Ivy Bridge Basics
So to begin this guide a primer on overclocking the platform will be given as well as Intel’s recommended voltages and my recommended
voltages:
Ivy Bridge Voltages |
Proper
Voltage Name |
Other Names |
Intel Rec.
Max |
Rec. Range on
Air/H2O |
Max on
Air/H2O |
Max on DICE |
Max on LN2 |
Description |
VCC |
Vcore |
1.52 V |
1.3 - 1.45 V |
1.55 V |
1.75 V |
1.9 V |
Vcore is the voltage provided to
the CPU Cores and is one of the only voltages that needs to be altered
to overclock on Ivy Bridge on |
VCCPLL |
CPU PLL |
1.89 V |
1.5 - 1.8 V |
1.89 V |
1.89 V |
2.0 V |
Can help reduce
temperatures and might also have cold bug impact |
VCCIO |
QPI/VTT |
1.08 V |
1.0 - 1.1 V |
1.20 V |
1.20 V |
1.4 V |
VCCIO can be raised to help with very high
memory overclocking |
VCCSA |
IMC, System Agent |
0.971 V |
0.925 - 1.1 V |
1.20 V |
1.20 V |
1.4 V |
Can
provide help with memory and or BCLK overclocking when under LN2 |
DDR Voltage |
DRAM Voltage |
1.50 V |
1.5 - 1.75 V |
1.82 V |
1.82 V |
>1.82 V |
DDR Voltage is very important for DRAM
overclocking |
VGFXVID |
iGFX |
1.52 V |
1.3 - 1.5 V |
1.52 V |
1.52 V |
1.52 V |
Voltage
for the internal graphics processor |
On Air/Water:
Intel Rec. Max is Intel’s absolute maximum rating for the Ivy Bridge lineup,
many of the numbers provided are identical to those of Sandy Bridge, however
while vcore should be lower because of a better processing technology (22nm vs
32nm) it is max 1.52v here because of the SVID max. When overclocking on air the
only two voltages you should need to touch on an Ivy Bridge setup are the Vcore
(which you increase) and the CPU PLL( which can be decreased to help
temperatures). You should not proceed to just apply the maximum voltage for the
vcore, vtt, or system agent as you will heavily increase the temperature so much
so that the CPU will throttle and can be damaged. Also if you start off with a
higher temperature it is very hard to test stability, as you will probably be
more unstable than if you used a lower VCore.
For 5GHz for instance, it is possible to OC to
5GHz with 1.4v on air:
However the wPrime score isn’t very good as the CPU’s heat is causing
it to throttle a little bit.
5.3GHz is my maximum validation on air:
Under LN2/DICE:
Temperature is more important for high clocks than voltage is when it comes to
Ivy Bridge. Also under LN2 higher vcore might not yield a higher clock, as it
will add more heat which can have an opposite effect. So while at 1.84v I might
do 6.6 GHz if I increase to 1.86 I can only do 6.55, but if I lower the vcore to
1.83v I can still only do 6.55, it is all about working the volts very carefully.
I should take a second and note that Ivy Bridge is an extremely tough CPU, it is
very hard to kill, however you can kill it if you go above 1.6v on air and ~2.0v
on LN2. Ivy Bridge also seems to be more resilient to degradation than Sandy
Bridge was, however the heat produced by the CPU can cause degradations when
above what Intel recommends.
TJ Max for Ivy Bridge is 105C, however you shouldn’t go above 85-90C load when overclocking.
Ivy Bridge also shows a lot of power increase due to frequency alone as well.
You can see this in the graph below which represents a 3770K with a fixed
voltage of 1.4v. However at 5GHz it is still better off than Sandy Bridge-E and
right around where Sandy Bridge is at for 5 GHz. What is increasing to increase
the power is the current, you cannot control the current, but you can control
the frequency and voltage.
Power Scaling with Change in Frequency Alone
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