Overclocked to 5.1 Ghz (CPUZ confirmed) but only show up as 5.06 Ghz in Task Manager?

[thtran6]

Hello everyone,

I'm still new to overclocking but kinda have some practice and experiment with it over the last few weeks.
So I got my i7 8700k overclocked to 5.1 ghz at about 1.368 vcore on a MSI z370 A-Pro motherboard. The temp at idle is solid 36C across all cores. I have not run any stress/stability test with this clock yet, but I have played several games that put the cpu to about 40% load and the temp was on average around 55C-59C, rarely spiking up to 62. Is this acceptable?

My second concern is: I used CPUZ to confirm my cpu frequency, which shows up to be strictly 5,100 Mhz across all cores. Sometimes there is a + or - 1 to 2 Mhz but that's about it.
However, when I opened Task Manager and looked at the CPU Performance tab, the frequency only shows 5.06 Ghz with absolutely no fluctuation. Does this mean I got bottle neck somewhere in my setup?

( I have also turned off speed step, adaptive voltage, c-state, and chosen High Performance power plan to make sure the clock stays at 5.1 Ghz the entire time. I got a gtx1080 and a 650w psu so I don't think power supply was a problem, as the frequency did show up clearly in CPUZ as 5100 Mhz)

Thanks ahead for all of your help!

 

[k1114]

That case is the nzxt h500, not the s340. Do not drill more holes. It's completely unnecessary and there's not enough space on the top to mount a rad unless you want to mount the rad outside of the case. The fan/rad setup is still the same. Front mounted 280mm, top and rear stock fans.

 

[thtran6]

That case is the nzxt h500, not the s340. Do not drill more holes. It's completely unnecessary and there's not enough space on the top to mount a rad unless you want to mount the rad outside of the case. The fan/rad setup is still the same. Front mounted 280mm, top and rear stock fans.

Thank you for the insight k1114!
I've been struggling to even find what this case is.
So yea, it looks like I'll be getting either the Kraken x62 or Corsair 115i with SP fans to mount at the front for intake, 1x140mm AF fan at top for exhaust, and 1x120mm AF fan at rear panel for exhaust.

All of those should sufficiently cool my chip I hope. I just tested at 5.2 Ghz with a lot of games and tabs opened and its only 40 C under 50% load, i'm surprised this 120mm is putting up this well. With the 280mm it'll be even cooler. Backing up to 4.4 Ghz at the moment.

Thank you so much guys.

 

[SgtScream]

Yeah it comes with everything included and as long as they are good quality fans you be alright. Look up the difference between static pressure and air flow fans.

Thanks for the insight there!
One last question. I am curious about how mounting the 280mm on the front of the case (or let's just say any intake case fan) would be able to in-take air? How does that work, because the whole front part of the case is sealed with metal skin and no vents, I don't see how ambient cool air could be sucked in.

Ah that's a good point. There's no ventilation anywhere?

The one in the link I sent earlier has absolutely no vents. I'm quite surprised they mounted a 280mm on there.

However, I just got home and looked at my case. I DO see vents on the left side of the front panel.
See here: https://imgur.com/GukKCBm
And on the top panel, there is vents on only half of it: https://imgur.com/EkpZDKZ

Suppose I could drill holes on the top panel to make more vents, which setup would be better to achieve lower temperature?

(1) put 240mm cooler on top panel for exhaust out (top panel couldn't fit 280), 1x120mm on back for exhaust out, and 2x120mm on front for intake

(2) put 280mm cooler on front panel for intake, 2x120mm on top panel for exhaust out, 1x120mm on back for exhaust out

You got it man. That'll work.

 

[k1114]

With whatever cooler you get, check reviews to see how good the fans are. You may be getting fans that aren't as good. Same with the case fans. From what I saw, the stock case fans are a good mix of airflow and sound. You probably don't need to buy any extra fans.