[gonz0]

Hey all,

Just wondering how i should go about OC'ing my processor. I read about how the intel multiplyer is locked so the only way to achieve high clock speeds is by increasing the bus speeds. I don't want to use the auto overclocker in the bios. I would rather adjust the settings myself since the auto feature adjusts my memory timings automatically. Which are usually slower than what it can acutally handle

I've read about this 1:1 Memory and CPU ratio. I don't really understand it. I've looked through my bios, and i've found no option that allows me to set that. Does this have something to do with keeping the fsb speeds of the both the same. I've already locked my pci/agp speeds @ 66/33, i read that it can mess up your system if you don't.

I've also read something about once you get a high clock you should try other ratios like 3:2 or 5:4. Whats that?

Basically, if you guys could give me some good info or links to good info on how to overclock manually that would be much appreciated. Maybe if someone has similiar system specs give me some of your bios setting and what you changed.

This is my first OC, other than my vid card. So be gentle .

[gonz0]

Ok, well I've started to OC it manually, I've pushed the cpu fsb to 210 and my 3.0c is now running @ 3.15ghz. Since i pushed the fsb to higher, did that also change my memory fsb too? Is there anything i need to look out for? Other setting i need to make sure i enable/disable? ect?

[gonz0]

Once i pushed it to 215, bios no longer loaded, had to flash back. Any help?

[jsx[ifl]]

I'm no expert, but try upgrading to the latest bios rev your board has, increase the fsp 1-2 mhz at a time and then run prime95 to stress test it. Check your CPU idle/load temps and make sure their under 60C, anything close to that is just too dangerous. Thats all i can think of

[CDsDontBurn]

w/your ddr400 mushkin memory, you're going to have to set the ratio at 5:4 when you're OCing your system (leave it at 1:1 ratio when you put your system at stock speeds). if you had better memory (like ddr 433, 466, or 500) you can keep it at a 1:1 ratio for anything above 200Mhz FSB.

remember to raise the voltage on your northwood, and do not exceed 1.7v on your chip. Many of the P4s can easily do 400Mhz overclock on stock voltages.

Keeping your pci/agp clocks at 33/66Mhz is definately recomended, because what you've heard is correct.

get the newest BIOS for your board. A newer BIOS will usually help out on stability, and/or get new features as well.

umm...that's what i can think of right now, just post back on what you've done so far and i'll be here to help, if i can't help on a particular question you have, i'm sure somebody else will

[Nacht]

since you're using ddr400...wouldnt it actually be slower if you put the cpu in anything greater than 200 on the frequency since that would throw it into asynchronous mode?

only other way to OC tho is with the multiplier....and to do that you need one of those newer asus boards.

[p0rChM0nK3y]

Some quick basics, as they pertain to Intel systems

1) Intel overclocking is achieved via the front side bus, or system bus. Depending on your system, it can be noted as FSB, CPU frequency, CPU speed, or something similar in the BIOS. Upping FSB will increase the system bus.

2) Intel CPU’s are “quad pumped” internally (Intel’s word for the process). What this means, I couldn’t tell you exactly…something along the lines of frequency multiplication. What this equates to for the end user is the front side bus will be ¼ the CPU’s advertised bus speed. If you have a 400 mhz FSB CPU, in BIOS it will be 100 mhz stock FSB speed. If you have a 533 mhz FSB CPU, in BIOS it will be 133 mhz stock FSB speed. Etc etc.

3) Conversely, DDR RAM transmits data on both sides of a tactical signal, effectively performing two functions per single clock cycle. That is why it’s referred to as Double Data Rate RAM. Some systems’ BIOS list actual DDR speed in BIOS (i.e. 333 mhz, 400 mhz, etc), while some list system bus speed (which is ½ of the RAM’s rated speed, i.e. 166 mhz, 200 mhz).

4) On Intel systems, best performance is achieved through highest possible stable operation in synchronous (1:1) CPU:RAM operation. The higher the FSB in 1:1, the better performance. The only exception may be if you have severely limiting RAM and a CPU that is an excellent overclocker. That is up to you to determine, tho. Does a 5:4 divider at a super high CPU clock offer better performance than half the FSB in 1:1? Well then, stick with 5:4. At the same time, running RAM faster than the CPU offers absolutely no performance gains (the CPU is doing the processing, RAM merely receives data as it is fed to it...). I don’t know why motherboard manufacturers even offer dividers to run RAM faster than the CPU, but they do. So, please, for my sake, don’t go setting your CPU bus speed to 133 mhz and DRAM frequency to 200 mhz (or 400 mhz, depending on how your BIOS lists it).

5) Intel multipliers are locked. FSB is the only way to overclock an Intel system. The locking of the multiplier is achieved via a laser cut on the CPU’s die. The channels for multipliers, other than the intended one, are essentially “blocked” from being accessible via BIOS due to this laser cut. The only exception to this rule is engineer’s sample processors. They are rare and not something you will ever purchase from your average retailer.

6) Proprietary systems do not overclock. Dell, HP, Gateway and Intel-manufactured boards all have their front side buses locked.

7) Familiarize yourself with the CMOS jumper. Once you start OC’ing, if you push a little too far and your system won’t boot at all, just clear CMOS and start over.

8) While this guide is intended to start you on your way to overclocking your current setup, keep in mind that upgrades will help achieve higher overclocks. Without saying right off the bat that you need to go out and purchase this or that, good cooling and a solid PSU are generally recommended for protecting your investment in a stressful operating environment.

Basic BIOS 101

Okay, now that we’ve established some basic ground rules, let’s get down to business. First and foremost, get into the BIOS. This is done by pressing the ‘DEL’ button at system startup. Once you are in the simplistic blue screen with all the wonderful (and possibly confusing, if this is your first time or you are still new to OC’ing), take a look around. Familiarize yourself. Read all the listings, and check out their available options. It may not all make sense to you, but it’s good to know where everything is. Something you can’t possibly imagine that you would ever need to change today may come in handy tomorrow.

Now then, let’s establish some basic settings that will apply to all BIOS’s and all overclocking. They may not appear exactly as listed, but it will be something very very similar:

Spread Spetrum – ‘disabled’
PCI/AGP/SATA – ‘fixed’ or ‘locked’ or ‘33/66/100’
Stop unused PCI clock – ‘enabled’

Furthermore, ensure that your “Initial Display Adapter” is set accordingly (i.e. PCI or AGP, depeding on your video card’s interface), and don’t hesitate to disable anything under “Integrated Peripherals” that you are not using (i.e. Serial Port, Parallel port, onboard audio, etc). This will free up unused resources.

Overclock

I will start with some general recommendations/knowledge, and finish up with the how-to.

Okay, so you’re in BIOS, you’ve made a few minor tweaks, as recommended. Now get to the menu that contains CPU freq., CPU voltage, Spread Spectrum, vagp voltage, etc etc. Your stock bus speed is already set. If it is greyed out, find the option to change from ‘auto’ to ‘manual’ that will give you access to such things as CPU freq., CPU voltage, etc. RAM speed may be listed in a different menu (normally Advanced Chipset
Features), so first things first, make sure it is set accordingly. If you have RAM that is rated to run on a faster bus than your CPU (i.e. a 533 mhz FSB CPU in conjunction with DDR400 RAM), awesome, you have headroom. You still want to set it to 1:1 operation, as this will offer the best performance. The exception, of course, is if your CPU is rated to run on a faster bus then your RAM. If this is the case, then set RAM speed accordingly.

Once you start overclocking, there will be three general limiting factors: vcore, RAM and heat. For Northwood chips keep your load temps under 55C and vcore no greater than 1.7v (whichever comes first, let that be your limiting factor). For Prescott chips, 65C load temps and 1.525v should be your upper limits.

Now that we have all that established, the general principles have been outlined and you have a general knowledge of the terms, what you will see in BIOS, and the basic troubleshooting principles for finding your system’s highest stable operating perameters, let’s get going with the actual procedure!!!! Start by upping CPU frequency (CPU speed, FSB) 3-5 mhz at a time. Again, this single setting will affect your entire system bus. Once increasing FSB, boot into your operating system. If you have reached the desktop successfully, then go back to BIOS and repeat until you experience instability (usually in the form of reboots or sytem lock-ups). Once you hit a wall, up vcore one notch. If this doesn’t help, up it another notch (see above paragrapch for vcore/heat limitations which should always be adhered to). If upping vcore doesn’t seem to be helping, then you can loosen your RAM’s timings (the higher the number, the looser the timing; so, 3-8-4-4 is the absolute loosest timings you can achieve on DDR RAM. If you see no gains, lower RAM speed (or CPU:RAM ratio/divider). Once you reach the point where you are not exceeding the RAM’s rated operating speeds (or are sure it will run at the current speed), and you are at the upper limit of either CPU temps or vcore, then you have found your CPU’s highest stable overclock. Congratulations! Once this has been achieved, and you are at the desktop at what appears to be a stable level of operation, I would strongly recommend testing stability with memtest (strictly for RAM), Prime95 (good all-around tester which offers torture tests for CPU alone, RAM alone, and overall system stressing), and 3dMark01 (good all around CPU/RAM/VC tester). Hopefully you have achieved an acceptable (in your mind) overclock. We expect some screen shots!

Granted there’s a lot of info here, and it may not all make sense immediately. Don’t hesitate to ask questions, start a thread, rely on the guys that have been at it for a while. We were all newbs once, and I personally have fried more than a couple pieces of hardware (some expected, some not expected). The bottom line, have fun, keep it within the parameters outlined, and if you see something that doesn’t look right (like greatly fluctuating FSB frequency), then shut your comp down, clear CMOS and try again.

taken from www.overclock.net

[CDsDontBurn]

Originally Posted by Nacht

since you're using ddr400...wouldnt it actually be slower if you put the cpu in anything greater than 200 on the frequency since that would throw it into asynchronous mode?

only other way to OC tho is with the multiplier....and to do that you need one of those newer asus boards.

yes, that is true, but you can also increase your memory timings. when overclocking occurs, memory timings decrease. by making the memory timings more agressively, you're overclocking your memory as well.

[gonz0]

Yea, i can't find any setting in the bios that changes the ratio. Anyone know where this is in the asus p4c800edlx bios? BTW, im running the newest bios available for my board. 1018.004

[gonz0]

I got the clock up to 3.75ghz with a 5:4 ratio. but it was highly unstable. Moved the clocks down to 3.6 and I'm going to stress test it over night with 2 instances of p95. Lets hope!!

[CDsDontBurn]

raise the voltage then. that should increase stability.

[gonz0]

What is the max safe voltage for p4northwoods?

[classic_leon]

Your CPU is good one. It can be overclocked to 3.2G. If you like, you can OC it to 3.4G. The max safe voltage for p4northwoods is 1.8V while you have a good cooler system.

[gonz0]

I have a ThermalTake Polo 735 HSF. Using the 1:1 Divider i was only able to take the OC to about 3.2Ghz, and that was unstable. Sometimes it would boot sometimes it wouldn't.

When using the 5:4 divider I was able to take the OC to 3.6ghz. But the FSB of the memory was left @ 180. Wouldn't doing that actually reduce my overall system performance. Since the CPU is running @ a higher bus, but the rest of the system is hindered?

Keep in mind that both of these overclocks were done without adjusting the CPU voltages, and I kept the Memory timings tight @ 2-2-3-4-6. (which are what the memory is rated for @ 200mhz.

Any suggestions on what I should do? Should I losen the memory timing and up the CPU voltages to take the 1:1 OC higher/more stable.

Or should i try upping the CPU voltages on using the 5:4 divider and try to take the FSB for the memory to 200mhz? To make it stable?

[CDsDontBurn]

Originally Posted by classic_leon

Your CPU is good one. It can be overclocked to 3.2G. If you like, you can OC it to 3.4G. The max safe voltage for p4northwoods is 1.8V while you have a good cooler system.

max voltage on a p4 C northwood is 1.7v

[classic_leon]

My friend tried to adjust voltage of on P4 3.2C, 1.8v can be set, and it shows as 1.79v on CPU-Z panel. But 1.8 is not recommended.

[CDsDontBurn]

that is way too high for a p4. if he keeps it at 1.8v, his p4 will be a like p2 in no time. then he'll be mad . voltages are usually rounded down about .01v~.02v so that's why it was mis calculated

[gonz0]

Originally Posted by gonz0

I have a ThermalTake Polo 735 HSF. Using the 1:1 Divider i was only able to take the OC to about 3.2Ghz, and that was unstable. Sometimes it would boot sometimes it wouldn't.

When using the 5:4 divider I was able to take the OC to 3.6ghz. But the FSB of the memory was left @ 180. Wouldn't doing that actually reduce my overall system performance. Since the CPU is running @ a higher bus, but the rest of the system is hindered?

Keep in mind that both of these overclocks were done without adjusting the CPU voltages, and I kept the Memory timings tight @ 2-2-3-4-6. (which are what the memory is rated for @ 200mhz.

Any suggestions on what I should do? Should I losen the memory timing and up the CPU voltages to take the 1:1 OC higher/more stable.

Or should i try upping the CPU voltages on using the 5:4 divider and try to take the FSB for the memory to 200mhz? To make it stable?

Any Input?

[classic_leon]

Pac-Man, you're right...
gonz0, it's a really dangerouse play. So, .

[CDsDontBurn]

if his p4 blows up or something, it ain't my fault, just letting him now not to keep them volts up so high.