Cpu Clock / Multiplier:
This is what your CPU is currently set to. Generally its adjusted with the multiplier which increases your clock. A 8350 for example has a stock clock of 4.0ghz or 4000mhz or a x20 multiplier. The reason its x20 is its multiplying by the FSB which is generally 200. (so each step up by +x.5 increases 100mhz) for example 200 x 20 = 4000, 200 x 20.5 = 4100, 200 x 21 = 4200 etc etc. Each time this is increased you are increasing your processors performance, aswell as thermal output (HEAT)!Vcore:
This would be your CPU voltage. Usually changed by an offset or increased manually (see below for photos of offset). This will generally be increased along with the cpu clock / multiplier to keep higher clocks stable under heavy loads (this will increase heat substantially
every click up)LLC:
Also known as Load Line Calibration or Load Line Control. This can have many different effects from mobo to mobo, even motherboards of the SAME revision may have different effects. But what it does is increased the vcore during load to compensate for vdroop (in some cases causing vboost). A optimization of this setting is usually required to achieve stable overclock. Some see better results on all possible settings (off, auto, normal, high, very high and extreme/ultra high pending mobo).
Use care when testing LLC.
General rule for LLC: Lowest possible STABLE LLC with Lowest offset (vdroop OR vboost both ok) and Least amount of Jolty vcore.Last thing you need to know:
This is time consuming. Expect hours of tinkering to achieve true happiness
. Jumping up without stabilizing lower clocks first will just take more time and make headaches. Trust me: Take your time and get it right
Programs you will need:
(monitoring program kept well up-to-date Hwinfo32 for 32bit users)
How to use:
Generally just open with checkbox "sensors only" selected. This will run a program that monitors all your sensors. You will want to find your processor and keep and eye on it through-out. Always use processor temps NOT cpu socket temps. Always check for max safe processor temp online.IBT AVX
(Different then original IBT but looks identical, used to load cpu and test for instabilities quickly)
Get here(under additional software in main post):
How to use:
Open, set stress level to Very high (some use maximum but very high seems to load enough ram for me normal is not
enough) Then press start to begin instantly stressing your cpu/ram. Usually throughout overclocking i run atleast 3 tests each time before stopping and moving on. Eventually when you get to your max overclock you will want to let it run the full 10 or even 20 times (if you use prime95 afterwards then 10 is likely enough)Prime95
(used to test for instabilities over time)
How to use:
Open and select either small fft or blend. Most use small fft as it is hotter for cpu but I like blend better as it loads up the ram more and hits it with random tests that would be more realistic. Either will work fine but as soon as you press OK it starts. a bunch of boxes open and sometimes its a pain to scroll down to whats goin on in each one. But if it says worker stopped in any of the boxes, you have failed on one of your cores and need more vcore (or other possible instabilities).OCCT
(Mainly used for vcore graphing, semi-optional)
How to use:
Open and go to CPU:OCCT tab, View your vcore and what it is at idle, this should be close to what you set it in your bios (may vary). Then press GO to load up your cpu. Look at your vcore again and see what it goes down or up to. The difference between load and idle is your offset. OCCT will spit out jpeg graphs after stopped, very helpful. This can also be used as a stress tester and is great for testing PSU and Vcore/LLC, but I prefer IBT/Prime for actual stress testing.
In this guide I will be using a Vishera FX-8350 and a 990fxa-ud5(rev1.1 bios F11) as reference, Please keep in mind there are other possibilities to stability issues.
Make sure your ram is STABLE before starting testing. Many users have reported both good and no results from increasing CPU PLL voltage before overclocking. I personally have increased mine to "the last click up before the red" 2.695v
I usually start by making a .bat file to shutdown pc in case of emergencies. open notepad type this:
c:\windows\system32\shutdown -s -f -t 00
Save as something like killit.bat (.bat is important) into somewhere you can remember and wont randomly delete it.
go into hwinfo64 (sensors only) click configure sensors at the bottom.
MAKE SURE YOU DE-SELECT "Display Warning Window" OR YOU WILL NOT SHUT DOWN!
Click alerts tab, go down to FX-8350, click on cpu 0 (see photo) and press enable alerting if value is >= 70ish (whatever you feels safe for your pc). Now check-mark "run program" and select the "killit.bat" file you created earlier.
This will shut-down your pc if it exceeds the chosen temp.
This is mostly just in case your fans die (or pump if running water).
Disable Power Saving Features, Set everything stock
Time to go to verifying stability at stock and testing temperatures at stock speeds to compare to others with similar coolers (also to make sure its mounted properly and a stable cpu).
By everything stock I mean go into your bios and set almost everything to manual voltages (check your cpu manual or other posts I don't want to reference them all) but manual stock settings and do all the disabling of turbo-core technology and power saving features. Then verify stability.
(photo above actually from same bios on i believe a phenom processor which requires cpu unlock to be disabled and all cores to be enabled, my fx-8350 had a different setting that required AUTO or cores would be 10 degrees hotter, may need adjusting pending chip, recent reports also show reset issues with a few ud3 and ud7 users aswell recommend AUTO for FX processors to start)
(notice my cpu voltage is an offset of +0.125, this would be for an overclock of about 4.6-4.8ghz depending how good your chip is, but most everything is set to manual settings)
To verify stability quickly you can run IBT AVX on very high for atleast a few runs(3-4 minimum). you will want it to return a positive answer (sometimes it fails sometimes it just shows negative answers both are considered failure) generally +3 or more is best doesn't matter what the number is (some chips return different answers I believe just being positive may be all that matters although I'm always 3+ and the EXACT same answer every-time).
Keep an eye on your temps you really never want to exceed 62 on a FX-8xxx (check your processors safe oc range NOT just chip max
). If your not stable you may just need to move on to the next step (but if your still not stable after that you may have a bad cpu or may be some other issue, check addition info at the bottom for more stability tips).
Dont forget to compare your temps to others with a similar setup (probably need to run a full 10 run ibt avx to get a solid temp to compare with). You dont want to start overclocking if your 10 degrees above the normal (or more) even if your still in safe temps. You may have to re-seat your cooler or check for other possible problems prior to overclocking.
Once you have a base line you kinda know what your working with. Generally this is when you'd adjust LLC (if you didn't already have to do this to achieve stability at stock). Increasing LLC will increase your vcore during load (also sometimes during idle aswell).
With this you will want the least amount of v-droop or v-boost (Both ok) while being the least jolty or unstable. You want to start low and go up one level at a time. Try to be on the lowest LLC setting, with the least amount of offset vcore.
Some people need normal, some high (i use high) some even need very high or ultra/extreme. Some even end up on auto or off but this is less often (all depends on mobo, giga boards likely on high+).how to test:
Use OCCT to load up the cpu. watch the graphing to see how much your vcore changes idle vs load. offset= difference between idle and load.Remember:
Lowest possible LLC with the least offset and the least Jolty (extreme can be jolty vs high has same results with no jolts which is why i chose high)More LLC info:
You will notice that your heat increases aswell (for most) as you increase LLC. This is because your volts are higher during load. You can compensate for this by decreasing your vcore in bios (although you wont need to later).
Even though it makes you hotter this also makes it possible to increase clocks further. The reason you want the least amount of offset is during light loads like gaming where you are jumping in the middle of PC usesage (30%-80% pending game/cpu) you are also jumping in the offset of your vcore. So if you have a Large vdroop or vboost you will be jumping significantly up and down in vcore as your cpu load goes up and down.
The reason you want the lowest setting is this puts more stress on your VRM and Voltage regulators. In the long run I would assume
a high llc with steady voltage is still better on your cpu/mobo then a Low llc setting and jolty voltage but this has not been tested for longevity that I am aware of so just be weary and avoid extreme setting if possible.
Once you have your LLC set and ready to go and your stock settings stable. Its finally time to overclock. You then will go into your bios and set your cpu multiplier (cpu ratio or clock) up one notch(+x0.5) from stock (this will increase your clock 100mhz or to x20.5 or 4.1ghz for 8350).
Then boot back into windows run ibt avx on very high see results as well as delta (max) temps. If you get negative results or fail or freeze/bsod go back into bios and increase cpu vcore (you may also notice the "freeze test" in IBT this can be un-reliable but shows how well your cpu is handling the load, the flame should be consistent movement although generally not fluid).
If you do pass atleast
3 runs with a positive score, go back into bios and increase multiplier again.
Repeat until you get to the point where your getting too hot and/or are not able to get stable (i generally stay under 57ish after 10 full ibt runs as Prime95 is likely to get hotter
[some see up to 10 degree difference]). Then you may have to back off a click on cpu clock to stay cool enough.
For some chips there is what we call a "voltage wall" at certain clocks where you may feel like your never getting stable. The truth is you may just still need more vcore. Alot of air coolers will have trouble overclocking a beast like the 8350.
As you can see above I had ended up with 4.8ghz with my Noctua NH-D14(Non-pwm stock) and was hitting too high of temps (Around 65 fairly quickly). It required around 1.55v on my current setup which is the supposed "safe limit" for the 8350 (some have pushed MUCH further safely with proper cooling but most
air cooling wont go that far). I might have been able to get 4.7 stable enough but I decided with 4.6ghz as it was nice and cool way under temps:
After you hit max OC then make sure you've setup hwinfo64 as I mentioned above with the shutoff safety (may want to test your .bat file to verify it works). Then its time to run Prime95 overnight. Start by watching it for a couple minutes if it fails you may need more vcore. if you come back and any workers have failed overnight then you may need more vcore. if you come back and its still running 100% and no failed workers. You are pretty rock solid stable. Keep it running for like 24 hours your OVER stable
.Make sure to atleast check it for the first 30-40 minutes or so to keep temps under 62 (or your cpu's max safe oc temp).
It usually peaks out temps after 20-30min. If you end up maxing 65ish overnight no biggie as long as your stable you wont likely ever see that again during normal use (although keep an eye during folding or heavy converting if you do this often just in case, I have noticed convertxtodvd really pushes close to p95 temps).
If your PC turned off you hit your MAX temp set in hwinfo. If your at your logon screen then it likely BSOD or Crashed somehow (crash/bsod generally cause reset, not shutdown).
Once you have achieved the overnight P95 run (24 hours not needed, 7-12 more then enough) you are more then stable enough to handle heavy usage and should feel confident in your overclock. Overclocking can be safe if kept well within safe temps. Once you are done you can also re-enable AMD cool n quiet and any other power saving features you may want to use (most are fairly useless IMO but some use stand-by and such will need some enabled). After this you should feel safe folding / converting or doing whatever you need while overclocked and feel confident it will come out as it should (without errors), even overnight.
Congrats to those with new builds and those just learning, I hope this helped you OC like a pro During any overnight runs of any program (folding, gaming, converting, whatever) I still use hwinfo64 with the bat file just in case and I recommend you do the same you never know when a pump or fan could fail
FSB OCing is also possible but you will have to be careful as each increase also increases northbridge, HTlink and dram clocks aswell and you may need to decrease some multipliers to compensate.
Also Northbridge multiplier and FSB tend to have "dead spots" where they refuse to boot or sometimes refuse to get stable.
Me personally I ended up doing a FSB overclock and anything over 300 wouldn't boot, anything over 220 would NOT stabilize (of course with multipliers decreased to compensate). Finally I was able to get a small FSB boost overclock to stabilize (208) while only decreasing the htlink multiplier which I may not have needed to. Can be frustrating pending your boards FSB Overclocking ability:
Also required a boost in Dram voltage and northbridge voltage. Once you have multiplier OCing figured out FSB is not too difficult and lets you squeeze a little bit more out of the cpu + other components.
Here I will be slowly adding more info as I collect it on extra tips of stabilization as you get to higher clocks.
Firstly LLC may need adjusting as you get to higher clocks. It generally becomes more jolty the higher you go and sometimes requires higher llc or even lower (really depends on how your board / VRM respond to LLC and higher clocks).
Asus boards (possibly others with digi+):
Not sure if this applies to all asus boards but with atleast the CHV these can be helpful:
CPU Power Duty Control to Extreme
CPU Power Response Control to Fast
CPU Power thermal Control to 140
Also if your ram is higher then 1866 you may need help there:
CPU/NB Current Capability to 130%
Dram Current Capability to 130%
As mentioned above about CPU PLL this can also be named CPU VDDA on asus boards and usually is not as effective, but still worth upping a bit as it generally either helps or has no effect.
Many other motherboards will have more options for stability and overclocking. For instance some asus/asrock boards come with LLC on more then just the CPU. You will want to refer to your respected clubs and owners manual for your mobos for more information about specific bios attributes.
Hope this helped you understand overclocking
Feel free to reply with any questions
Feel free to reply with anything that helped you get stable aswell. I will add it to the additional info list so we can make this guide universal . Also any revisions or tips feel free to comment, thanks!
Good luck and STAY SAFE