Simple question why buy an expensive psu?

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macker123

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Ok, I am an experienced PC user, been building systems for myself and friends for over 5 years and always simply buy the cheapest case with a 350w psu as everyone wants to save money.

I have never understood why people spend so much on power supplies when I can get a whole cheap case for $30. I do understand the more watts the more power. I also understand the better the power supply the cleaner the power, but honestly I have been using "cheap" psu's for 5 years in probably 30+ computers.

Perhaps the psu has been to blame for sporadic problems, perhaps it has been the cause of a couple of RMA's?

My simple question, other than watts, why do you need an expensive psu?

For example I am putting together a computer with the following, why shouldn't I simply stick in a cheap 350w psu?
3.4ghz HT 1mb Cache Intel
D915PBL Intel Mobo
36gb WD Raptor
160gig Maxtor
1gig DDR2 Ram
PCI Express Video Card - Not Decided Yet
DVD Burner
TV Tuner
Modem
Floppy

Believe I am not dumb, but at the same time just want a simple answer why. I am sure lots of people must be feeling the same as me.
 
macker123 said:
Ok, I am an experienced PC user, been building systems for myself and friends for over 5 years and always simply buy the cheapest case with a 350w psu as everyone wants to save money.

I have never understood why people spend so much on power supplies when I can get a whole cheap case for $30. I do understand the more watts the more power. I also understand the better the power supply the cleaner the power, but honestly I have been using "cheap" psu's for 5 years in probably 30+ computers.

Perhaps the psu has been to blame for sporadic problems, perhaps it has been the cause of a couple of RMA's?

My simple question, other than watts, why do you need an expensive psu?

For example I am putting together a computer with the following, why shouldn't I simply stick in a cheap 350w psu?
3.4ghz HT 1mb Cache Intel
D915PBL Intel Mobo
36gb WD Raptor
160gig Maxtor
1gig DDR2 Ram
PCI Express Video Card - Not Decided Yet
DVD Burner
TV Tuner
Modem
Floppy

Believe I am not dumb, but at the same time just want a simple answer why. I am sure lots of people must be feeling the same as me.
Click to expand...

All the answers to your questions have all been posted at the top of the forum.

From all the "Help Me" threads (not to mention the ones that bleed over into the AMD/Intel threads) in here it would seem not everyone has been as fortunate as you have been.

Beyond that, May the computer gods of luck remain with you in perpetuity.
 
because we don't want to take a chance with cheap PSUs, especially when some people are spending $500+ on the video card alone

also, because we want stable systems that we know can handle anything we throw at them

a quality PSU is a worthwile investment that should last you for several years
 
so ur chance of ur psu dieing and taking with it all ur parts is less likely to happen.
 
Okay so basically preventitive.

I mean I don't walk across a big field of grass in the city so I don't get stuck with a needle. Honestly the chances are slim to non, but why take the chance. Basically it is the same way with a PSU, if you forget about the watts?
 
I firmly believe that the price of the PSU should be proportional to the cost of the whole machine. Also your ability to pay for an entire new system is also a factor; if you're ok with absorbing that higher costs for a short term gain of a few hundred, then by all means be my guest.
I want a PSU that I can throw anything at and not even have it blink, I guess that's just the kind of stability freak I am... it's also why I have a server grade mobo with ECC RAM and a beefy UPS ;)
As was also mentioned, if you buy the right supply, it can be quite an investment for the future. I don't plan on buying a new supply for the next couple of years, barring a drastic change that I can't mod my way out of, which at this point seems quite unlikely.

You seem to brush off the idea of cleaner power. For something as key to the operation of every single component in your system, I woudl hope that you would take it into more consideration
 
ESD & Electromigration Rant

Electromigration In Depth <article refered to below
"so, both elevated temperature, and voltage, can cause voids to form in the circuits of any chip, a problem that becomes more and more important as the number of atoms that comprise the width of that circuit decrease, (that first link was written when the manufacturing scale was at 0.18 microns we are now at .09 microns (90nm) with some chips) in addition the clock rates that the power is cycled through is all that much higher as well, making the chips all that more suceptible to ESD, voltage irregularities and temperature"
Click to expand...

the price of progress

and "other than power consumption" becomes equally imporant when a modern config could easily have a CPU and GPU that alone eat 165 watts off the +12V rail

in 5 years the CPU power consumption has easily doubled even with the numerous strategies employed to make them more efficient, to the point that infrastructure has become a huge concern at the enterprise level, where computing density has outstripped the infrastructure capacity to both power and cool


Maximum Power Dissipation
(Coppermine \Tualatin in the article above)
PII-350.....21.5 Watts
PIII-500E..13.2 Watts
PIII-733B..19.1 Watts
PIII-933.....25 Watts
PIII-S-1.4...31.2 Watts
(Willamette\Northwood\Prescott)
Thermal Design Power Dissapation
P4-1.3G....48.9W
P4-2.0A....54.3W
P4-2.5G....61W
P4-3.0C......81.9W
P4-570J.......115W
source

it takes 9.8 amps of +12V to feed a P4 3.20E Prescott thats 117 watts right there
and youll find few 350 watt supplies geared towards the +12V rail as the primary power for the mobo
there has been a sea change in how we power the most hungry components from the +5V rail to the +12V rail

Power supplies become increasingly expensive
When I initially asked about this on a mailing list, Solaris x86 advocate Al Hopper told me I was drowning in my tea, and that it was "all very simple". I love the simplicity of Unix people.

He explained that the later P4 CPUs take their power from a 12 Volt feed and, using the onboard voltage regulators, generate the high current, low-voltages they need to operate (anywhere from ~ 1.6V to around 2.7V). So the first requirement is a PSU that has plenty of power available from the 12V supply. Since the older ATX compatible PSUs didn't supply much current from the 12V section you have to ensure that your new PS delivers enough current (or power in Watts) from the 12V section. That's why using your old P3 ATX PS is a big "no-no".

He then described the history of the post-P3 power supply mess:

The earlier Athlon motherboard manufacturers decided to solve the 12v problem by using an additional 4-pin square connector to get the extra 12V those CPUs required. However many older PSUs didn't provide the 12V 4-pin square connector.

The motherboard makers then wised up and decided that there was nothing magical about a square 4-pin connector, so they put a normal hard disk type socket on the motherboard and provided the 12v power via a standard hard disk (4-pin inline) connector. Problem solved - you may now use your older PSUs provided they supply sufficient 12V current (many did not).

Further confusion came from PSU manufacturers not specifying the capabilities of the PSU in a way that allowed the end user to verify it's 12V power output rating.

In the meantime the ATX spec was saying "use the new 6-pin" inline connector - and very few motherboard makers implemented it.

Just to be sure, some motherboard makers, implemented *both* the hard disk style 4-pin inline connector and the square 4-pin connector. They said "use either or both in any combination you like".

The spec then evolved to the 24-pin main connector. Again, most motherboard manufacturers did not wish to make their customers mad by mandating that they replace their power supplies. This might cause their customers to avoid motherboard upgrades. Some used a "special" 24-pin connector with the extra 4-pin connection blocked off, or colored so that the user could plugin a 20-pin plug into the correct end of the 24-pin socket on the motherboard. Many others simply ignored the 24-pin requirement in the specs. Again - problem solved - use your older PSU.
Click to expand...

only now with the adoption of PCI-E and higher end graphics cards and processors the hand has been forced, we are past the point where the older supplies will cut it, an era of confusion and misadventure has dawned :p
 
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