Intel Overclocking!
Having recieved my new Intel Core 2 Quad Q6600 G0, i felt it was time to do an overclocking guide for you chumps.
The ways and means of overclocking and stressing differ depending on who you talk to. I will be using the same way i always have done. Feel free to add your own advice to the guide.
1. Why overclock?
Among the computer "pure", overclocking has a bad reputation. Apparently it's a potentially dangerous technique that leaves your computers health at the mercy of your stupidity. This is true, but it's simply one more reason to learn about how to OC thoroughly and safely.
If i have forgotten anything, remind me sharpish!
There are two main reasons for overclocking. The first is the most obvious, greater performance. In days gone, mainly the Pentium/Athlon era, the maximum overclocks were usually 200mhz or so. But, with the introduction of more advanced architectures such as that of the Core 2 Duo, this has been destroyed. Overclocking from 2.4ghz to 3.0ghz is now seen as a "safe" clock and relatively low! Getting 400mhz-600mhz out of a CPU will definitely sped up processor intensive tasks.
Secondly, for fun. Overclocking is a hobby. You try to reach that highest stable speed changing whatever voltages and frequencies to achieve it. It gets addictive!
2. Required Tools!
- Aftermarket CPU CoolerA decent aftermarket cooler is absolutely necessary for overclocking. It prevents overheating and potential damage to your CPU. Good coolers cost between £15 and £40 ($25-$70). Ask for advice when choosing.
- Arctic Silver 5 (or other specialist thermal paste)This is less important as coolers come with thermal paste. However, for best performance, buy a small syringe of Arctic Silver 5. It doesn't cost a lot.
- CPU-Z or Crystal CPUIDDownload either tool (I prefer Crystal as it shows the % overclock). We use this to measure the current speeds.
- OrthosWe'll use this tool to actually stress test. This ensures the overclock is stable
- CoretempWe use this to measure temperatures and ensure nothing is overheating
3. Preparing for overclocking!
It important to do a few things before overclocking. The first is to find out your CPU's specifications. Use "http://processorfinder.intel.com/" and find your exact processor (including the batch number). To find your batch number, check the side of the retail box or CPU heat shield. For example, here is the specifications for my Intel Core 2 Duo Q6600 SLACR stepping: http://processorfinder.intel.com/det...px?sSpec=SLACR.
It shows that safe voltages are between 0.85v and 1.5v and maximum temperature of 71c. Obviously, different CPU's differ, especially 45nm chips!
In the BIOS, we need to do a few things. First, disable Intel Speedstep Technology and C1E Advanced Halt state.
Lock the PCI Express Frequency to 100 and the PCI clock Sync Mode to 33.33mhz.
You then need to find the maximum voltage for your memory. This can either be found on the side of the actual memory stick or online on the manufacturers website. Set the memory to the maximum recommended voltage and reduce the speed as much as possible. Doing this means the memory won't be unstable while CPU overclocking. If it's unstable, it can lead to confusion.
Also, enter the north bridge config and relax the memory timings as much as possible. This means raising the numbers as high as possible. If you can't see the timing settings, you may need to disable an option called something similar to "Configure DRAM timing by SPD".
The times you need to relax are:
DRAM CAS# Latency
DRAM RAS# to CAS# Delay
DRAM RAS# Precharge
DRAM RAS# Activate to Precharge
For example, if timings are currently 4-4-4-12, raise then as high as possible, usually to around 6-6-6-18 or 5-5-5-15. Ignore the other timings.
Note: It is highly recommended you use PC-6400 (800mhz) memory or above. Slow memory reduces the amount by which you can raise the front side bus.
Finally, ensure the CPU multiplier is correct. This will be found in the CPU settings. To find the correct multiplier, return to the "Intel processor finder" recommended earlier.
Note: Leave all CPU, NB, SB voltages on auto! We will deal with them later!
4. Overclocking!
Now we begin overclocking. Firstly, we want to check the CPU is stable at stock frequencies. This is merely to ensure the CPU is not defective. This only needs to be done for 30 minutes.
Open CPU-Z or Crystal CPUID to make sure all the speeds are correct. Then open Coretemp and leave it on the temp monitoring tab. Open two instances of Orthos for quad core CPU's and one instance for dual core CPU's.
Dual core owners can skip this bit and move onto section 4.1. If you're using a quad core, you should have two instances of Orthos running. Hit "ctrl + alt + delete" and go to processes. Find both "orthos.exe" processes. Right click on one of the "orthos.exe" processes and then click "set affinity..."
Unselect CPU2 & CPU3, leaving CPU0 and CPU1 ticked. Press OK. Repeat the process with the other orthos.exe except unselect CPU0 & CPU1 leaving CPU2 & CPU3 selected. This way, we are stressing every core of the CPU!
Every time you reboot and open Orthos again, you must set the affinity again.
4.1: Raising the speeds!
Dual core owners will only see one version of Orthos, Quad core owners shall see two. I have a Q6600 hence why i run two copies of Orthos. Close all background tasks and ensure screensaver and monitor standby is turned off.
One thing to note is that as you raise the front side bus speed, the memory frequency will increase. If you have slow RAM, this may mean it becomes overclocked. This is why i suggested using PC-6400 800mhz or above. Always try and keep the memory speed as low as possible until finished overclocking.
Under the "test" dropdown box, select "Small FTTs - Stress CPU". Then, click "start", we are now stress testing. You should see the box at the top is green with the word "Go". Leave this running for 30 minutes and do not use the computer in the meantime.
If that passes, then we can raise the "front side bus". To work out what FSB is needed, you want to multiply the front side bus by the multiplier to receive the overall CPU speed.
E.g. 312 x 9 = 2808 (2.8ghz)
Raise the FSB by a number you feel comfortable with, however, i wouldn't go over 200mhz a time unless you're sure your CPU can handle it! You need to raise the speeds in the BIOS. When done, reboot your PC and repeat the instructions above (quad core users remember to change Orthos's affinities!)
Every test (bar the stock frequency one) should be done for an absolute minimum of 4 hours! Taking shortcuts here can lead to an unstable overclocks, crashing and a bad headache!
So, keep raising, stressing, raising and stressing.
Note: Make sure temps do not go over 65c when under 100% load!
4.2: Failed overclocks!
At some point, you'll get to a point where the CPU isn't getting enough power (voltage) to run it at the correct speed. When this happens, orthos will fail the stress test. Where there used to be a nice, green "Go", there will be a big, red "stopped" or a big blue screen!
At this point, you do two things. Firstly, enter the BIOS and raise the Northbridge voltage to either 1.45v or 1.55v provided you have active cooling pushing air over the northbridge heatsink. Then, try running the stress test again.
Should it fail again, you need to raise the CPU voltage or VCORE in the BIOS. Before you do this, you need to find out what the safe voltages are by asking other users with the same CPU and checking the Intel CPU finder. Remember, the higher the Vcore, the hotter the CPU will run, so don't put it to the maximum straight away. Increase in small increments.
Raise the voltage and start testing with Orthos again. Eventually you'll either reach the heat limit where the CPU runs too hot and you can no longer raise the VCORE without overheating. If this isn't the case, you've probably reached the natural chip limit. At this point, you want to do a final, long stress test. Stress for 8 hours and if it's stable, congratulations, your overclocking venture is over!
If it's not stable, you need to start reducing the FSB frequency and thus the overall CPU speed. Do this whilst leaving the voltage until you find the point where the CPU is stable. Do another 8 hour stress test and hopefully, Orthos stays Green! If again, it fails, it may be that your RAM is simply too slow and overclocking the FSB has overclocked the RAM too far. At this point, you simply need faster memory.
So, your CPU is now overclocked and stable! Congratulations. You can leave it here, or if you are enthusiastic, you can try dropping the multiplier and increasing the front side bus. Whilst the CPU won't run any faster, it will marginally increase the overall system speed since it is a main data bus.
Comment