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Discussion Starter · #1 ·
Howdy y'all, quick question(s)..
I recently built a new phenom II 555 system, and proceeded to
overclock it.
I used a vcore of 1.5125 volts, bus speed of 225, and a multiplier of 17.5
giving me a stable core clock of 3937mhz, with one core unlocked.

I heard a few places that after a core unlock the temperature sensor on the cpu
becomes incorrect, but the pc probe software that came with my asus m4a79xtd evo motherboard seems to be giving me accurate readings of 40c idle 48c maximum load. Is this incorrect? My BIOS gives me a reading of 41c.

Also, idling, my voltage hovers around 1.51 volts according to cpu-z,
but under load it drops to 1.478 volts.. What's going on?


Overclocking newbie here btw.
 

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i believe your Vcore is high for that chip... voltage for that chip looks to be 1.40v at max. you will need to drop it down before you damage the chip.

there is a lot of research you need to do BEFORE attempting to OC. trying to OC without basic knowledge of safe temps and voltages is very dangerous for your computer

48*C at nearly 4.0ghz seems to be very low, what type of cooling are you using? temperatures can get dangerous when OCing and raising voltages.

also, when your CPU is put under load, it is normal for the voltage to drop slightly.

you should have asked these questions before you attempted to OC.

we are all here to help you, so dont take this personally. we, as an OCing community, dont want to see you damage your computer.
 

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Discussion Starter · #3 ·
I read that the nominal voltage for the 555 is between .8125 and 1.4 volts, but I thought it would be safe to go .1 over.. What do you think?

Also, thanks for the reply!
 

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its definately not safe. voltages are regulated very closely with CPUs, down to the thousandths or ten-thousandths of a volt

.1v is actually a fairly large jump in voltage when it comes to CPUs.

you will need to drop your voltage to a safe level and get a more accurate way to monitor temperatures before continuing.

i would reset your CPU to the default settings so you dont damage anything while we are trying to help you with your OC

also, thanks for filling out your signiture with your rig, there is no need to be redundant tho. just fill in the system specs so we know what hardware youre working with.
 

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Discussion Starter · #7 ·
I know it's a bit of a lame source but I remember reading at tom's hardware that 1.5v was relatively safe for 555's. Also, I believe my proc ran at either 1.35 or 1.4 volts stock, so perhaps its not as large of a jump as you had percieved. Not to contradict, just putting my 2 cents in.
 

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Discussion Starter · #8 ·
Oh also noticed that system specs are posted beneath the sig, lol. I removed them, thanks.
[edit]
Oops sorry for double posting.
 

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That vcore is 100% safe. Most people recommend 1.55v as the max 24/7 safe voltage for Phenom II, but I wouldn't be afraid of even running 1.6v. Phenom II can really handle voltage well, unlike 45nm Intel CPUs.

Anyway, try Everest for reading CPU temp. When I had an unlocked 550, it read it perfectly. For some reason I always had luck with it when others failed.
 

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Quote:

Originally Posted by Dopamin3 View Post
That vcore is 100% safe. Most people recommend 1.55v as the max 24/7 safe voltage for Phenom II, but I wouldn't be afraid of even running 1.6v. Phenom II can really handle voltage well, unlike 45nm Intel CPUs.

Anyway, try Everest for reading CPU temp. When I had an unlocked 550, it read it perfectly. For some reason I always had luck with it when others failed.
+1
but unless you have adequate cooling first..
i tried 1.6v on my b55 quad
prime95 70+C LOL
 

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well its c3 stepping. they are a much better chip the the c2. mine is at 1.3v and 3.6ghz. so it shouldnt need more than 1.4 maximum to hit 4. so i think you should lower your vcore down to about 1.4 or till it gets unstable and raise it a little bit until it is.

oh and if you have a standard heatsink you shouldnt be up that high anyway
 

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Quote:

Originally Posted by Th0m0_202 View Post
well its c3 stepping. they are a much better chip the the c2. mine is at 1.3v and 3.6ghz. so it shouldnt need more than 1.4 maximum to hit 4. so i think you should lower your vcore down to about 1.4 or till it gets unstable and raise it a little bit until it is.

oh and if you have a standard heatsink you shouldnt be up that high anyway
tat depends on how lucky with your chip
mine can hit 1.4v fully prime stable at 3.8ghz
but require 1.475v for 3.9ghz
its also depends on your mobo.. seriously.
my fren help me with overclocking my b55 quad and he got to 3.9ghz at 1.412v wif an el cheapo hyper 212+ which he sold me lol.
but he used a msi 790gx-gd70
 

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Man every chip is different you can't tell anyone where they should be at or what is too high/too low. 1.4v for 4ghz isn't going to happen I don't think even on a really good C3 batch. Voltage doesn't scale like that. Personally I needed 1.5v for 3.9ghz and I think around 1.55v for 4ghz but this was on a C2.

Don't look at AMD's whitepapers for max safe voltage... If you want to look at AMD's specs, you should look at the frequency; and no processor they make is intended to be ran faster than the stock frequency. Max memory is also only 1333mhz in two banks, and 1066mhz in 4 banks.

The most commonly agreed on safe voltage is 1.55v. I say don't even be scared to go a little higher. But really, you are fine where you're at.

Quote:
And AMD does not recommend voltages above 1.55V for overclocking with air cooling. However, even Phenom II X4 940 requires no more than 1.35V in the nominal mode, which leaves a considerable margin for safe voltage increase.
http://ixbtlabs.com/articles3/cpu/ph...ocking-p1.html

And that is talking about C2 stepping. If anything, C3 may actually handle voltages better I would imagine.
 

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Discussion Starter · #14 ·
Quote:

Originally Posted by terence52 View Post
+1
but unless you have adequate cooling first..
i tried 1.6v on my b55 quad
prime95 70+C LOL
I've got a nice cooler(by my standards lol) and some proper thermal paste sitting on top of the 555 right now.. Do you think I should push for 1.6v 4.2Ghz? my load temp is 48 c in prime95

Also, thanks Dopamin3 and terence52
 
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Quote:

Originally Posted by Saucy View Post
I've got a nice cooler and some proper thermal paste sitting on top of the 555 right now.. Do you think I should push for 1.6v 4.2Ghz? my load temp is 48 c in prime95
I would just try 1.55v and see how high you can get it. 4.1ghz ish should be achievable I would guess.

But the real fun on AMD platform is NB frequency and RAM timings. I would clock your RAM less than 1600mhz, maybe around 1200mhz-1400mhz depending on the kit you have; and then tighten the timings as much as you can. Don't be afraid to overvolt the RAM a little because AMD doesn't have a silly voltage limit on the memory of 1.65v like core i3/5/7 processors. Drop your HT Link multi and have it as close to 2000mhz as you can. HT Link really doesn't do anything and sometimes adversely effects performance. Then up your CPU-NB to like 1.35v-1.4v, maybe bump your NB voltage a tad, and start cranking that NB frequency multi. Shoot for at least 2.5ghz, and from what I've seen 2.8ghz should be achievable with tweaking.
 

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Quote:

Originally Posted by Saucy View Post
I've got a nice cooler(by my standards lol) and some proper thermal paste sitting on top of the 555 right now.. Do you think I should push for 1.6v 4.2Ghz? my load temp is 48 c in prime95

Also, thanks Dopamin3 and terence52
nice load temps..
i think u can but more likely u will want to drop the voltage and clocks for 24/7 usage
btw try using at hardware monitor to see your ihs temps.
should be tmpin 1 for your proc.
 

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the C3 revisions of PhII say its safe to 1.55v, so you can probably go up to that. i was just going off AMD's info for the 555 at 1.4v.

AMDs are a little tougher when it comes to voltage, but make sure youre on top of the temps!
 

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Discussion Starter · #19 ·
Hello again guys, I'm tinkering around in the bios again, can't seem to get a stable 4.1 or 4.2ghz overclock on 1.55 volts with bus speed 225 18-19x Multiplier. I scaled it back to 18x mult 223 bus running prime 95 now


Quote:
the C3 revisions of PhII say its safe to 1.55v, so you can probably go up to that. i was just going off AMD's info for the 555 at 1.4v.

AMDs are a little tougher when it comes to voltage, but make sure youre on top of the temps!
Thanks!
 
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