Vcore tolerance

[Tocken]

Hello all, here's a question from a newbie:

The Vcore (1,5V) was very noisy (~0,5Vpp) on a 3-year-old Jetway MB (P4/2,6GHz), so I replaced 9x leaky GSC 1500uF/6,3V with 8x2200uF/6,3V.

With the new caps, there are still some noise <0,1Vpp.
The frequence of noise seems to increase when moving the mouse but the system feels much more stable now (no more freezes).

Anyone knows the tolerance of Vcore noise on a P4?

(sorry for my bad English)

[Per Hansson]

Re: Vcore tolerance

No idea, but check out the PSU too, you could also have badcaps on the +12v line...

[linuxguru]

Re: Vcore tolerance

What brand and series are the new 2200/6.3 caps? These have to be ultra-low ESR for the P4 Vcore rail. Recommended series are Rubycon MBZ/MCZ, Nichicon HZ, NCC KZG and Samxon GA (?).

[Brian C]

Re: Vcore tolerance

I would like to see the voltage waveform ... if u have.

[Fizzycapola]

Re: Vcore tolerance

0.1v fluctuation doesn't sound anything to be concerned about, I can remember all my brand new PC's mine and friends having around this ammount of fluctuation, if you used general grade capacitors, you may get it down to 0.05v perhaps with better caps.

[Tocken]

Re: Vcore tolerance

Sorry for my late reply...

linuxguru:
The new capacitors are Sanyo MV-WX 105°C.


Brian C:
Sorry but I used an old crt-scope and it's a little tricky to take snapshots of the waveform with my digital camera...
btw, the computer works fine now.

Thanks for your help, all of you.