overcloclocking

[ian.p.h]

i have a 633 celeron and would like to overclock it and I'm not sure on how to go about it. from what I have read it is clear as mud, but I thought I could switch the jumpers so that the board would think that the FSB would be 100 mhz instead of 66, then reduce the the multiplier to 6.5 or 7. but like at said at the beginning I am not sure. any help would be greatly appreciated. :0)

 

[deuce]

Well, most things with computers there is only one way to have the "experience" at doing it and so get better which is actually do it and learn along the way. With overclocking it is a little different. If you have never done it before, just keep in mind that it isn't very hard but you have to be VERY careful, or else you might be asking Santa for a new cpu this christmas. Make sure you have MORE than ample cooling before you do it. Get a bigger cooler with a powerful fan. If you switch the fsb to 100 than setting the multipler to 7 will give you 700 mhz... lucky for you the celeron is supposed to be the perfect overclocking processor and you can safely run the bus at 100 Mhz. 92 is the next step down if your motherboard allows it but 100 will work fine. You should change the voltage to 1.75 or 1.8v. Don't over clock your 633 celeron past 950 as I have heard they don't like to run stable. At 100 Mhz bus you should be able to raise the multiplier to 9.5. If it seems unstable best stick with 9. If you are unsure of how to go about it then you might not want to do it but if you need more help (i.e. changing the multiplier, bus, ect) just ask and I will post it for you. Just be aware of what you are getting into.

 

[brianF]

the multiplier is locked internally on all Intel chips, don't even think about changing it, it won't work.

Your processor runs at a default 66.66 mhz bus speed with a 9.5 multiplier.

Your only option is to adjust front side bus speed. It is always best to do it in small increments rather than one big move, run it awhile and see if it's stable.

You will need decent cooling, if a retail processor than additional case fans, bay fans to move hot air out and pull cool air in.

Overclocking has risks, computers won't boot, hard drives get corrupt, etc. Be warned

You also have to factor in the agp and pci bus when overclocking as they are a ratio of the front side bus.

Normal speeds are 33 mhz for pci bus and 66 mhz for agp bus

With your current machine your pci bus is using a 1/2 divider to get the 33 mhz, you agp is using 1/1. If you take it to 100mhz front side bus the pci bus has to be changed to 1/3 and the agp bus has to be changed to 2/3 to be at the correct speed.

Overclock the pci bus to much and data corruption, load failures, etc. Overclock the agp bus too much and the video card will crash, lock up, or just plain fry.

Results from site listed below

Celeron II 633 Results....

Total Entries in Database for Celeron II 633 - 151
Average overclocked speed - 977 Mhz

Most of the above users where running special cooling, either oversized high power heatsink/fan combos or water cooling. Most had to up there vcore voltage to 1.9 or above. I wouldn't take vcore over .2 higher than default, it's just asking for a melt down. Also increaseing the voltage increases the heatload calling for more cooling.


http://www.overclockers.com/ in the cpu database

 

[ian.p.h]

thank yopu for your quick response. i have another question, you told me to increase my power supply to 1.75 or 1.8, but how do i do this? any advice you can give on this topic would be great.

 

[brianF]

It all depends on your motherboard, if it allows changing voltage settings in the bios and if you can change fsb settings.

I wouldn't bump the vcore up until I had too, if you change it and windows won't load that generally means you need to bump it up a little.

 

[deuce]

Oh... that's right. I forgot about the multiplier. Intel has it locked at one specified multiplier to prevent both overclocking and conterfieting. If your board supports all of these... then go step by step. These are all the common steps inbetween 66 and 100: 66, 75, 83, 92, 100. Like Brian said take it one by one and run it to see if it is stable. then move it up. Average o/c speed is 977 and so should definately run stable at 950 but don't push more than that. Using the 133 bus wouldn't be very smart.

If you have one of these boards: Abit BE6-II, BF6, BX133-RAID, Epox BX7+ (I know for sure these will do it... others will too) they offer 1 Mhz increase so you could do it that way once you get to 83... take it one mhz at a time... however that would take a while but if you have the time you might want to consider it, especially if you haven't o/ced before.

There is a jumper on your mobo that sets the voltage. Default for you is 1.65v. Post your mobo and I can check which jumper it is for you.


[EDIT: Opps I've been beaten. Ok second thought... in light of Brain's wisdom maybe you shouldn't up the voltage yet.]