power supply recomendations please

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what do we need as far as a psu for this machine?

computer spec:
Case        COOL MASTER ELITE 330
Motherboards    Gigabyte P35-DS3L ATX
Processor    INTEL CORE 2 DUO E6850
Memory        4 gigabytes    ddr 667
Hard Disks    SAM 500GB SATAII HDD x3 units
Sound        SoundBlaster Xfi elite pro
Video        Gigabyte 8800GTX 768 meg
Keyboard    ms key mouse wireless desktop 6000
Monitor        Samsung 24 wide 244T
Card reader    Generic
OS        XP HOME SP2+
usb port     up to total 12    Generic - integrated


Re: power supply recomendations please

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I am going to build a new system shortly and will be getting something
similar to this.  Whatever I get will be over 600 watts and have a few good
reviews   so it will be a well known brand.

Anyway do a search for PSU reviews and see what you come up with

But it doesnt mean that the PSU is your problem .

Re: power supply recomendations please

scully wrote:
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Antec or Delta... depending on your preference.

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Re: power supply recomendations please

scully wrote:
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My choices for your hardware would be the Seasonic S12 SS-650HT,
Corsair HX620W or the Zippy GSM-6600P.

If you plan to use a TEC or add another 8800GTX these choices are invalid.

Re: power supply recomendations please

scully wrote:
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A decent 400W should have no problem with that.  www.jonnyguru.com,
www.hardocp.com, and www.silentPCreview.com all do proper reviews, and
HardOCP recently ran one for budget PSUs.

If you buy Antec, try to avoid the SmartPower and TruePower lines
because they're made by Channel Well Technology and contain lots of
bad Fuhjyyu brand capacitors.  Better are their Basiq (by Fortron-
Source) and Earthwatts, Trio, and NeoHE series, all which are by

Seasonic, Fortron-Source, Delta, Zippy, Etasis/Silverstone, and
Enermax are some good manufacturers

Re: power supply recomendations please

On Thu, 01 Nov 2007 13:52:56 -0700, larry moe 'n curly

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thank you all for your input especially paul for your very detailed
analysis - i will probably use
seasonic x900 or silverstone st85zf - both same price

Re: power supply recomendations please

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For a similar system I got an Antec Earthwatts 500.

Re: power supply recomendations please

I would highly recommend getting at LEAST an Antec 750 Watt PSU.  You have a
lot of current demanding components in their.  Enjoy it!


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Re: power supply recomendations please

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well after testing
ram ok tried different psu and minimum config and it failed all tests
all that is left is to replace mainboard - pooh!! -
under warranty 10 days to "repair" - board is in service 30 days only

Re: power supply recomendations please

DaveW wrote:

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750W???   For just a Core 2 Duo E6850, three 500GB HDs, and an 8800GTX
graphics card?  That's ridiculous.  Any good 500W PSU with at least
30A @ 12V power available for the graphics should be fine, meaning
about any good 500W PSU with an actual single-rail +12V of at least
35-40A should do. I would look for SLi approval (not just an SLi
connector) at www.nVidia.com and Crossfire approval at www.ati.com.

Re: power supply recomendations please

scully wrote:
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12V @ 1.5A, 5V @ 1.5A  Estimate for an optical drive.

Hard drive 12V @ 0.6, 5V @ 1A (had to make this one up - web sites are crappy)
Hard drive peak startup current 12V @ 2.5A for first 10 seconds (Seagate)
Samsung - no specs.

E6850 - 65W / 12V * (1 / 0.90) = 12V2_current = 6.02A at 90% Vcore efficiency

RAM 3.4W per stick, 13.6W total

Motherboard - adjusted to make a total of 50W for mobo and RAM, so 36.4W :-)
Hard to get numbers for this.

Gigabyte 8800GTX - three sources totals 127.6W / 12V = 10.6A

Soundblaster - allocate 5W

Add them up.

Two opticals  (12V @ 1.5A)x2  (5V @ 1.5A)x2   Total 12V1 @ 3.0A  plus 15W for
lower rails
Three HDD     (12V @ 0.6A)x3  (5V @ 1A)x3     Total 12V1 @ 1.8A  plus 15W for
lower rails
Fans           12V @ 0.5A estimated           Total 12V1 @ 0.5A  (for three
small fans)
RAM                                                              13.6W for lower
Motherboard                                                      36.4W for lower
Soundblaster                                                      5  W for lower
Processor      12V @ 6.02A                    Total 12V2 @ 6.02A
8800GTX        12V @ 10.6A   (3.3V @ ~1A)     Total 12V1 @ 10.6A   3W for lower
Standby 5VSB                                                       5W for lower

Grand total:  12V2 @  6.02A  \_ 263W + 93W = 356W total power
               12V1 @ 15.9A   /
               93W for lower rails

The above assumes:

1) Both optical drives burning at the same time. Not really likely. Could drop
    power from one unit for a more realistic estimate. Say gaming with key disk
    into one of the drives.
2) Estimate is developed, assuming a gaming situation, with maxed 3D and
3) A second test case, is the first 10 seconds of operation. The three hard
    could draw up to 2.5A starting current each. But, at idle, the video card
drops by
    5 amps, and the processor current is also much lower. So in this case, there
    is no point doing a second calculation of startup current levels. It will be
    less than the gaming test case.

What does "lower rails" mean ?

3.3V and 5V are examples of lower rails. The motherboard designer could use
Usually, the two of them have a combined power rating in watts, and each output
an ampere limit. By the time you buy a big enough supply to run the video card,
usually the "lower rails" are big enough to do the job. My cutoff for them, is
at about 3.3V @ 20A, and 5V @ 20A. In the case of this build, the 93W number
makes me want to aim a bit higher. 25A to 30A would probably cover it, in the
sense that then, I no longer care which rail it all comes from. I've measured
a couple motherboards, and in fact, designs can vary wildly (one used 3.3V and
the other leaned on 5V).

The 12V rails are not "balanced" in any sense. In terms of value for money,
a power supply with a single rail, makes better use of the amperage capability.
The 12V1 at 16 amps, means you might get a supply with 12V1 @ 16A and 12V2 @ 16A
and the 12V2 is hardly loaded at all. If you had a 130W processor, the balance
would be a bit better, and an ATX 2.0+ type supply wouldn't seem like such a
stupid purchase.

In this case, the connectors also play a role. We need a pair of 2x3 PCI Express
connectors, judging by pictures of 8800GTX on Newegg.

OK, now to analyse a supply for acceptable characteristics.

ENERMAX EG495AX-VE FMA ATX12V Ver 2.2 485W Power Supply   $80 (and there is a
+3.3V@32A,+5V@32A,+12V1@22A,+12V2@22A,-12V@0.6A, +5VSB@3A
170W max on 3.3/5  384W max on 12V1/12V2  485W max for full supply.

The 3.3V and 5V peak ratings are excellent, and even if the entire 93W of
the lower rails came from either output, it would be handled with ease.
Similarly, the 170W max is greater than the 93W load.

On 12V, our total power is 263W. This is less than the 384W limit. Using
about 2/3rds of the capacity here. 12V1 is rated 22A, and the load is 15.9A,
so that one is OK.

Total system power is 356W and that is less than 485W. The supply is
basically running at 75% of total capacity, which is high, but would be
OK if the unit was a quality design (i.e. a $20 500W supply would pop if
you did this).

The only concern I might have, is the second reviewer (running an 8800GTS)
commented about the exhaust temp of the PSU. That supply does not have a
stated efficiency, and it could be 70%. But searching for an 80%
efficient supply, generally adds quite a bit to the price. But it is
only $80 (less after rebate).

This thing is currently $120. I picked this one, because I got tired of
looking at quad rail supplies on Newegg. This has one output rail and
is labeled as such. Other supplies cheat and you never know for sure how
they are constructed. And I'm not going to waste my time looking for a
reviewer who has opened each one up. For $40 more, you get a more
efficient supply, with perhaps a lower operating temp. If the manufacturers
of quad rail supplies would document them, there'd be more recommendations
for them.

+3.3V @ 24A +5V @ 30A  +12V @ 49A  -12V @ 0.8A  +5VSB @ 3A  83% efficient
http://www.pcpower.com/prices /


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