This worked well for my garage PC that's a modded SFF HP with a 2nd power supply, hd-4870, 32" 720p lcdtv, i5-2500, win7 x64.
I found that forcing the i5-2500 to always run at it's max 3.4ghz Four Core Intel Turbo Boost speed does help. It also stops the latest "Plundervolt" exploit from slowing down your cpu and then making the antivirus, ect. work on the slowest cores and from causing BSOD's if it manages to drop the voltage enough. (That happened 3 times until i figured it out.)
https://www.techpowerup.com/262024/...s-vcore-to-fault-sgx-and-steal-protected-data
ThrottleStop is a small application designed to monitor for and correct the three main types of CPU throttling that are being used on many lapto
www.techpowerup.com
Make a shortcut to the startup file for it once you are happy with the way it runs.
Drag and drop the shortcut into Start\All Programs\Startup. It should run on startup.
In CPU-Z there is a option on one tab so you can see the speed of all 4 cores.
This guide explains how to lower temperatures, increase battery life, and boost performance with ThrottleStop.
www.ultrabookreview.com
There is another program called Realtemp that also works.
In this vid he shows CPU-Z, ect. and how without it it throttles down to 798mhz.
View: https://www.youtube.com/watch?v=vW35quZWzBU
The i5-2400 should be able to run on all 4 cores at 3.2ghz. A extra 100mhz is better than nothing on a locked board\cpu.