Overclock problems

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wjcros

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Ok i was helping my friend overclock his computer. he has an ECS K7S5A with a Athlon XP 1600+ to it. Now if you know any thing about this board you knew that u would have to update the bios in order to adjust the bus speed. well stock the computer had the bus set at 133MHz and the smallest increment you could increase it to was 166Mhz. so i set the bus to 166Mhz and rebooted and the computer did nothing what so ever. So i figured all i would have to do is to flash the bios...right? well after flashing i was still gettin the same problem. so i am now leaving the CMOS battery out for about 24 hours hoping that this will correct the problem. but does any one else have any other suggestions. i just hope not the cpu is fried.
 
Should just put the CMOS pin from 1-2 to 2-3 for a few seconds and that would have cleared the CMOS instead of having to leave the battery out for 24 hours.

And yeah I think I can pretty much tell you why you can overclock right off the bat.

If you don't have a spot in the BIOS where you can lock the AGP/PCI bus (locking the AGP at 66MHz automatically locks the PCI so mainly you just need to lock the AGP frequency at 66MHz)
then you can't OC your CPU's FSB

The CPU:AGP:pCI are all on a ratio together.

A CPU with stock 133FSB has a CPU:AGP:pCI ratio of 4:2:1 which is in this case 133:66:33

Once you raise your FSB to 166 it becomes 166:83:41.75

The 83MHz is WAAAAAAY too high for an AGP bus frequency. This is why you always have to lock it at 66MHz because the AGP really doesn't like going beyond 72MHz or so.

You need a board where you can lock the AGP Bus if you want to OC the CPU through the FSB...otherwise your only option to raising the clock speed is upping the multiplier.

EDIT: The CPU should be fine though. I put my CPU at 2.8GHz with 2.225 Vcore which is the max my board could deliver and it survived that :p I'm pretty sure his will be ok. Back when I didn't know ANYTHING about computers I simply set my 2400+ XP from 133 to 166 thinking 'well if 133 is good 166 is better' and it survived that
 
The CPU:AGP:pCI are all on a ratio together.

A CPU with stock 133FSB has a CPU:AGP:pCI ratio of 4:2:1 which is in this case 133:66:33

Once you raise your FSB to 166 it becomes 166:83:41.75


hey nubius can you try to explain to me how you worked out these numbers im a little confused cheers,
 
Well based upon what the FSB of the CPU is the AGP:pCI have to be on a certain ratio to it.

The AGP:pCI will always be 66:33 so when it comes to the CPU it's just basic mathematics.

In his case like I said it's CPU:AGP:pCI is 133:66:33 that's normal, because the CPU is 133FSB, when the CPU is 4:2 that means that the CPU should be twice that of the AGP

66x2 = 133, the CPU's fsb(FSB in the BIOS, obviously the actual FSB is 266)

same thing applies to the AGP:pCI, the AGP is twice that of the PCI since it is a 2:1 ratio. 33x2 = 66

In the case of say a 166(333FSB) it'd be a different ratio like 5:2:1, or in the case of a 200(400FSB) CPU it'd be 6:2:1

The CPU FSB of 200 is 3 times as much as the AGP in this case, so with a 6:2 that means the CPU is...just like I said...3 times as high as what the AGP should be and then of course the normal AGP:pCI is 2:1


I'm a really bad teacher especially when it comes to explaining the FSBs and numbers and whatnot, so if you still don't understand let me know.
 
sorry i wasnt specific enough. i know that moving the jumpers resets the bois. and i did do that. several times but still the computer does nothing on reboot. and on a totally different computer when i overclock it too high it does this as well but when i reboot again it automatically resets to the defaults. but still what could be wrong w/ this computer i was just hoping that the jumper was bad and that by leaving the battery out the cmos would b cleared. im just hoping that the cpu isnt fried.
 
Ohhhh I see......well hmm, I guess at this point you just gotta wait with the CMOS battery out and see if that clears the CMOS.

Also, the way I go about resetting my CMOS is (and this is in no means an 'official' way of doing it, infact some may argue it does damage, but I've done it this way for years without consequence) turn the PSU off via the switch in the back ( or unplug it if yours doesnt have the switch) then put the jumper to pins 2-3 the clearing position. Meanwhile the battery is still in, flip the switch on the PSU , don't boot the computer or anything, just turn the PSU on , wait a couple seconds, turn it back off, put the pins back to default 1-2, turn PSU back on and boot up the machine.

I don't know if you fried the CPU though, I'm thinking you probably didn't because I've done the same thing before and worse to CPU's and they've lived. Unless by chance of course that it really didn't like that initial surge of power and being that it's a little older, didn't like the shock.

Surely hope thats not the case for you though
 
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