssey G9 49" Super-Ultrawide 240Hz Monitor

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Ok so now I have more odd behaviours. With Prime95 running I get about 20-40 seconds of all cores working on 4700mhz then all of a sudden they all drop to 4300mhz and stay there. During the start of the test temps don't exceed 65 degrees so iy cant be a thermal throttling. Any ideas ?

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