I agree, it's a very good start but needs more. Maybe you could integrate some of this into your guide?
Firstly, I think finding the CPU limit is the easiest thing to do. Trying to find the fsb limit is a lot trickier because there a more factors involved, like:-
RAM voltage,
RAM timings,
RAM fsb limit (some RAM just won't go higher, no matter what)
Motherboard northbridge voltage,
Northbridge heat (can cause all kinds of problems, especially onboard features like sound)
CPU voltage,
CPU speed limit,
CPU plain old fsb limit ( I mean even a 2ghz CPU can't run at 400fsb x 5 = 2ghz can it? no matter what you do to it)
To find the CPU limit is as simple as upping it's voltage until it won't go any further or you think your heatsink can't keep it cool enough. Also when you know the CPU limit it takes a factor out of guessing what's failing when hitting fsb problems later.
This is what I do and is how I know my system could run at 2.3ghz (230fsb x 10) RAM @ 11 - 4 - 4 - 2.5 without problems
Though for the sake of my ears (from the fans) and just to be 110% on the safe side I run at 2.2ghz (220fsb x 10) RAM @ 11-3-2-2 for normal use everyday use.
When playing a game I just whack it upto 2.3ghz and turn the speakers up.
1. Get your system 101% stable, with all your OS and programs installed, patched, updated, etc.
Create a backup! you aren't going to find any limits until things start failing, things fail, especially due to high fsb, can cause all kinds of problems with important files. BE WARNED!
2. Invest in the best cooling you can / or are willing to afford. This should consist of a minimum of:-
1x 80mm fan on CPU heatsink (preferably over 30cfm)
1x 80mm fan sucking air into your case
1x 80mm fan blowing air out of your case
I say 80mm fans because anything smaller and they'll need to be spinning real fast to move a decent amount of air about. Which means loads of noise, even 80mm fans are quite loud.
You could even 7v these fans, it will raise temps a little, but as long as you've got some air passing through your case it'll help.
A couple of quid on a couple of fans is a small price to pay for the gains you'll probably make. Remember heat is the enemy here, the cooler things are, the faster they'll go
3. Now start finding how fast your CPU will go. So up the multiplier by 0.5. I'll use same example.
Athlon XP1800+
Stock = 1533mHz
FSB = 133mhz
Multiplier = 11.5
3a Increase multiplier to 12. CPU now at 1596mhz
3b Make sure it's stable, if it is up it again to 12.5. CPU now at 1662mhz.
3c Repeat this process until either something crashes or it just won't post / start up.
3d Let's say it fails at 13.5 x 133 = 1795mhz. Up the
Vcore by 0.025
3e This time it boots @ 1795mhz. Repeat steps above until it fails.
3f Let's say it fails at 14.5 x 133 = 1928mhz, up the
Vcore again. Repeat until either:-
Upping Vcore doesn't help it boot, or
CPU temps are getting higher than you're comfortable with, or
You've hit the maximum Vcore on your motherboard.
3g Now let's say it hit 15 x 133 = 1995mhz by upping the Vcore a total of 0.75volts and it's stable. You try 15.5 x 133 it fails. Upping by another 0.025v doesn't help, another 0.25v still doesn't work but another 0.025v does and you're running at 2061mhz.
Now this is where personal preference comes in. You've just overclocked you're CPU from 1533mhz to 1995mhz by upping the Vcore 0.075v. A gain of 462mhz!! Is it worth trying to gain just 66mhz more by having to add another 0.75v?
I say no, and is the reason I run my system at 2.2ghz 24/7 instead of 2.3ghz. Others want the maximum and would disagree with me. (someone usually does
)
4 Now you know you're CPU limit is 2061mhz with 0.15v of extra volts or 1995mhz with just 0.075 volts extra. So it's time to find the FSB limit of your system.
With extra knowledge that your CPU limit is around 1729mhz (13 x 133) at default volts (because it failed at 13.5 x 133 earlier and you had to up the Vcore to get it higher.) You can set the multiplier to 10 knowing that if your system fails with the fsb at anything under 170mhz, it's almost certainly NOT the CPU and is probably the RAM or motherboard.
NOTE-If it fails at 170 x 10 =1700mhz, it could possibly be the CPU because although it did 133 x 13 = 1729mhz earlier, the extra 37mhz fsb could put more of a strain on it. Doubt it but it's possible, if you're unlucky you just might have a CPU that doesn't like high fsb's.
Once you do hit 170mhz FSB, drop the multiplier on the CPU to 9 or lower so you can keep it at default volts.( for now!)
Now follow the earlier guide for raising FSB. Except this time you can try these tips once you think you've hit the max.
Let's carry it on from where they left off and 179mhz is your maximum with RAM at 2.7v.
5 Multiplier of 9, RAM @ 2.7v, fsb @ 179mhz = 1611mhz
5a Go into BIOS and find the option where you can change your RAM's timings. I can't tell you where that here as every motherboard is different (some older ones won't even have this option) nforce2 chipset's do.
It'll have options like Optimum, Aggressive, Turbo, Manual. We want Manual.
When you select Manual, the numbers below it that were greyed out before will now be selectable!
There should be 4 altogether. The first one will be the biggest, probably around 9, the next two will be around 3 or 4 (may have the letter 't' after them) and the last one ( the most important ) can be either 2, 2.5 or 3 and is called CAS.
5b For an example we'll set these numbers to 11 - 4 - 4 - 3. Now it's a little murky messing with RAM timings as some RAM just doesn't like certain configurations in this department, but bear with it, it can be well worth the effort. I gained an extra 20mhz on the fsb just by changing these settings alone!
My RAM will not boot with the CAS at 3, even though it should make it easier than 2.5. It won't even boot at 3 with the fsb at 100mhz!! So if yours won't boot, try 11-4-4-2.5
This is called "slackening your RAM timings" by the way.
5c If you find some 'slack' timings your RAM likes and it boots at 179 x 9, it time to see if we can go higher. Try 180 for size first time.
5d Keep going in 1mhz - 2mhz increments.
5e Now lets say you've hit 189mhz x 9 = 1701mhz and it's booted, drop the multiplier on the CPU as you're getting close to it's limits again, or you can just up the Vcore by 0.025v to help.
5f Whatever you fail at now, could very well be your systems limit, but there's another trick up the experienced overclockers sleeve.
You should also try this if slackening the RAM timings doesn't help at all, as this could the problem and not your RAM. If this helps then go back to
5b and try again.
6 Up the voltage to your northbridge, ( can't think of the name for it right now I'll come back and edit it later ) it will be at 1.6v if on an nforce2 motherboard. So up it by 0.1v to 1.7v
Now when your system fails you now know your max FSB and max CPU clock. Let's say in this example 200fsb was the max.
You know it can't run at 200 x 10.5 = 2100mhz because your CPU won't do it. You could try 200 x 10 = 2ghz, it managed 1995mhz earlier. Maybe try an extra 0.025v so you've raised by a total of 0.1v Vcore.
If this is stable after running Prime95, 3D Mark2001SE congratulations!
An XP1800+ running at 2ghz on a 200fsb with 400mhz DDR is a seriously fast machine and a very good overclock from 1.53ghz on a 133fsb with 266mhz DDR.
I'd say about 40% faster, maybe more!
You can also try "tightening" your RAM timings slightly if it's rock solid stable. Maybe get it down from 11 - 4 - 4 - 3 to 11 - 3 - 3 - 2.5.
You could also try upping the RAM volts to 2.8v, it shouldn't be a problem as long as you've got good airflow through your case.
Now go and overclock your graphics card.
Maybe you could try integrating some of that into your guide NF7-S? It's a bit long winded I know, I can go on sometimes! Maybe with a bit of editing it'll help?
**EDIT There is also one more trick you can try to give your fsb a good boost, but I'm not sure how many motherboards have this option. The only one I know that has it for sure is the Abit NF7-S.
There's an option in the BIOS called "CPU interface". What this does is initiate the 1T command for fast performance. Disabling this option can in some cases allow for a huge jump in maximum stable fsb. Maybe as much as an extra 30mhz!
But...
it does make quite a big impact on overall system performance, so it's upto you to decide if the trade off is worth it. Maybe an extra 30mhz fsb is, but an extra 5mhz definately won't be.
As with every guide, there are no certainties. Every system is different so there's no point in posting your full system spec's and asking
" what will this overclock to? "
Every single system is different and there are way too many different configurations to list an exact guide for each one. Even 2 systems absolutely exactly the same in every single aspect will overclock differently.
Experiment and have fun.
)
