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I want to overclock my i7-2600K - any advice?

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Jan 15, 2021
Hi guys
So while I am waiting for a better cooler on my i7-5820k, I thought I would see what I can coax out of my i7-2600K

This PC is one I use for retro gaming. It has two SSD (dual boot form BIOS) and has Windows 10 64 bit and Windows XP SP3

Here is the specification
ASUS Motherboard P8Z68-V
Intel i7-2600K @ 3.4GHz
16Gb RAM DDR3 1600MHz
GTX 750ti
60Gb Kingston SSD (Win 10)
120Gb Kingchuxing SSD (Win XP)
2TB Seagate HDD
600W Cooler Master Silent Pro Modular PSU
Arctic Freezer 13 Pro heatsink

Currently it is set to Optimal Defaults in the BIOS

This is the rig that the GTX 960 out of my X99 rig is going to end up in, once I get a new GPU for that one

Sooooo.... given that hardware how far is this one likely to overclock, and can someone give me a good BIOS configuration or other useful info on this mobo+cpu combo to start with?

What would be a good bench marking program to use?

My advice to start would be the overclocking guide we have for those chips. :)

(See the sandybridge/ivybridge OC guide linked in my sig)

Give it a try and report back/ask any questions! :thup:
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Cheers Earthdog , I like a good guide as a place to start and will read it and post back as I progress

Actually I wondered if this mobo was a good to start this project- so I had a look to see what was the fastest chipset to still support XP and it seems to be Z77, but a quick look on ebay says the good Z77 motherboards fetch far more money than you would expect for 10 year old hardware! This isn't even in the realm of rare/esoteric retro gaming hardware so that surprised me a lot!!

Anyway out of interest would a faster chipset even make much difference for what I am using this rig for?

And Is that cooler I have any good? Seeing as this was my biggest problem for the X99/i7-5820k overclock.... hmmm

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It might be good enough, only one way to find out (well yo could search for reviews). I would however confirm that the fan on the cooler is blowing towards the back of the case and that the fan mounted in the rear of the case is oriented to exhaust.
I decided to pull one of the DIMMs as I couldn't remember what was in this rig - I built it about 10 years ago, give or take, and never used it for games at the time, I was using it as a daily driver plus video editing. I think I did intend to overclok it at the time but never got round to it as it worked very well already. When built it originally had a Radeon HD 6850 in it, the GTX 750ti was a later addition last year when I started to use it for Win XP retrogaming.

The RAM is GSkill Ripjaws Z 2133MHz, four x 4Gb kit - I looked for some old reviews, and actually found one on this very site! It seems I bought some half decent RAM back in the day. So now I have the RAM timings, they are marked on the DIMMs.

Regards the case fans - there is the one in the back, behind the CPU cooler, blowing inwards. There is also another fan in the top of the case above the RAM blowing downwards (inwards). There is a third fan in the front of the case blowing outwards. The CPU cooler fan blows towards the front of the PC. The case is a Cooler Master Elite - I think it is the Elite 430, it looks exactly like this one https://www.coolermaster.com/catalog/legacy-products/cases/elite-430-black/

There is no fan in the clear side panel but I don't see any reason why I couldn't fit one. I could also fit another fan above the CPU heatsink if that i s advisable.

I remember now, the reason for this kinda 'back-to-front' airflow on the CPU cooler and rear case fan is because the heatsink won't fit on the CPU the other way round! -the CPU fan hits the DIMMS. Having said all that, the airflow in the case seems to work quite nicely as it is, but I am open to suggestions and advice.

I'll try playing with the BIOS settings tomorrow, as per Earthdog's guide, and see how well it overclocks.
Well technically as long as the back fan and cooler fan are facing the same direction, I suppose you're okay, but generally people use the opposite flow. Usually intake in the front, exhaust in the top / back.
Yeah I would normally follow that convention, but as I mentioned, the DIMMs are obstructing the Cooler Fan so it can not be mounted that way. The best idea I could come up with was fit the cooler the other way round and reverse the airflow. I never gave me a problem this last 10 years but then again I wasn't trying to overclock it, so we will see.
Ok, I followed the earthdog guide as best I could. I'm not sure that I found all the options I was supposed to change.

Once I made the changes and restart, the PC boots but bleeps a couple times and flashes up a message 'Warning! CPU over temperature' and then 'F1 to enter BIOS'. I tried a couple times but same thing happened so I set it back to optimal defaults and it is working as normal again

One thing I did notice that seemed a bit odd. On optimal defaults it sets BClk to 103 MHz and CPU multiplier to 43, but windows (My Computer - Properties) says it is running at 3.4MHz. I also noticed the optimal defaults set my RAM to 1866MHz and not 2133MHz (and I couldn't select 2133 it was not on the drop down list)

I manually set Bclk to 100MHz and then I could select 2133MHz for the ram.

Anyway, despite my best efforts it didn't work :shock:

See attached pics of how I set the overclock in the BIOS. What did I do wrong?
From what I'm seeing your RAM speed is set too high.
Sandy's from my experience don't like speeds much over 1866 so try 1600 with all else the same and see if it goes.

If so, tweak from there.
Oh dear!
I decided to take the rig to the workshop and check the Heat sink compound as it has been on there since I built this PC. I thought it may have dried out, and it had.

The main problem though, is the heatsink screws to the plastic base support around the CPU socket with two screws - and the plastic base has split where one of he screws fits. The screw fits but won't tighten properly. This probably happened when I transported the PC to Gran Canaria after escaping from the UK.

So the dried up heat sink compound was holding the cooler in place but once I fit some new compound, it doesn't hold in place properly on the side of the loose screw. I can tell this by pushing down on the loose side of the heatsink, the CPU temperature drops by about 8°C. So I had to improvise by taping a piece of plastic foam to the top of the heatsink and fitting the side panel such that the foam wedges between the panel and the heat sink. This keeps the temperature down, it's only a couple of degrees higher than if I put pressure on the heatsink myself, and the PC is running OK.

So no overclocking for me a the moment, instead I need recommendations for a new cooler. Funnily enough, when I googled, the Hyper 212 LED came up - and I thought I could use the one from my X99 rig when the new heatsink comes for that one. But unfortunately (and why I got the Hyper 12 LED for £20) it only has the LGA 2011 mounting kit.

Unless I can find someone with a spare LGA1155 mounting kit for the Hyper 212, I'm going to have to buy another cooler. :eek:

So, as I said, any recommendations for an overclocked i7-2600K? New or Used.
Contact arctic about replacement mount (probably unlikely at this age) and cooler master about additional mounting hardware. Hopefully someone can come through for you! Hopefully such small parts will be less painful to ship. Could also check ebay for 212 mounting hardware, as those things are so common.

The ones mentioned in the other thread would be fine as would the hyper 212. I would focus on ensuring that a replacement cooler will clear your ram and still fit in the case
Thanks Zerileous
Yeah if I can find a mounting kit that is the other way to go and I could re-purpose the 212 from the X99 when the Noctua U14S arrives

I found this mounting bracket for the Hyper 212 LED but I am not familiar enough with these coolers to know if this includes everything I would need. It says this is only the backplate

I have read that Sandy Bridge CPU's don't generally go above 1866 memory speed, and I was never able to get mine going that fast but that may have been because I was running 4 sticks.
I was able to boot the MB with the CPU set to 4.0ghz and blck to 105. Set the CPU to 1.35v-1.4v (<- SB can take this for a basic posting test), CPU PLL to 1.9v, and make sure CPU PLL ov is enabled. With this setup - I was able to do 5.4ghz (1.625v -> on 2 cores for superpi & cpu frequency) w/104 blck and ddr3-2133 OCed to 2200+. I used a evga 360mm aio for the testing before I bench it under cold.
^ There are many guides for overclocking the i7-2600k. We also have quite a list of info under i7 2600k -> under our search section :thup: If you are looking for the “MAX” speed capable, then HWBot.org is your place :) I’m using a high-end aio to reach 5.4ghz and will need my single stage cooler (-35c) to go higher. This is with ONLY (2) TWO cores enabled for single stage 2D benching. This speed may be lower and/or require more power when running with 4c/8t enabled.
You should be able to reach 4.2-4.4 with a good air cooler and 4.5-4.7 with a high-end air cooler.
If you have questions about benching or wish to join our benching team, just ask :)
I'm wondering how much you can overclock it? And how?
^ You need to be more specific on your cpu, motherboard, and memory

- From what I have read on overclocking -> Start with a basic speed (like 40) and a easy/light voltage (like 1.3v) setting in the motherboard’s BIOS. You will leave the memory at auto or xmp until you have found the max speed of the cpu. -> This is HIGHLY dependent on your type of cooling!! The colder you keep the cpu = the faster you can run it. We have different sections for the different types of cooling.
- We are here to help :cool:
I just broke my z68 mb = asus m4e-z :-( The i7-2600k was stuck @ 5.4ghz on aio so I put in under my SS. I got the same freq wall so I cranked the voltage to 1.775 to see if I could go faster :cool: I got a valid cpu-z @ 5.454 before the board errored and rebooted to 00. I thought it was the cpu so I ordered another 1 ($50) and then installed my i5-2500k to bench. The board still reads 00 even with a different cpu :-( I’ll have to grab another one before I can finish my benching of the lga-1155.