Hi,
Has anyone built a system with a ASUS PC-DL Deluxe mobo (for twin
Xeon)? I'm trying to find out if I can use my existing PSU (350W
Chieftec dragon standard ATX PSU). I've read that the 20 pin
connector I have will work on the 24 pin socket (p. 54 of the manual
seems to back this up), I'm not so sure about using the 4 pin
connector on the 8 pin socket. Has anyone done this? Or do I need to
buy some kind of plug converters? Or a whole new PSU...
Thanks,
Simon
Work out the current required on +12V for yourself.
processorfinder.intel.com has info on processors. Select Xeon. Here
is a typical entry - a 3.06GHz/FSB533/L3=1MB
http://processorfinder.intel.com/sc...cFam=528&PkgType=ALL&SysBusSpd=ALL&CorSpd=ALL
It draws 87 watts, which will come from a Vcore circuit. Assume
the Vcore is 90% efficient. That raises the input power to the
circuit to 87/0.9=97 watts. The power comes from +12V. So,
that is roughly 8 amps. Multiply by two for two processors.
Now you are at 16 amps. Add 1.5 amps for 12V fans, 0.5 amps
for one disk drive, 0.5 amps for a CD, 1 amps for ATI9800 aux
power 12V feed. Total is 19.5 amps. For reasonable long life,
the PSU should have a slightly higher rating, like maybe 24
amps, and if you plan on adding more +12V hardware, add that
in too.
Now, check the label on the Chieftec 350W power supply. Does
it do 20 amps on +12V. Not likely, if it is a 350W supply. The
Antec Truepower series does 17 or 18 amps at that power level,
and there is no reason to expect the Chieftec desktop PSU to
be ready to do server duty.
Assuming all the above is true, it would be suicide for the PSU
for you to use adapters to plug it in. If you only planned on
using one processor, it might work, but would not be recommended
for two processors.
If you are interested in adapters, this page shows some Minifit Jr
connectors used for PCs. For example, a 39-01-2200 is used for the
20 pin connector on a PSU. There are also 8 and 24 pin connectors
listed in the same section of table. You would need some pins from
the bottom left of the page, some heavy stranded wire etc. To build
the 8 pin power connector, you are feeding 16 amps, and a drive
power connector is rated for a max of 8 amps, on its single +12V pin.
The voltage drop in a drive power cable might not be too good at
that kind of current. So, two separate drive cables would be needed
at a minimum, for the processors I selected in the above example.
Processors faster than the 3.06, would mean a third drive connector
would be needed, or really a fourth, as you need a symmetric way to
map source cables to the pins on the connectors. I doubt your PSU
has any cables left at that point.
http://dkc3.digikey.com/PDF/T042/0104.pdf
My gut tells me you are better off with a real power supply. No
sense killing a PSU and when it dies, some out of spec voltage
damaging your new board.
You can see a couple of brands mentioned here. I don't really
like descriptions that list 12V1, 12V2, 12V3 etc., implying
separate output circuits, because you don't know how the separate
output circuits are split across the loads. Logically, two groups
of four pins on the eight pin connector, could be on separate
outputs, but you still want enough power on each one, to take any
Xeon you throw at it. The loads are Xeon1, Xeon2, motherboard_fans
via 12V wire(s) on main connector, and disk_drives, and the outputs
of any supply have to be fitted to those loads. I would hope the
Asus design, separates the 12V pins on Xeon1 from Xeon2 (there is
no reason for them to be common).
http://castle.pricewatch.com/search/search.idq?qc="SSI"*+AND+"PSU"*&cr=ssi+psu
The motherboard list here suggests the 510XE ($200),
for a premium supply.
http://www.pcpowerandcooling.com/pr.../maxperformance/turbocools/index_hp_atx-3.htm
Leythos can probably tell you what the good power supplies are, as
he has built a number of these boards up.
HTH,
Paul
