[Question] - What has my Core Speed & Memory offset by .05-1.5?


Mar 4, 2009
Hello HF Community,

I've successfully have OC my Asus Z87 board + Intel Core i5 4670K to 4.6 MHz (typically I leave it at 4.2). However, a burning question remains: why is it, no matter what OC setting I use (3.8-4.6 MHz), my CORE SPEED always reads off by 1.x and memory too.


4.6 MHZ OC / CORE SPEED (according to CPU-Z, SPECCY, etc) reads 4598.93 MHz / MEMORY reads @ 3799.1 MHz (it should be at 3800 MHz) / BUS SPEED reads @ 99.98 (should be at 100 MHz).

Regardless where I set my over-clock, it's always off by a "smidge" .....why? what could be the reason for this minor offset reported? I've tried GOOGLE, but I'm coming up with nothing: OC, I need your advice/experience on this one! Please assist!


Mar 30, 2007
BUS SPEED reads @ 99.98 (should be at 100 MHz).
That right there. There is always some component variation on motherboard (and even within processors) that will cause clocks, voltages, timings, etc to vary a little bit. I'm sure you have been sitting at a stop light before, watching the blinkers of the cars ahead of you. You may see two cars in what appears to be perfect sync, then over a period of a few cycles they gradually get out of sync. If you watched long enough they would get back in sync again. This is component variation. There may be a resistor in the blinker circuit of one car that is one or two or ten Ohms different than that in another causing the timing to be slightly different. Or a component in the alternator differeing in value causing the output to be 13.89V instead of 13.87V causing the blinker circuit to behave differently.

Same thing happens in virtually all electronic products. Nothing to be concerned about. On this board (P8Z77-V LE Plus) CPU-Z also reports the bus speed as 99.98, on my last board (P5K Deluxe) it reported 100.41. Only time to worry about bus speed is when manually setting significantly higher or lower than 100MHz. This can potentially affect timing on the PCIe bus causing problems with certain devices.