voltage for a p4?

watchinthewheel

watchinthewheel

watchinthewheel

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24 Sep 2005
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im running a p4 775 3ghz at 3.6 at the moment but i have read that my chip is capable of a clock of 3.9! i have tried upping the frequency but it becomes unstable at about 3.7, could this be caused by having too low a voltage? I know its not heat as it doesnt go past about 45c under load. If it is voltage is there any guide as to how much that can be upped? do you just judge by heat or is there a more concrete method? I have already upped it a bit but dont want to go too far as i can't afford to replace the cpu if i fry it!

mobo-epox 5lwa
cpu-p4 3ghz (775)
ram-pc24200 ocz platinum limited edition.

any advice is much appreciated, thanks :)
 
thanks for the reply. to be honest i have no idea what sort it is, i got it off ebay a few months ago and didnt check, i would guess its a 530 though, would that make a big difference to overclocking?
 
watchinthewheel said:
thanks for the reply. to be honest i have no idea what sort it is, i got it off ebay a few months ago and didnt check, i would guess its a 530 though, would that make a big difference to overclocking?
Click to expand...
Download this, it'll tell you everything about your CPU etc.

In my experience, 630s clock better than 530s but you should reach about 4Ghz.
 
wow thanks for the link, thats a really usefull little program.

i was right its a 530, heres all the other info.

name: p4 530
code name: prescott
package:LGA775
voltage:1.3 (its safe to take this up to 1.5?)
Family: F
Model: 3
Stepping: 4 (what does this mean?)

Ram:

fq:269.1Mhz
Ratio 3:4
cas: 4 (i can get this down to 3 but havent updated the bios yet)
ras/cas: 4 (can reduce to 2)
Ras precharge: 8 (cant change due to instability)


are you sure that my chip will be able to run at 4Ghz! im having real trouble getting it passed 3.6, if i clock it higher then the system becomes unstable, and if i up the voltage much more i get temps of 50c idle!
 
Yes, 1.5 is safe but I like to stay around 1.45v for normal useage. Temps are OK up to about 65C load.

Update your BIOS, that RAM (which I presume is the same 3-2-2-8 as mine) is awesome and should be OK at 300Mhz at those timings with enough volts. (Warrantee is fine for up to 2.2, mine needs 2.1 for stability at that speed)

Is there a letter in front of that stepping number?
 
ok, well im not up to 1.5v yet anyway its just good to know where the limits are.

i have heard thats its really good ram, which is good because it took me ages to pick it and seemed the best. I have only just updated my bios though, perhaps a week ago, it was the latest one on the epox site. I have cleared it (changed jumpers to clear cmos) since but i thought that just resored the settings not changed back to the old bios, if it does that it is a major pain having to reflash every time it wont boot!

theres no letter in front of the stepping number, what is that?

finaly, and this is a strange one, my bios tweaks have stopped registering. I cant understand it, i go into setup and change the settings as i always do, save and exit, it restarts and any changes i made appear in the post. Then windows boots and all my changes regarding the cpu have vanished, its back to its 3.0ghz. cpu-z says the same so its not a problem with windows. If i change the ram timings thats stored but nothing re the clock. If i reset though the bios still has the changes and hasnt reset to 3.0. is there some reason that this would happen, im really confused!
 
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Check you put the CMOS jumper back on correctly, and it only restores the default values it cannot flash the bios back to the old one.

There's usually a letter infront of the stepping, and is a good indicator of how well the chip will clock.

When you flash the bios, always flash it twice just to ensure it's done everything correctly.

If you can find an older BIOS then try that, maybe the one previous to the new one you're using, if you still have the settings problem then I'm not really sure what's up. Check the jumper first though.
 
yeh i thought it was the jumper first time i saw what was happening, but nope its right, plus its saving the bios from one boot to the next not wiping it ever time. boy am i glad it doesnt reflash every time you reset it, you had me worried there!

I will try reflashing with an older bios and report back.

has anyone out there seen this happen before, i didnt even know it was possible to make changes to the bios and them be ignored in the boot sequence somehow! :confused:

oh and nope theres definaly no letter in front of the stepping, all it says around it is:

Model: 3
Family: F
Ext. Family: 0
Ext. Model: 0
Revision D0
 
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ok now its just getting weird! i reflashed the bios with an older version but it didnt do a thing! my changes were still there clock speed and everything, but it is still ignoring them! im utterly stummped I will try reflashing agin to the newer bios and hope that will shock it into working :confused:

tried it agian and reflashed the newer of the 2 bios's still nothing, no matter what i do it wont have it! it wont change the fsb. but any tweaks in setup for anything else (eg ram timings) it accepts. :confused:
 
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OK, try a "mega re-set of doom" by which I mean remove the battery on the motherboard for a few minutes, press the powerbutton as well for good measure, then replace the battery and try again.

I must say this is quite odd.
 
wont that wipe the bios? i may just be being thick but if it does wipe the bios doesnt that mean that it wont boot, and you need a hardware solution to reflash? if it does i cant do it because i havent got anything like that.
 
It's just a more thorough way of clearing CMOS. The BIOS itself is on a ROM chip, like a flash memory card, you don't lose your data when it's not getting power. Don't worry about losing your BIOS, it won't happen unless something MAJOR happens like you smash the chip with a large hammer.
 
Just looked at CPU-Z and it seems I should have been looking for the revision. Your's is D0 which probably isn't the best clocker and may not reach 4Ghz, but sould still reach a decent speed.

As for the BIOS problem, the only other thing I can suggest is try the PC with minimal components attatched. Just one stick of RAM, no PCI cards, one HDD.. the bare minimum. See if that helps, and see if it works with either stick of RAM.
 
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