Archived from groups: alt.comp.periphs.mainboard.asus (
More info?)
Paul,
I contacted Asus before installing the Celeron D because nothing was posted
on their CPU compatibility table. They confirmed via email that the
P4R800-VM PCB revision 1.03 and later did support the Celeron D. However the
bios needs flashing to V1005, published the day before. As I had a P4 2.8G
already installed it was no problem to flash the bios.
I fitted the Celeron D , booted, installed XP Home SP1a and its worked
reliably ever since, apart from the oscillating fan syndrome.
Unfortunately my digital multimeter is quite old and cannot measure above
200mA so I can't measure the Amps being drawn by the CPU. The VCore on the
box is V1.40. The mobo reads it as between V1.36 to V1.40. No problem there.
The mobo and CPU have been stressed with SIS SandraSoft for a continuous
period of eight hours without a problem. CPU temp averaged 54 degrees and
the mobo temp averaged 38 degrees, cooled by the Intel supplied fan &
heatsink. The PSU temp was within its thermal limits even after eight hours.
Don't get me wrong, it generated more heat than a small electric fan heater
but the mobo, CPU and PSU did not overheat and I had no stability problems.
But I had to open the window in the small room to let all the heat out!
My current perception is that the PSU maybe marginally underrated or its
reaction time to a demand for high amps is a little too slow, therefore I
get a volt drop on the 12V line. The fan rotates at 3000rpm at 12V when hot,
which translates to say a 15% drop in revs when the 12V line is loaded.
Hence the oscillating fan noise syndrome. Its sounds like a hamster revving
a small electric car - very irritating after 10 minutes.
It strange that I have not heard anything from Asus support today since I
reported my findings this morning. Maybe I've given them something to think
about.
Andy
"Paul" <nospam@needed.com> wrote in message
news:nospam-1407041654110001@192.168.1.177...
> In article <ojfJc.178$847.46@newsfe1-win.ntli.net>, "Andy"
> <andrewisstargazing@ntlworld.com> wrote:
>
> > Paul,
> >
> > Thanks for the suggestions
> >
> > I reported this problem to Asus support over a week ago and we exchange
> > emails daily on the subject.
> >
> > Great minds think alike. I have already attempted to power the fan
directly
> > from a hard drive connector as a test. It makes no difference. The fan
noise
> > still oscillates when the CPU is under load.
> >
> > Just checked the the 12V supply with a digital multimeter at a hard
drive
> > connector. The meter reads 11V with no CPU load and dipps below 10.5V
when
> > the CPU is under load. Asus probe measure the 12V line as 11.8V
> >
> > I have disconnected all the periferals i.e. DVDRW and the floppy.
Repeated
> > the test and the 12V supply still dips below 10.5V during CPU load.
Replaced
> > the PSU with another identially rated unit. Same result.
> >
> > The PSU is a 310W unit which can supply 198W from its 12V line i.e. 16A
as
> > specified. The only components the PSU is powering is the mobo, 1x256MB
> > PC3200, Celeron D 330 and its fan.
> >
> > I can only conclude that the CPU is drawing more that 16A from the PSU
to
> > drag down the volts. The rated power consumption of a Celeron D 330 is
> > approx 85W - no where near 198W!
> >
> > I emailed Asus support with this info this morning and asked what
capacity
> > of power supply they used to test the P4R800-VM with a Celeron D 330. No
> > response as of yet but I will keep you posted.
> >
> > I can't belive that the Celeron D 330 is draging more that 16A from the
12V
> > line. I know the new Prescott core needs more power and generates more
heat
> > that the Northwood but this is just getting silly. Just as a check I
> > refitted a Northwood P4 2.8G. The fan noise disappeared and the supply
does
> > not drop below 11V.
> >
> > Andy
> >
>
> Interesting. And, your report is the first user report of getting a
> Celeron D to work. Two other users couldn't get their boards to POST
> (on different boards).
>
> So, you've confirmed with the voltmeter, that the PSU is at fault.
> Or, at least it cannot supply the current the CeleronD is drawing.
> My cutoff for PSUs is somewhere between 5% and 10% dip below 12V
> nominal, and your measured value of 10.5 with a voltmeter is well
> below that.
>
> I use a clamp-on ammeter, to measure DC currents in wires like the
> two +12V wires on the 2x2 power connector. That connector is the
> one I'd be looking at, to determine if the processor draws current
> in spec or not. While you could try to find some Molex Minifit Jr
> plugs, and make an adapter cable for the amps input on the voltmeter,
> there is a danger that the current could be higher than the
> limited range of your meter. My meters here, have a limit of 10A
> on the ammeter ranges, and that might not be enough. My clamp-on
> ammeter can measure up to 400 amps DC or AC (because it is based
> on a Hall probe that measured the magnetic field, and doesn't touch
> the circuit).
>
> When you enter the BIOS monitor, does the Vcore value make sense
> for the VID value printed on the box the processor came in ?
> The Intel site had been listing the processor, as using around
> 1 volt, which is most likely wrong. Being related to other Prescott
> processors, it should be in the 1.25 to 1.4 range. I'm curious if
> perhaps the VID isn't being read properly by the Asus board.
>
> If the Vcore voltage is actually higher than it is supposed to be,
> that could cause excess consumption on the CeleronD. But, the heatsink
> would be overheating if that were the case. Does the CeleronD
> run extremely hot ?
>
> Hmmm. I wonder if the BIOS doesn't recognize the processor properly,
> if it will program the VID to an inappropriate value. We know
> that Asus BIOS don't like to undervolt. The BIOS generally will
> refuse to accept manual Vcore settings known to be less than the
> nominal VID values for a family of processors, so maybe the BIOS
> is messing about with Vcore and running it higher than the VID
> value being sent by the processor.
>
> In any case, logical thinking would be this. You have a 16A supply
> to work with at 12V. That is a total of 192 watts, and it is going
> somewhere. I would be using my fingers, to figure out exactly where
> the heat from that power ends up. Something has to get hot. Even
> the air coming out of the PSU should be hot, due to the excess
> current drain.
>
> In the case of a simple (partial) short, most of the heat could
> be dissipated in the PSU. But, because you've operated another
> processor in there just fine, that rules out that kind of fault.
>
> So, follow the heat...
>
> Paul
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