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PC Hardware forum

General discussion

PSU question - So WATT ???

by mr_tinka / February 12, 2006 11:53 PM PST

Hi I'm building my own PC and I require a suitable power supply. The spec is:

Pentium 4 @ 3.0Ghz
GeForce Nvidia 6600GT
1 CD-DVD burner
2x hard drives
a few usb devices
1 PCI card for video capture

I think this will require no less than 350W. A local shop has no 400W units but they do have a 500W unit on special offer (cheaper than the 350W they stock). I was hoping to get a 400W unit. Will it be OK to use a 500W unit even if it's full potential is not required? Will it overload my motherboard????

Discussion is locked
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Yep, evcen if the 500 watter is
by Ray Harinec / February 13, 2006 12:46 AM PST

a cheapie and can't deliver 500 watts continuously, it will have sufficient margin to handle your system easily.

Nowadays one must be certain if the power supply has all the connectors that you may need if you go in for the SLI type systems. The new video cards need special power and connectors.

Make certain the the main mobo power connector is a combo 20/24 pin connector. That way if you have a 20 pin you simply detach the extra four pins, but if you later upgrade to a new mobo that uses the 24 pin, you can simply reattach the extra four pins.

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My mobo...
by mr_tinka / February 13, 2006 12:59 AM PST

Ok I think I follow, however I don't know much about these things. I have the motherboard already (an Intel 915GUX).

See pic (warning it's quite large):
http://www.intel.com/design/motherbd/ux/pix/d915gux_lg.jpg

The main power socket has 24 pins (left of pic). There is also a square 4 pin socket and a rectangle 4 pin socket (right of pic). Is there any special requirements I should look out for in the PSU?

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The square four pin is for
by Ray Harinec / February 13, 2006 2:51 AM PST
In reply to: My mobo...

the 12 volts that is now used to provide power to the CPU's regulators.

The mobo manual should describe what the other pins/sockets are for. I'm not certain what the connector next to the 4 pin connector is for, the one that you say is 4 pin rectangular.

I assume that you have SATA connections, and newer power supplies all seem to supply a few power connections for SATA drives.

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PWR
by mr_tinka / February 13, 2006 7:52 PM PST

The motherboard has been used previously and didn't come with a manual. Will look online for docs.

The square one has '12V PWR' printed next to it. The rectangular one has '1x4 PWR' printed next to it and looks like the power socked on the back of optical drives (male connector - 4 pin).

I've noticed SATA printed on it somewhere (I'm at work so I can't look. What is SATA?

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Alt PWR
by mr_tinka / February 13, 2006 7:55 PM PST
In reply to: PWR

Look at docs online. The rectagle 4 pin power socket is the alternative power connector.

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Alt PWR
by mr_tinka / February 13, 2006 8:21 PM PST
In reply to: Alt PWR

Just been reading up and I'm a whole lot wiser. The 1x4 PWR is if the main power connector on the PSU is a 2x10 connector, the 1x4 is then required. The 1x4 connector is not required with a 2x12 connector.

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Do you not buy over the inet??
by Ray Harinec / February 13, 2006 3:06 AM PST
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I do buy on net.
by mr_tinka / February 13, 2006 7:43 PM PST

I'm in UK. I do buy from the net. Bought a small micro ATX "P4" case to find the power supply is 150W stamped Aug 2000. The case is nice though. Got to pay for a new PSU and want it ASAP.

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If
by Bob__B / February 13, 2006 5:28 AM PST

your LOCAL SHOP has a good price on a 500w unit...go for it.

If for some reason it does not fit you can bring it back to your LOCAL SHOP.

A larger than needed psu does no harm.

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Cheers Bob !!
by mr_tinka / February 13, 2006 7:45 PM PST
In reply to: If

Thanks, thats what I wanted to know. All the best.

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PSU - my std. advice
by Willy / February 13, 2006 10:29 PM PST

First of all, "quality" matters, cheap is cheap. Get a namebrand psu of at least 400W+ or better. If you buy a generic brand then get the highest wattage you can find to produce the most stable psu from any poor quality or just cheap make-up. Namebrand psus tend to be stable for even less wattage than generic ones. Having a high wattage psu will have its power demands available for the "needed on demand" usage as any excess will be available as required. Read the specs as any psu should detail themselves via thier decal/sticker. Understand, wattage output of the rated wattage is avilable but not for constant output, its only for "peak" usage and can't be sustained for extended periods will surely test the "quality" of any psu, thus more rated wattage is a plus. Find the rated wattage, and expect at least 75% be available on a constant stable output. Last, remember all devices are attached to the power output should a psu fail, the strong possibility exists that it may take with it any/all weak devices to include the mtrbd. so keep that in mind.

tada -----Willy Happy

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Named brands?
by mr_tinka / February 13, 2006 11:02 PM PST
In reply to: PSU - my std. advice

Cheers Willy. How will I know a good brand from a not so good brand? Can you recommend some good brands please. I've been looking at a brand called Q-Tec. Are they any good?

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Some good ones
by Willy / February 14, 2006 4:56 AM PST
In reply to: Named brands?

Unfortunely there are so many brands, more than ever it can be pretty much a hassle. I recommend Antec,Enermax, Vantec, and I believe Fortec or fortac. The most trusted and reliable brand is PCPower&Cooling(very $) but darn good check thier website of same name.

tada -----Willy Happy

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