Most people here at EK have Intel Core 2 Processors, This article is for those who have the proper hardware, dedication, and the will to push their systems to the limit and is meant as a reference for overclocking which contains detailed descriptions of technical names that you might encounter, overclocking is a fun thing to do but as always there are a lot of risks involved with it and you might end up with your expensive and hard earned hardware damaged beyond repair, so first ill start this article with the Risks involved
Things that can go wrong when you overclock your System
Terminology
In this section ill describe some technical words you will encounter throughout your OC adventures, in detail.
[/FONT]
The best way to detect your Processors Tjunction max temperature is to use the Software tool CoreTemp, it automatically detect the Tjunction of any Core 2 CPU, the trick is not letting the Cores get close to this maximum temperature by a delta of at least 15C
Tools you will need
© Zeraphine/2008-04-04
Things that can go wrong when you overclock your System
- Overclocking the CPU means pushing your whole system to its limits, not only the CPU, because CPU clock is interconnected to every data path of the system, when you increase the front side bus, all the other busses connected to it will increase in frequency simultaneously, this includes the PCI bus, PCI Express bus, AGP bus, Memory Bus, the lot.
- ·Your CPU can over heat and fail if you OC it without proper cooling and with High Voltages
- ·You will void any warranty for the CPU if you overclock it
- ·CPU’s life might reduce
- ·System RAM might over heat and fail if the RAM can’t handle increased clock speeds and Reduced timings
- ·Your expensive VGA card might take damage if the PCE clock remain high for extended periods of time
- ·All other Peripheral cards might fail if they can’t handle the increased clocks
Terminology
In this section ill describe some technical words you will encounter throughout your OC adventures, in detail.
- Front Side Bus (FSB) – Front Side Bus is the name of the data transfer bus that carries information between the CPU and the Northbridge, it is the main interconnect that link the CPU to the rest of the system, this bus plays the major role of deciding the CPU frequency as it is a Multiple of the FSB frequency (explained later)
- Northbridge (NB) or Memory Controller Hub (MCH) - The northbridge typically handles communications between the CPU, RAM, AGP or PCI Express, and the southbridge. The north bridge playes a Major role on how far you can push the FSB frequency and the RAM Frequency, Older the MCH on your motherboard harder it gets to overclock you system, an important thing to remember about modern FSB frequency is they are usually Double pumped or Quad pumped this means they actually transfer twice or four times the amount of data per clock, for an Example a FSB of 1066 MHz is actually working at the base frequency of 266 MHz and is Quad Pumped, means its processing Four times the data per clock, you should always use this base frequency to calculate the CPU frequency . Below are some FSB frequencies for Core 2 systems and corresponding base frequencies.
- 800 MHz effective/ Base Frequency is 200 MHz/ Quad Pumped
- 1066 MHz Effective/ Base Frequency is 266 MHz/ Quad Pumped
- 1333 MHz Effective/ Base Frequency is 333 MHz/ Quad Pumped
- 1600 MHz Effective/ Base Frequency is 400 MHz/ Quad Pumped
- CPU Multiplier - (or clock multiplier or bus/core ratio) is the ratio of CPU clock rate to front side bus or northbridge clock speed. A system with a CPU multiplier of 10x will have its CPU execute 10 complete cycles for every cycle of its FSB. In simple theory higher you can set the CPU multiplier easier it gets to overclock a system, A multiplier unlocked processor is the Nirvana for Overclockers but they are extremely expensive, The CPU speed is calculated as FSB Base Frequency x CPU Multiplier = CPU Frequency
[/FONT]
- EIST (Enhanced Intel SpeedStep) this is a technology that used on Intel processors to save power during the CPU is idle, EIST automatically Reduce CPU multiplier when the CPU is idle or not under heavy load, When overclocking you should always disable this feature from the BIOS menu.
- C1E (Enhanced Halt State) this is a Throttling technology that reduce heat output of the CPU when it’s under load. Always Disable this when overclocking for maximum Stability
- TM2 (Thermal Monitor 2) This is in par with EIST and should always be Disabled from BIOS for Maximum performance and stability
- TCase – Tcase is the Estimated CPU temperature in the Middle of the Integrated Heat Spreader of a Core 2 Processor, the Maximum value for this Varies between different processor models and core Revisions, and it’s not measured using a thermal sensor, it is guessed by the motherboard so it is not reliable, always use the Tjunction temperature (see below) to properly monitor the heat output of your CPU
- Tjunction – Tjunction temperature is measured using two digital Thermal Diodes located on Each physical core of a Intel Core 2 processor, and is the most reliable method to measure the heat output of a Core 2, Maximum Tjunction Temperature varies between 85C and 100C between different Core2 models and Core revisions, AT NO TIME A CPU SHOULD EXCEED THIS LIMIT FOR EXTENDED AMOUNTS OF TIME. When a Core 2 reaches this critical temperature it shuts itself down using the integrated Thermal Switch to Reduce damage.
- Vcore – VCore is the Voltage that the CPU is operating, it varies between different models and core revisions. This is the most critical setting that corresponds to heat production of the CPU.
- VDIMM – Voltage of the DDR2 ram, Standard is 1.8 Volts
- Memory Timings – Memory timings can be useful to push the RAM little bit harder specially if they are value RAM here are the timings that we will touch on this guide,
- CL - CAS Latency Time: The time it takes between a command having been sent to the memory and when it begins to reply to it. It is the time it takes between the processor asking for some data from the memory and it returning it. Lower this value higher the memory speed will be, but it will hinder maximum frequency the RAM can reach, higher values allows the RAM to clock Higher but will result in reduced performance.
- TRCD - DRAM RAS# to CAS# Delay: The number of clock cycles performed between activating the Row Access Strobe and the Column Access Strobe. This parameter relates to the time it takes to access stored data. Again Lower this value higher the memory speed will be, but it will hinder maximum frequency the RAM can reach, higher values allows the RAM to clock Higher but will result in reduced performance.
- TRP - DRAM RAS# Precharge: The amount of time between the 'precharge' command and the 'active' command. The precharge command closes memory that was accessed and the active command signifies that a new read/write cycle can begin.
- TRAS - Active to Precharge delay: The total time that will elapse between an active state and precharge state. This is the sum of the previous timings: CL + TRCD + TRP
- FSB to DRAM Ratio – This is the FSB frequency relative to the DRAM frequency, it should be 1:1 to achieve maximum performance on Core2 processors, a 1:1 Ratio means if your Base FSB frequency is 400 MHz (1600 MHz Effective) also you DRAM Base clock should be 400MHz (800 MHz Effective), hence one of the main limiting factors of your overclock will be your RAM and how Fast it can operate, I recommend that you have at least 800MHz (PC 6400)RAM to overclock with maximum stability and performance
The best way to detect your Processors Tjunction max temperature is to use the Software tool CoreTemp, it automatically detect the Tjunction of any Core 2 CPU, the trick is not letting the Cores get close to this maximum temperature by a delta of at least 15C
Tools you will need
- CoreTemp – to monitor the Tjunction Temperature
- SpeedFan – monitoring the Fan speeds and various temperatures
- Orthos – for stress testing the CPU, for your system to be considered stable you should be able to run this program for at least 12 hours without generating any errors
- CPU-Z – Viewing information about the CPU clock, voltage, memory timings
© Zeraphine/2008-04-04
Last edited:
You get the award for the "stupidest post" challege 
