300W Power Supply V 400W Power Supply 1

[blondebier]

What is the difference between using a 300W and 400W power supply buiding computers these days?

And I don't mean 100W

Is there any advantage in using a more powerful supply?
Do you need to buy special motherboards for 400W, 500W and 600W supplies?

I've got a 400W P4 branded power supply and was just wandering whether it woul be ok to use with an MSI KT4V motherboard and a Athlon 2600XP chip?

Has it been made specially for Pentium motherboards and chips?

If a 300W supply will do then why are there lots of more powerful ones on the market?

Any comments would be most helpful.

Thanks,

Francis.

 

[Grenage]

Is there any advantage in using a more powerful supply?
Do you need to buy special motherboards for 400W, 500W and 600W supplies?

You won't need a special MB for them, there is no advantage other than the fact that you can run more devices.

I've got a 400W P4 branded power supply and was just wandering whether it would be ok to use with an MSI KT4V motherboard and a Athlon 2600XP chip?

You shouldn't have any problems using it no, but if it ain't broke....

Has it been made specially for Pentium motherboards and chips?

It will be Pentium rated, i.e tested and found to be good enough. This is no different that the old 300W that came out as "Athlon Rated".

If a 300W supply will do then why are there lots of more powerful ones on the market?

If you have a large amount of SCSI hard drives, CDROMs etc it may be required, usually you wont find a use for them in anything bar Servers.

 

[paparazi]

I don't agree with alot of what Grenade says I'm afraid.
The " if it ain't broke" philosophy don't wash with me I'm afraid, I've seen too many blown PSU's over the last year and none of them were broke before they actually broke!
Trouble is non of this would be an issue if it wasn't for the fact that when PSU's pop they often take out other precious hardware at the same time, I have seen power supplies take out CDroms, DVD's, CPU's, Hard drives and memory all in one foul swoop!
I look at it this way, a 400Watt PSU running at 70% full load is always going to be more reliable than a 300watter running flat out not to mention that voltage regulation becomes more irratic the closer you get to a PSU's maximum output thats why weak PSU's often cause random PC restarts.

When it says "P4 ready" it just means it has the extra power lead that P4's use and indeed some of the new Athlon boards are starting to use.
All new PSU's are P4 compliant, some even have the new serial power connectors, so if you intend to upgrade to serial ATA then this could be a deffinate plus when sellecting a new PSU, Athlon XP's are automatically covered!
I would say anything "high end" would benefit from the added stability of a bigger PSU.
Martin

Replying helps further our knowledge, without comment leaves us wondering.

 

[franklin97355]

<i>If a 300W supply will do then why are there lots of more powerful ones on the market?</i>

In the same vein, If you can get around town in a Ford why are there Land Rovers on the market?

 

[jfryer]

The wattage is not as important as the rated Amperes that each line (3.3V, 5V and 12V) delivers.

A 400W PSU is great, but if it only delivers 12A on the 12V line you are asking for trouble, a 300W PSU that can deliver 15-18A is a better bet (providing everything else is equal)

I run a Radeon 9700Pro (a VERY power hungry card), 2800+ Barton, 16xDVD, 52x24x52x CD-RW, 80Gig WD HD, internal modem, 1.44 FD and 2 case fans on a 300W PSU and it hasn't even hiccupped once.

My standard test of the PSU is to burn a CD from my DVD to the CD_RW at max speed, while formatting a 40Gig Partition on my HD while, and playing Morrowind. The system runs like a dead dog but it DOES test the abilities of the PSU to the max, and it always passes.

However if I tried that test with a 400W PSU with only 12A on the 12V line, it would fall over in a quivering mess.

The PSU I use is a Aopen model FSP300-60ATV.

The reason there are bigger power supplies out there are 2 fold
1) There are computers out there that need more power (SCSI servers, dual cpus machines etc) and to get a higher Amp rating you need more wattage. But doesn't account for the fact that some PSU that have a higher watt rating perform worse that a lower wattage PSU, which brings me to point 2
2) People are blinded by big numbers, a 400w PSU has a high number then a 300W PSU ergo it MUST be better (and in some cases it is, but not all), its a marketing tactic as much as anything (end cynic mode)

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There is no magic, only onions
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[G0AOZ]

Be aware that some of the bigger PSUs are manufactured for server applications and may have the bigger motherboard connector. I guess the one you're running with right now will be a standard 20-pin connector (2 lines of 10 pins). These bigger ones may be 24-pinners...


ROGER - G0AOZ.

 

[roderickom]

Amps

Roderick Shilling

http://www.orbitmicro.com

http://www.qubitmicro.com

 

[BernardStewart]

Paparazi is right.
I have a system with a 550 watt supply - and have had 2 blown over the last 2 years.
Generally go for a higher rated supply if you can - it will help if you want to expand the system later.
The other iisue you should bear in mind is power supply problems - these are more common than you think - so I have a Galatrek APU. The monitoring software shows considerable variations in voltage with surges, spikes and breaks - 99% of which you will not notice.
We have two power lines coming into the premises - something I did not know until I called out the Electricity Board. I showed them the monitoring graphs (they had never seen it before!!!.
As a result they switched me to the other supply and all is much quieter (not sure if the second is generally 'reserved' for special users, e.g. Doctors etc.

http://www.ipd.me.uk/