assistance with my overclock...

[Grand Monkey]

i can get my 2.8c P4 up to 3.3ghz stable and can run benchmarks all day, temps are at 30 degrees cel idle and 40 degrees load. now that says to me push some more, but as soon as i go up to 3.4 or 3.5 (my target!) i can boot but try running sandra burn in and it just freezes. now i know its not the temp so i'm trying to figure out if i am missing something or the chip won't go any further. i'm thinking it might be my power supply. suggestions?

Specs

Abit IC7-MAX3
P4 2.8ghz C
1gig corsair pc4000 ddr
ati 9800 pro 128 mb
Qtec 400w psu (useless i know!but cheap!)

oh and i have 1.55 core going through the cpu.

[Da_Rude_Baboon]

BigZ is the man to ask about overclocking but from your spec i would definetly say that the Qtec power supply is the weakest link in the chain. :mellow:

[Darv]

I don't know very much about P4 overclocking but I think you will want to try uping the v-core. That should make it more stable.

Also I would say a new PSU is in order. The reason Q-Tec PSU's are cheap is becasue they aren't veyr high quality. Try something like an Antec or if you want a silence a Zalman.

[////\oo/\\\\]

With those temps you can def up the v-core some more...

Incidently is 1.55v your setting or your reading? (use CPU-Z) I would try taking your v-core reading up to 1.6v in small steps and see what happens.

My v-core, though stable consistantly reads about 0.05v below the setting. :blink:

If that doesn't work you may well have to look at upgrading your PSU :(

[bigZ]

Have you got MBM5 grandmonkey?

If you could let me know what your lines are reading at full load, I'd be able to tell u if your PSU is a problem or not :)

One thing with P4's is they are very susceptable to high voltages... They tend to overclock to xxxGhz and then just stop, no matter how hard you try, they just won't go further. They have a very deep pipeline which is the reasoning for them not liking high voltages. I put some insane volts thru my Athlon XP's but, I don't think I'd put much more than 1.6v through a northwood, and 1.525v through a prescott due to their voltage dislikes.

They tend not to need much voltage anyway, they either clock well or don't :)

Check you've got a good contact with the CPU/Heatsink, this can often increase clocks a little. vDIMM and vDD can help too, you might find your clocks become a bit more stable with much more stable voltage.

The 3.3v line is where your vDIMM (memory voltage) comes from, so it's important to have a good 3.3v line if you're wanting to sustain good front side bus.

From what I've heard there is a bit of a problem with "droop" on the vCore on the motherboard you are using, so it's also important to have a good 12v line (main power for your vCore) :)

Hope this helps a bit.

[Grand Monkey]

ok, thanks for all the replies people, sorry i havn't replied sooner, i have been ill unfortunatley. anyway bigz i went and got mbm5 and here is a picture of the readout under load
http://server6.uploadit.org/files/GrandMonkey-mbm.jpg
the core readout actually drops to 1.49 on load just wasn't quite quick enough with my screen grab <_<

i'm thinking its the powers supply.

[Darv]

With your 3.3 line at 3.23 on load I would definatley say a new PSU is in order. Also your 12v line is quite low.

I just got my self a new Zalman PSU and can recomend it. Lines are great and its silent :wub:

[Grand Monkey]

does zalman do psu's above 400w? think i'd need more than that, was looking at an antec true power 550w. heard good things about them. hopeing that might solve the drop i get on the vcore too.

[bigZ]

your 3.3v and 12v lines are like mine, pretty bad, it hinders me with my overclocking certainly. I'm modding my PSU soon to give me better lines (it's only an external PSU mod, I'm not mad enough to go inside the PSU cover) :p

However your 3.3v line is OK providing it is +0.3v above vDDR, corsair is within warranty up to 2.8v I think, so you can take it to 2.8v no problem, don't worry if it's overreading slightly, there is a +/- 5% rule on memory warranty :) I run my memory at 2.98v 24/7 and it doesn't even get close to getting warm, it's actually cold to touch the heatspreaders :)

Core voltage drops under load, you've just got to make sure it doesn't drop too far, I guess your set voltage is 1.525v?

[Grand Monkey]

yes my core voltage is set at 1.525v. so are we guessing it is my lines that our causing problems. its just annoys me cos it boots at 3.5 ghz and it gets me all happy, but i need to make it stable!
actually just noticed that i was running 1.55 core voltage and it was dropping to 1.5.

[Darv]

Originally posted by Grand Monkey@Mar 3 2004, 12:41 PM
does zalman do psu's above 400w? think i'd need more than that, was looking at an antec true power 550w. heard good things about them. hopeing that might solve the drop i get on the vcore too.
No they only go up to 400w but I think most people would find thats enough.

Of course if you really want more most people would suggest the Antec ones.

[////\oo/\\\\]

Originally posted by bigZ@Mar 3 2004, 12:46 PM
(it's only an external PSU mod, I'm not mad enough to go inside the PSU cover) :p
Yet! :lol: :p

[Da_Rude_Baboon]

I can second Darv with the Zalman PSU its solid as a rock and very quiet. ;) You'll find that a quality 400w PSU will often out perform a lot of 500W+ PSU from lesser manufacturer but you cant go wrong with an Antec.

Bear in mind that with the shift to BTX form factor for motherboards over the next couple of years the current PSU will become redundant so dont buy anything way over powered.

[bigZ]

macro has just done a review on the Zalman, it looks good apart from the 12v line :)

http://www.bit-tech.net/review/299

[Grand Monkey]

ohhh i like the Global Win SAF520, that would look nice in my case!

[fillip]

i'm more tempted by the Tagan supply TBH.
quieter, doesnt look as purdy as the globalwin but it's got a tonne of headroom @ 480watt.

Not a bad price either - saw it @ Scan (http://web6.scan.co.uk/Products/Info.asp?WPID=82572) for under £60 - not bad!

[fillip]

Originally posted by Da_Rude_Baboon@Mar 4 2004, 08:51 AM


Bear in mind that with the shift to BTX form factor for motherboards over the next couple of years the current PSU will become redundant so dont buy anything way over powered.
Not so my padawan friend, you have much to learn...

BTX form factor is largely incompatible with the ATX form factor - the only area where this doesn't fully apply is in power supply support, as you can use ATX power supplies with BTX motherboards

source = AnandTech (http://www.anandtech.com/showdoc.html?i=1876&p=2)