Most recent version of this guide: https://pastebin.com/QL2zrrND
First of all, if you follow these steps & you end up with a dead cpu or mobo, I’m not responsible.
Quick&Dirty sky-lake, kaby-lake, coffee-lake / all round laptop cpu overclocking guide (overvolting & undervolting), sorry no amd experience here.
Overvolting applies here to intel i3-/i5-/i7-/i9- 6xxxK, 7xxxK, 8xxxK, but may be compatible with 4xxxK, 3xxxK, 2xxxK aswell, do keep in mind I’ll be talking about ddr4 instead of ddr3.
For laptop cpu’s, i would recommend undervolting using bios or XTU for better performance, since you’ll be limited by temperature.
undervolting will lower temps & therefore allow for higher turbo clocks under high load, since you will be thermal-throttling less or not at all.
If you have a xx-xxxxK CPU and a motherboard that supports overclocking, continue reading.
Tips for getting out of a boot-loop blue-screen-loop can be found at the bottom of the guide.
Intel uses adaptive voltage by default, meaning it will lower the voltage based upon clock speed.(so also lower temps & power consumption during idle VS. manual voltage.)
Something too keep in ming when going for those last 100MHz, since adaptive voltage will be less stable at higher frequency.
I will be ignoring memory speed/timings & ring/cache clock for now, since they will impact overall performance the least.
As for reaching maximum stable core speed as fast as possible:
you should have these applications installed & ready for use: realtemp, cpu-z and realbench or intelburntest.
Step #1 “Finding the right load-line-calibration (LLC) setting” (Important for high load stability.)
Set the cpu voltage in the bios to your maximum “safe” voltage, I do not recommend going higher than 1.35~1.4 volt for 24/7 use. (Please do some research on this)
Open cpu-z & look at the voltage, is it close to what you’ve entered in the bios? Yes, then continue. No, comment #1.
Now open realtemp for cpu temps, Try to keep it below 90C when overclocking, 80 would be better.
And open realbench, or intelburntest (will be faster, but is waaaaay hotter, perhaps the 512MB setting is better)
Anyways for this guide I’ll be using realbench Handbrake encoding benchmark.
Run a single handbrake encoding benchmark & monitor cpu voltage
Does the voltage stay the same or does the voltage slightly increase (let’s say by 0.030v or 30mv)? Yes, then continue. No, comment #2.
Step #2 “Finding the right core frequency”
I recommend using the sync-all-core-multiplier option over the per-core-multiplier (harder to determine being fully stable)
Start out with a multiplier of 45 on all cores for 45 x 100(baseclock) = 4.5GHz
About 95% of users should be able to get this stable with 6th,7th and 8th gen CPU’s @ 1.35v
Anyways to ensure stability run a realbench encoding run, let it loop 5~10 times. (or intel burn test 30 loops of 1024MB)
Did it finish the run without encoding error’s/crashes? Yes, continue. No, comment #3.
Congratz, you got your chip stable at 4.5GHz on all cores.
Want to get higher clocks? No, goto step #3. Yes, comment #4.
Step #3 “Finding the right ring/cache clock” (small gains, or big gains in memory intensive workloads. big=5%)
Same as step 2, but increasing voltage will help less or not at all & change ring/cache multiplier instead of core multiplier.
Also make a recovery point/backup or your system, I have corrupted my OS once this way, but I was not sure if it was memory or cache clock related.
Step #4 “Memory speed/timings” (small gains, or big gains in memory intensive workloads. big=10%)
Hopefully you bought 2 or more RAM modules and did not go the cheap way & bought 1 stick of 8GB, because performance will suffer quite a bit with single channel VS. Dual channel. (up to 50% in memory intensive full loads & up to 10% in “normal” full loads.)
If you have a higher rated memory kit, let’s say 3200CL15 ddr4, they have an XMP profile (eXtreeme Memory Profile), this is an overclock & you have to enable it in the bios in order to get the extra performance you paid for.
I you do not enable XMP the stick will default to 2133 with one of the many JEDEC memory timing profiles (CL15-15-15-36-T2 for example).
Example if you bought an single 8GB 3600CL16 ddr4 module your system would perform way worse that person 2 who bought 2 sticks of ddr 4 2133CL15, why you spend almost 1.5x as much.
But i digress.
For those who do not have higher speed kits, or want to push them to higher frequencies anyways, continue reading.
frequency & timings depend on the type of memory, samsung has for example B-die which are at the moment one of the best, really tight timings, while able to hit high frequencies.
But that is one of 3 factors(maby more), the motherboard may not be able to handle certain frequencies…(bios firmware updates can sometimes help with compatibility)
and the Internal Memory Controller (IMC), which can also limit performance.
I’m not even sure why I’m writing this.
Maximizing your memory bandwidth, can be done easily:
This works kind of the same way as core multiplier, scaling with voltage will stop at some point.
Note I´m talking about ddr4 not ddr3, ddr4 default voltage is 1.2v, XMP often use 1.35v or 1.4v even 1.5v(so yeah why would you not feel safe at this voltage, i mean corsair gives a lifetime warranty for their ddr4-4600MHzCL19@1.5v kit, which no your cpu can not handle).
(I believe ddr3 uses like 1.5v by default, all the way up to 1.8v)
Set vdimm/memory module voltage to 1.35/1.4v or whatever you feel is safe.(too high of a voltage can kill your IMC, )
Use auto timings in the bios, change your dimm/memory speed from 2133 (default) to let’s say 3000MHz, thats already more than what my 2133 kit can do.
save changes & reset.
(tips for getting out of a boot-loop are at the bottom of this guide)
upon getting to your maximum stable memory OC (yes you should also do a benchmark, realbench handbrake encoding again, this time way more reliable than IBT), you can start tuning the timings.
For timings, you should look up an in dept guide, all i can say about primary timings is, lower is better.
#1 I have no clue, could be LLC, or sketchy mobo, or incorrect cpu-z reading(did you get the latest version?), or maby you’re using an old mobo with a newer CPU(is the Bios firmware up to date?)
#2 If the voltage jumps way higher than expected, lower the LLC setting in the bios.
If the voltage drops below your “target” voltage, increase the LLC setting in the bios
#3 Either increase voltage, or lower core multiplier in the bios. (steps of 10mv, should be good.) then try again.
#4 Increase core multiplier in the bios & do the realbench loop 5~10 times. (or intel burn test 30 loops of 1024MB), again and again untill you get errors or crashes. want to go further? No, goto step #3 Yes, comment #3
If your cpu supports overclocking, so an ix-xxxxHQ chip, you can do the same as for desktops.
Meaning you want more performance for less power, or you want to extend battery life, or you want yout laptop to run cooler, etc….
ix-xxxxHQ chip owners should just use an offset voltage in the bios, let’s say start with offset -0.050volt or -50mv
save&reset, do a benchmark like explained in Step #2 of Desktop CPU’s.
all the other Intel chip owners should get an application called XTU (intel eXtreem tuning utility).
from there just lower the voltage in steps of 10mv or 0.010volt
then run a benchmark like explained in Step #2 of Desktop CPU’s.
Note that the XTU profile has to be re-enabled every time you restart the laptop.
By lowering voltage, you can essentially do more with less, allowing the chip to turbo for longer or hit a higher (maby even max) turbo clock.
power limits can also be regulated from within XTU, have fun playing, as long as you do not increase voltage, you cannot break your machine, whoohoo.
also for those people who want to have a cool laptop, i suggest turning off hyper-threading in i7&i3 laptops & disable the turbo with realtemp, or XTU. (uses 35% or less power under load and ofcourse with lower temps)
GETTING OUT OF A BOOT-LOOP/CRASH-LOOP(the system keeps resetting/default to settings which let it crash again):
Turn the PC of by holding the power button
Then unplug the power cable&flip the on/off switch(for laptops, unplug the cable & remove the battery)
Now hold down the power-button until all the capacitors are fully uncharged(usually 10 seconds or so), if you look in the case, all mobo lights will turn off, i believe even the light from the Ethernet-cable.
plug everything back in, start your machine & enter the bios, change the memory values back to default & save&reset (if they havn’t reset already)& try step 4 again, maby a bit less aggressive this time 🙂
For non-laptop users:
If that did not work, do it again, but before plugging the cables back in, look for the CMOS battery.
take it out, hold the power button down again for a few seconds, then put it back in.
now enter the bios, change the memory values back to default & save&reset (if they havn’t reset already)& try step 4 again, maby a bit less aggressive this time 🙂