Overclocking a Celeron 566

[SteveZombie]

I have a Celeron 566Mhz and an Abit BH6 motherboard. I've had this processor for awhile and never overclocked it out of lazyiness, but now that there are 1Ghz out and whatnot I think it is time to speed mine up a bit.

My motherboard only supports upto 533Mhz Celeron so I am currently running it as a 550Mhz PIII. Is there anything wrong with this? If I overclock it what should I go for? I was thinking 600Mhz or 650Mhz. I do have a good Heatskin/fan on it.

Another thing is, alot of times when I try to overclock(I fiddled with it a bit the day I bought it) something goes wrong and the monitor doesn't catch on. After turning the computer on and off continuously it does eventually turn on, but it's really annoying(I have one of those cases where you have to hold the button down for 6 seconds). Is there anything I can do to make it turn on immediatly?

Thanks for any help.

 

[spamboy]

First of all, if your motherboard says it's running it 550, it's wrong. You see, Intel chips have the mulitpliers locked, you can't change them. To get 550, you'd have have a FSB lower than 66, and I don't know of any slot 1 or later motherboards that can even do that.
However, all is not lost! My Abit BE6-II did the same thing. It's just a BIOS error. You shouldn't need to Flash it or anything, you just need to go into Softmenu and set the FSB and stuff yourself. See, the boards don't know how to handle the 8.5 mulitplier of the 566 unless you baby them and tell it what to do yourself. So go in and set everything to user define, then set the FSB to 66. That gets you your 566.
Now, to overclock. The reason it is crapping out on you is because of several reasons: A. You didn't change the voltage, apparently. If you up the voltage to 1.75, 1.8, or 1.85, 850 MHz is almost guaranteed. Why is 850 good? Because the FSB is 100, which is a standard setting. When you try to set it to one of those middle settings, you are overclocking your PCI and AGP, and they probably don't like it. If you can't make the jump to 100, or at least to like 95 (using the 1/3 PCI and 2/3 AGP dividers) then don't bother. B. Cooling? Don't try to do 850 on the standard heat sink, get a better one.

And when it won't boot up like that, there's nothing you can do to speed things up except flip the master power switch on your power supply, if you have one. I recommend switching it off immediatly at the first sign of trouble, so you don't screw something up.

 

[SteveZombie]

First off, when I first got the CPU I did try to "baby" it to get it to run at 566Mhz, and it still didn't work. When I had it underclocked to 550Mhz SiSoft Sandra, and Windows and other various programs would still tell me I had a 566Mhz Celeron (568Mhz, actually ). But how come I should go right to 100Mhz FSB x 8.5 mutliplier and not try 6, 6.5, 7, 7.5, or 8? Just a few minutes ago I went for the x6 and the BIOS told me it was 806EB Mhz, what is that supposed to mean? Shouldn't it have said 600Mhz? 100x6=600, right? I can't right now but later tonight I guess I will try 100x8.5. However, what should I set the core voltage at? I believe the default is 1.50. Am I supposed to gradually higher it until I find where it is most stable?

Any help is appreciated.

 

[zener]

your cel 566 has locked multiplier. No matter what multiplier setting u chose on the mobo, the cpu still run at x8.5. The only way to overclock it is to adjust the frequency bus. Thus 8.5 x 66, 75, 83..100, 103.... Hope that help.

 

[zener]

start with 1.8v and see how far the cel goes. Then drop the voltage to 1.75 v to see if it is still stable then drop it more untill you find the right voltage to make it goes fastest and stablest.

 

[SteveZombie]

That sure cleared things up, thanks

 

[spamboy]

Thanks, zener, I guess I didn't make it clear enough why you had to change the FSB. Thanks for covering me on that one.

 

[SteveZombie]

I just now tried to O/C to 850Mhz and I could only go upto 8x for a multiplier. I'm looking for a BIOS update now.

 

[SteveZombie]

I updated my BIOS and sure enough its working at 850Mhz. This is so sweet! I get 12FPS more in crusher.dm2 (went from 26 to 38) and I went from 1530 to 2302MIPS and from 759 to 1139MFLOPS. I'm kind of glad I didn't overclock from day 1 cause now it feels like I got a whole new computer!

Thanks for your help guys.

 

[SteveZombie]

OK I was wrong about it running at 850Mhz. After further testing I found it to be extremely unstable. I was playing a game of Quake 2 and it frooze. Then it started freezing when windows was trying to load. Then I downloaded and ran 3dmark2000 and I couldn't get that to complete a single test. Now I set my FSB to 75(1/2) for a total of 637Mhz and I managed to run 3dmark2000 with no problem, and got 36FPS in Quake 2(crusher). Now I'm greedy and am dieing to get the 850Mhz, is there anything I can do to make it more stable? The Core voltage was set to 1.7 which was the highest it would let me set it.

At overclockers.com there were serveral people with my same mobo and processor who managed to O/C their CPU's to 850 with the stock heatsink/fan. AFAIK my heatsink/fan is better than the stock heatsink/fan. Right after the crashes I touched the heatsink and it didn't feel hot at all. I dont want to try it with 83Mhz FSB because than my PCI Bus would be 41Mhz and I don't watn to take a chance in frieing a PCI Card (I have 4 PCI cards in there).

BTW my motherboard is a Abit BH6 Revision 1 (NOT 1.1)

Please help me hit 850Mhz!!!

 

[JmsAndrsn]

You must be using a slocket since you have a BH6. You should be able to change the voltage using your slocket as long as it supports adjustments. Most brand name slockets(IWILL, MSI, ABIT, ASUS, etc) allow adjustments but generic ones may not. You would probably be OK going up to 1.8 or 1.85V. Good luck and keep us posted.

 

[SteveZombie]

I have an Abit Slotket converter, but I thought my BIOS would need to support the higher core voltages? I will try upping it through the Slotket tommorow, its getting late.

Thanks again!

 

[JmsAndrsn]

The BIOS actually detects the default voltage of the CPU and allows you to make adjustments that are a certain increment above this default and some motherboards will allow you to set voltages that are below the default. It looks like your BH6 allows you to go 0.2V above the default voltage. By setting the default voltage on the slocket, you are are over-riding what the CPU's default voltage is. If you set the slocket to 1.7V, the BH6 BIOS will probably allow you to adjust the voltage up to 1.9V

 

[MustangSVT]

yeah increase the voltage and get a better heatsink and fan combo. u can set the voltage on that slocket. try that with setting voltage in bios.

my cel2 633 is runnin sweet at 950 with 1.75 v on no name slocket. It doesnt even have voltage setting on it so when i set it on bios (i have Bh6 too) it works fine.

Good luck.

 

[SteveZombie]

I set the voltage on the slotket to 1.7 but in the BIOS it was still set to CPU Default 1.50 and I still couldn't higher it any more than 1.70

Please help!!

 

[Dexion]

Lucky I had this BH6 and Celeron 566 combo!
Set your CPU Voltage to 1.7volts and flash your BIOS again! After the BIOS, you'll get up to 15% more ontop of the 1.7volts.

 

[SteveZombie]

I just flashed it with the newest BIOS update yesterday!
Did you have the BH6 Revision 1.0x or 1.1? To my understand there is a big difference. The 1.1 Supports the following: (take from Abit's website)

Supports the Celeron566(66),600(66),667(66),700(66)MHz CPUs, and PIII 750(100),800(100)MHz,850(100)MHz CPUs.

While the revision 1.0x supports:

Supports Celeron 633(66),667(66),700(66)MHz
CPUs

Maybe it is the fact that the Revision 1.1 supports higher Mhz PIII's that it give you the option to higher the core voltage so much?

If you don't know where to find your revision number, it is on the back of the bottom most ISA slot. Your suppost to take the motherboard out of the case to check it, but I just stuck a small mirror back there and managed to see it.

 

[Dexion]

No! I'm not saying your BIOS is not up-to-date.

There's a technique that can increase the the amount of voltage options for the BH6 by simply flashing the BIOS again when your CPU is set to 1.7volts. The BIOS thinks that the CPU @1.7 is default, and it will allow you to choose higher voltages. You can then set it to 1.8-1.85volts to get your system stable with Quake 2. My Celeron 566 would run at 875 w/ 1.85 to be rock solid, anything less the system would crash or hang.

 

[spamboy]

My 566 would not do 850 stably at a decent temp with the stick heatsink either. I got a Golden Orb and now I can do 884 and not overheat. Another point: You can set the multiplier to anything and it will still be 8.5

It doesn't matter what you set it to, it doesn't make a difference.

 

[SteveZombie]

That sounds kind of odd to me but I guess I will give it a go later tonight or tommorow.

 

[SteveZombie]

OK I set my voltage to 1.70 and reflashed my BIOS, surely enough it let me bring it upto 1.85! So now I have it running at 850Mhz with 1.85 core voltage and 3dmark 2000 didn't crash! I'm gonna continue testing and see how much I should lower the voltage. If I can get it to run fine at 850Mhz with 1.75 voltage or 1.8 should I try going for 112Mhz FSB? (I think 112Mhz is the next highest one, but I'm not totally sure...)

 

[Dexion]

So what do ya say hmm? LOL J/K

Congrats dude!

 

[heng1028]

from 100FSB to 112FSB, it is a big jump for your celery.

I have mine running at 103FSB (1.8v) and it did not post at 112FSB

I tried 1.9V that is the max for my mobo and no hope.

If you mobo support more FSB, you could try in between 103 and 112.

congrats that you get to 850.