CPU Measured Speed

[Fitch]

Why does the measured speed of my CPU show 3.61 Ghz. when I had an overclock of 4.94 Ghz. when I ran PT ?



CPU Type Intel Core i7-3770K @ 3.50GHz
CPU Measured Speed 3.61 GHz
Motherboard SABERTOOTH Z77
Memory 16GB , Crucial Technology BLT4G3D1869DT1TX0.
Video Card Tested GeForce GTX 580
Hard Drive Tested INTEL SSDSC2CT120A3 (120 GB)

CPU Mark 12,975

[David (PassMark)]

Maybe the CPU didn't / couldn't get to 4.94Ghz?

For example it might be throttling down in response to being too hot when the measurement was taken.

[Fitch]

According to Core Temp and CPU-Z, it stayed at 4.94 and the temperture got to 85 C. Hot, yes, but not hot enough to cause throttling.

[David (PassMark)]

From Intel's specification for the i7 chips.

"To determine the highest performance frequency amongst active cores, the processor
takes the following into consideration:
• The number of cores operating in the C0 state
• The estimated current consumption
• The estimated power consumption
• The temperature
Any of these factors can affect the maximum frequency for a given workload. If the
power, current, or thermal limit is reached, the processor will automatically reduce the
frequency to stay with its TDP limit."

Unfortunately Intel don't publish the temperature at which throttling occurs. Instead they claim it varies from one cpu to the next (and maybe even between core in a single CPU).

There was a partial (old) list released here,
http://www.tomshardware.co.uk/intel-...ews-29460.html

As you can see from that list having a max temperature of between 80 and degrees 90C is typically what Intel set throttling values to.

The real test would be to improve your cooling and get the CPU under well under 70C, then try starting up PerformmanceTest. Note that launching PerformanceTest will load up your CPU pretty hard for a couple of seconds, so the temp needs to be fairly low before you start.

[Fitch]

OK and thanks. I do agree that I need a better cooling solution. Maybe water. I thought it seemed imposible to get nearly a 13000 Passmark rating for this CPU at only 3.6 Ghz.

[David (PassMark)]

We only measure the CPU clock speed once, when the program starts. So the CPU can throttle (or de-throttle) up and down during all of the tests.