Overclocking Sandy Bridge-E, CPU Overclock Section:
Frequency of CPU is always Multiplier times Base Clock. Now with SBe we can further enhance the Base Clock (BLCK). It isn’t required to get superb overclocks; I personally tend not to use it. Unlike previous Intel platforms SBe’s BLCK straps are very virtual, and if you skip down to the BLCK strap section I will explain their affect in full. This section was done with a GIGABYTE UEFI BIOS, but the settings in this section are universal, so it can be used for other motherboards.Step #1: Determine what type of OC you want:
do you want a 24/7 OC? Or do you want something to pass a benchmark or just max CPU Clock? What type of memory frequency do you want? What type of cooling do you have? Once you determine those you should determine whether or not you want to use BLCK. You should also determine whether or not you want to use Power Saving states like (EIST, C1E, and C3/C6 states) to down clock your processor during less intensive loading scenarios like being idle. You should also determine if you want to just have a small OC without any voltage changes.Step #2 Increasing BLCK and/or Frequency:
You have to use Turbo Mode to OC SBe with every board. You need to leave Turbo Mode enabled, and set each multiplier, or just set one for all cores. On some boards EIST or C1E needs to be left enabled to use Turbo multipliers. On the UD7 it isn’t necessary to leave either one on. If you want to use BLCK straps or change BLCK, please do that first. Set the strap and BLCK you want and restart, if that doesn’t work go down to the BLCK Strap Section
for more help. Next after you find BLCK, whether stock or not, then start increasing the multiplier. Increase it two at a time. Please realize that you won’t be doing over 4.8 GHz 24/7, at least not many will because of heat restraints. If you fail to POST, or fail stability tests in Windows, then you need to increase your VCore. At this point you should disable power saving settings, which are EIST (Speed step), C1E, and C3/C6 states. On some boards you need to leave EIST or C1E on to maintain the OC at all.Step #3 Pick a good VCore:
Warning! At or above 1.7v the CPU will DIE. From 1.5-1.69v the CPU will DEGRADE more quickly than below 1.5v. When a CPU degrades it is very easy to tell, as it will require more voltage than before for the same frequency. Once you reach your max OC your VCore might be higher than you want. For every 100 MHz I use 30mv higher. So is my VID is 1.25v with a 3960X start with the maximum stock turbo ratio of 39x. Below is a list of Recommended Voltage ranges. The “Set to Get” column is a rough estimation of a voltage you can set and a multiplier you can set and get into Windows with. If that is stable, then you should move to reduce the voltage by 10mv-20mv steps until it is unstable and then increase it until you find the lowest voltage at which your processor is stable at for your task at hand.
Of course your processor could also be unstable at the voltages under “Set to Get”. If that is the case then you might want to get back into the BIOS, and look at some other settings.DVID Offset:
With SB and SBe we have SVID, and SVID will change the VCore unless the VCore is explicitly set. At 4 GHz my VID will be 1.30v, at 4.1 it will then be 1.315v, at 4.3 it will be 1.335v. Setting DVID is setting a positive or negative offset onto that VID. The issue is that VID changes with frequency, so if you set a +0.100v offset, at 4GHz it would be 1.4v, at 4.1 GHz it would be 1.415v, and at 4.3 GHz it would be 1.435v. You can’t control the final VID on these CPUs, so I do not recommend using DVID offset, but if you want the voltage to drop when the frequency drops then you need to use it. Please set the maximum frequency you wish to achieve, and disable all power saving features (EIST, C1E, C3/C6 states). Then boot into Windows and then restart and go into BIOS. Your max SVID bin for that frequency should now be your VID. Set the offset off this voltage, and then save, that will be your max VCore. If you increase the frequency more, then do that again, SVID might or might not change the VCore.
If you want the voltage and frequency to drop when the CPU is idle, you have to enable C1E and/or C3/C6 and EIST and you have to use DVID. Using DVID will allow the voltage to drop to 0.9v at idle when the CPU is only at 1200 MHz.Step #4 Test Stability:
For this step you need to monitor conditions, with a program such as CPU-Z
for frequency, and then something like HWMonitor
, or even motherboard software like EasyTune6-GIGABYTE
and TurboV/AI Suite II-ASUS
. Then you need a stress testing program, now there are two: Prime95
/LinX. So which is better? Well with Sandy Bridge is it apparent that Prime95 was the better one, even though in the past IntelBurnTest was just as good, it seems that something in the SB uArch is more heavily stressed with Prime95. SB also didn’t have huge issues with heat, one could reach maximum CPU clock without subzero cooling. SBe is not like this, there is no way you can reach your maximum clock on all cores without subzero. So my hunch was that IBT was better, since the heat was going to be more of a killer. So I did a power consumption comparison:
So IBT really does pull more power. But then I tried seeing which would fail first. Prime95 failed first every time, and it failed when IBT would pass. So same as Sandy Bridge, Prime95 is a better stability tester for Sandy Bridge-E than IBT/LinX
. Stability is subjective, some might call stability enough to run their game other like folders might need something that is just as stable as it was at stock, and then they would need to run Prime95 for at least 12 hours to a day or two to deem that stable. There are stability clubs and they require 12 hours or so of Prime95. There are benchers who really don’t care for stability like that and will just say if it can bench a benchmark it is stable enough. No one is wrong and no one is right. Stability is subjective. 24/7 Stability is not subjective.Step #5 Finer tuning Intel Power Settings and PLL OV:
Go under the Turbo Mode menu, you want to increase the processor watts to 500W and the processor amps to 300A. Those are the maximum that I could do in my GIGABYTE board, and they are way more than enough. Next you want to Enable CPU PLL Overvoltage, this setting really doesn’t do much at frequencies under 4.8ghz, but at and above 4.9ghz it helps. With some boards this setting has an odd affect; please look here for more info: http://hwbot.org/forum/showpost.php?p=138563&postcount=17Step #6 Finer Tuning LLC:
This step deals with fine-tuning LLC. LLC is Load Line Calibration, it helps reduce voltage droop under load. There was a scary article on Anandatech a while ago talking about overshoot, and explaining that VDroop is implemented so that overshoot doesn’t exceed VAbsolute. With modern boards and high-tech PWM technology, voltage output is more stable, and you shouldn’t be scared to use LLC with high quality board. MOSFETs are higher quality now on high-end boards, inductors are better, and so are VRD specs. Sure VDroop is still a good idea, but it isn’t as bad as it was in the LGA775 days. Do not be afraid, you can use LLC with great results. After all you are OCing, so your processor life will be hurt anyways.
Here is what LLC levels really look like (Remember: 80% or 0.8mOHM is standard Intel VDroop):
Go to your menu where you can mess with Load Line Calibration, or Vdroop Control. On many boards you have 3-5 settings, either names or values. On GIGABYTE LGA2011 boards it is a number, and the lower the number the stronger the LLC =less vdroop. On no board should you use the highest setting for everyday normal overclocks, the highest setting increases the voltage under load, and that can be harmful. If you are using a very low voltage, then that might help.
Here is an example, the LLC on my UD7. You will see how effective 30% and 45% are, as well as how 80% (stock) acts. I recommend the 30% or 45% or 3rd or 4th setting strongest setting on other boards.Measuring Vcore, the best way:
So currently 99% of users use software to measure VCore, but that is not a good way to do so. Software always under reports or over reports the VCore. This isn’t the program’s fault, but rather that software is almost always wrong when dealing with real voltage measurements. Just like no one should use software to measure their PSU’s voltage outputs, one shouldn’t use software to correctly measure VCore, especially when you are dealing with high voltages. Luckily there is a very easy method to measure VCore on all motherboards. Since VRM design is pretty much the same on all boards, with the output capacitors nearest the CPU socket being one of the last steps before the voltage is inputted into the CPU, we can measure VCore from the legs of these capacitors. It is best to use both legs, one for ground and the other for VCC (Power/VCore).Method #1:
Voltage read points. If you have a X79-UD7 or another board with read points, then you are in luck, as your motherboard has voltage read points, in convenient places so that you can hook your digital multimeter up to it.Method #2:
Measure VCore off of the legs of one of the output capacitors. These capacitors are closest to the CPU socket, and underneath the board have their legs. One of the legs can be used for VCC/power (red probe) and the other for Ground (black probe). If you are not sure which one is ground and which is power, then try it anyways, if the reading is negative voltage, and reverse the probes and it will be positive.Step #7 Fine Tuning VCore PWM Settings:
Next you need to work with CPU VCore settings from the PWM. If you want a detailed description of these settings, which correspond to a Digital PWM, like those on GIGABYTE boards please go down to the Digital PWM Settings Optimization section
. Since most board use Digital PWMs now, including GIGABYTE, you need to increase current capability, and possibly some other things. Go under the menu where you have the ability to change VCore switching frequency, phase control, ect. Increase the CPU Current capability to something like 128% for GIGABYTE boards, and more for other boards. Even board has a different current rating to the percentage of increase, for instances GIGABYTE’s 128% corresponds to 300A. Next if you have an option for VCore Thermal Protection, you want to increase that threshold as well. Then on some board’s you can/should increase the switching frequency as well, on the UD7 it makes no difference.
Now once you have optimized the VCore settings, please go back into windows, and test again.Step #8 Taking Care of CPU OC issues:
At some point you are going to hit a wall, no matter what you do you cannot get past it. That is how it is with SB and that is how it is with SBe. With SBe, going subzero will let you gain a few hundred MHz, which wasn’t the case with SB.
- If you are still stuck, and it is unstable and you are using BLCK Straps, try not using BLCK Straps. If you are using only Multi, then try BLCK Straps!
- If your BLCK is swaying 0.01-0.02MHz that is normal for SB and SBe.
- Keep VCore and VCCSA(IMC or System Agent voltage) as close together(.4-.3v) as possible for maximum stability, this is recommended by Intel.
- With SBe high memory speed will limit your CPU OC, so try lowering your memory speed if you have already OCed your memory. If you are having memory issues, please try to go down to the Memory OC section.
- You can also Increase VCore and/or CPU PLL Voltage for stability
- If you have a GIGABYTE board, and your OC is not sticking, please disable Easytune6, either uninstall it or make sure it doesn’t start on startup.
- You can always try a higher VCore, as that is really all you need for CPU frequency OC.
- If your OC is throttling, recheck your turbo power limits, recheck your PWM power limits, and then put a fan over the VRM area.
I used that Antec Khuler 920 and my results were generally decent. I was able to finally pull off 5.0 GHz after some fine tuning and BIOS release. My trick was the cool down my VRM heatsink with a fan. I had to open the window as it was getting hot, and stability was better in general.
My temps are shown below, it wasn't that cold outside.Max CPU OC Air/Water(5GHz):
1.608v is not required, in fact I can do it on 60mv less:
For 24/7 OC I found that 4.6ghz worked very well for this particular CPU in terms of heat and power consumption. You have to keep in mind that every single CPU is different and that clocks will vary. Just because someone can do 4.8ghz 24/7 and your CPU wont do 4.7ghz 24/7 doesn’t mean you suck at OCIng, it just means they have a better CPU or better cooling.
You can see I used 4.6ghz, and it 2400mhz memory. Well I will talk about tuning memory in the Memory Tuning Section. But next we have the BLCK Straps section to better explain them.