[gcwebbyuk]

I currently overclock my 2600k to 4.5GHz, with a max temp of 75c (65c during gaming etc).

I would like to push things a little higher, as I know the chip has it in it.

What temp should I use as a max temp? I think the tjMax is 98c, but what is a safe temp to max out at when running stress test.

[SMOKEU]

I personally don't feel comfortable running mine any higher than mid 70s. I have heard that stability issues CAN occur when temps get into the late 70s.

What CPU vcore are you running to get that speed? Those temps seem a little high for 4.5GHz.

[bennoculus]

I usually say 70C is the max for a daily overclock. 98C is where it will start throttling like crazy.

What kind of voltage are you using to get to 4.5GHz?

75 seems a bit high for that low of an overclock... What is your ambient room temperature?

[EarthDog]

Keep it at 80 or less for stress testing.

[SteveLord]

I am going to try and get up to 4.5ghz myself. My cores now are in the low 40s idle. Good to know what some of the recommended ceilings are.

[gcwebbyuk]

The board I am using is a Sabertooth P67. I have the CPU V on the Auto setting - when stress testing, it shows up as 1.36v.

[SMOKEU]

Originally Posted by gcwebbyuk

The board I am using is a Sabertooth P67. I have the CPU V on the Auto setting - when stress testing, it shows up as 1.36v.

Not a good idea - the BIOS will normally give the CPU too much vcore when left on auto whilst overclocking. This is to allow for manufacturing variables in the CPU.

Set your vcore manually, and go for the lowest voltage you can get away with while still being stable under heavy load (Prime95 running 8 threads).

Do not exceed 1.45V as voltage degradation may occur.

[gcwebbyuk]

But surely it needs roughly that voltage anyway?

I agree when locking down the overclock it is worth making settings manually - but even then I would probably be using 1.35 ish?

[Bisquit]

It depends a bit on the type and brand of the motherboard, but on my system the auto voltage gives around 1.320v for 4.5Ghz. Runing prime95 it will drop to 1.288 as a minimum and hoover between that and just around 1.300v
A slight load however puts 1.325 on the cpu, according to cpu_z.
I need slightly less vcore for 4.5Ghz, it takes off roughly 1 or 2 degrees celcius.
On some sytems the vcore is set much higher than needed, making the difference in temps bigger.
Not a problem with excellent cooling, the cpu probably notices nothing with the little increase in voltage. On medium coolers however the impact is somewhat higher.

It's with the higher multipliers the auto setting will set a much higher voltage for cpu.

Below 80 for stresstesting is the general consensus.

[SMOKEU]

I need 1.435V with LLC set to "ultra high" to get it stable at 4.7GHz, which seems to be a higher voltage that what most other 2600K processors need, going by what most other people say in other threads.

[Bisquit]

Could be, yes. Although it varies for many users. It can change with adding 100Mhz to the cpu. Also some report the voltage setting in bios, which could be 0.05 higher opposed to running windows and cpu-z or other monitor programs because of vdroop.
Others report what cpu-z is telling them.
I found on my asus board the bios isn't flawless, loading a profile for instance, could result in instability while that profile settings was rock solid before. Loading and saving it again in bios usually fixes this for me.
Using auto at one time gave lower vcore than before, reloaded the setting and saved it, after that the auto setting gave the correct, somewhat higher vcore.
Still, read some inconsistencies with the latest 1850 bios, so I will wait before trying a bios update.

[gcwebbyuk]

A little more info: I have recently swapped from a Gigabyte P67-UD4 (original release) to an Asus Sabertooth P67 (Rev 3). I was running a Coolermaster V10 (no comments please...) with Scythe S-Flex E fans instead of the Coolermasters. The Sabertooth has a PWM controller for the CPU fan, so I had to swap back to the stock fans for the time being - I have 2 Slipstream 1900 PWMs on the way.

I was used to cooler temps with the S-Flex fans, and swapping to the CMs has caused me to monitor the temps more.

I increased the multiplier to 47 on Saturday, and the temps went up to 85c - which worried me of course.

Hopefully the new Scythe fans will bring the temps back down to what I was used to.

[EarthDog]

Or just put it back to a more realistic overclock.. You are not going to be able to tell the difference in performance between 4.5 and 4.7. So why bother.

I run mine at stock and have custom water for it.

[gcwebbyuk]

Originally Posted by EarthDog

Or just put it back to a more realistic overclock.. You are not going to be able to tell the difference in performance between 4.5 and 4.7. So why bother.

I agree, and for day to day use I will leave it at 4.5GHz - I just wanted to see what the chip had in it

I managed an hour and a half of Prime @ 4.7GHz, but backed off when temps were up to 90c. Back to a safe 4.5 for the time being...