Junior Member
Apr 13, 2017
Mobo: Asus P8Z77-V-PRO

Cpu: i7- 3770k

Gpu: Nvidia GTX 670 FTW

Trident X 16GB

Os: Windows 7 Pro 64

Cooling: Watercooled

Programs: Core temp, Cpu-z, Prime95

link used \video : www.overclocknet/t/1291703/ivy-bridge-overclocking-guid...

Hi, Im trying to overclock my Cpu, but i can barely get the ball moving because of an error i am unfamiliar with.

tried to get to 4.5hz

For a baseline :
My Bios settings are all set to auto, i run prime95 to test stability, everything works fine

following the video, it said to do a basic beginning test before changing the variables:
1.changing overclock to tuner to manual and leaving all to auto,
2. changing the ram timing to what is on the package which is 10-12-12-31-2N latency
3.memory frequency to what our ram can handle, that being 2400mhz for me.
4. dram voltage to 1.65

after completing those steps i run prime95 again, this time it doesnt run a complete test
i get the following error almost instantly:

FATAL ERROR: Rounding was 0.5, expected less than 0.4

what does that mean?

after that, i followed the entire video, changing settings and just trying to add more vcore to get it to work. i went from 1.25 to 1.50 nothing changed, except for the additional bluescreen every now and then.

what should i try to do next?

ive also ran memtest86 with 4 passes just to check if my ram was bad.

the problem seems to be correlated with just changing the mem frequency to 2400 instead of leaving at the auto of 1333

any solutions?


Senior member
Feb 14, 2009
Don't mix RAM OC with CPU OC. First adjust for one and then the other.
If you want to start with the RAM OC, deal with that first, get it stable and only afterwards work on the CPU clocks.