A power supply discussion (X-posted)

[richjob]

It is a subject I'm interested in so I want to know. (EDIT: THis started out as a question, but now will look at things to look at - ESPECIALLY FOR PEOPLE BUYING PARTS LOCALLY)

-Do you just use what is in the case?

* It really depends on the case and the system. If you buy a high-end Antec case, the onboard power supply unit will be better than what is sold with other cases. If you run an integrated board with no seperate video card, one HD, one stick of RAM, one optical drive, it may be sufficient.

Otherwise avoid.

Not only because the power supply units included with cheap cases ARE cheap and nasty, but they probably don't have enough 12V amps to power a good video card properly, they are probably not accurate in what they say they can do (yes, they lie at times), and the components are of a cheap quality.

Incidentally, unless you are a qualified electrician, NEVER try to fix a power supply. It carries quite a lot of current in the transformer that does not dissapate. Shock IYMC or worse. Again, personal experience.


Important: Good power supplies make your system and overclocks more stable and better. If you are of that.


-Do you buy a seperate power supply depending on your graphics card?

* That would be the best thing to do, yes. If you are paying upwards of US $200 or equivalent on a video card, why skimp on the power supply needed to push it?

-What do you look for in a power supply?

Reliable and nonfluctuating current, decent 12V ratings... Read up on JohnnyGURU and his websites and the forums he hangs out on. He tests a LOT of power supplies.  THE PSU FAQ on the Australia OC site has it nicely.

http://www.overclockers.com.au/wiki/PSU_Faq

(order of importance roughly is: PSU Brand, 12V rail capacity, needed connectors (24pin in particular), Group regulation or not (none preferred), then wattage)

-Do you hold to "a heavier power supply is better"?

Generally speaking, I used to, because it was a decent dirty guide. Not a hard and fast rule, but good enough for government work.

Now, no. The components that will determine how good a power supply is don't weigh a lot. What I will say (anecdotal here - just my observation) is that brand name power supplies always weigh more than the generics.



I've found these websites to be helpful.


http://www.overclockers.com.au/wiki/PSU

http://www.jonnyguru.com/

http://www.psuinquisitor.com

http://www.overclockers.com.au/wiki/PSU_Faq


Oh yeah. What power supply is in YOUR rig?

Mine? Depends on the PC.

I'm building a budget rig (not heavy 3D gaming - more "get myself back into light gaming - no Quake 4 or FEAR here" rig and it's gonna use the TT2 430 watt jobbie that sells in the Wizz. Not a lot of amps on the 12V, but it's not a highend system or video card, and should be fine.

I tend to buy a case and IMMEDIATELY jettison the power supply. If you need a 300-350 watt Codegen or Xtech, I usually have some lying around. Cluttering up my parts bin...

Even a TT2 430 watt power supply with not much on the rail (less than 20A) is better than the Codegen 500 watt or Viomax 500 watt you get bundled with some cases - or buy seperately.

[TriniXaeno]

some pretty meaty reading there.

One thing that always amazed me about powersupplies, is that the tiny shuttle PCs with mediocre 200-225 watt PSUs, would run monster specs and not fail.

You would expect them to go belly up.

But they didn't.

Only the most demanding of video cards would pose a problem (ATI All in Wonders) and even then, some people got those to work.

Amazing.

but yeah, the PSU has gained notoriety in recent times as a common point of failure in machines. Tons of cheap ones around and they blow frequently, taking components with them.

I understand why. It is a hard sell, to get someone to spend $500+ on a PSU. Only the hard core and over clockers would spring for that.

Leaving the vast majority of PCs out there running crappy PSUs. They will fail eventually like everything else. Just look at the thousands of DELL or Compaq PCs, check their powersupplies and have a good laugh.

Personally, I always look at the 12V rail rating first and then the wattage.

Give me 20a and up on the 12V rail and 450 watts or more and I'm happy.

[richjob]

The Shuttles may have had small PSes, but their rated was as stated, and their 12A rail was always up to spec.

The wattage wasn't a huge issue.

If you put your machine specs through a power calculator, it probably does 300-350 W MAXIMUM at full load.  Put in some wiggle room (25-40%) and you should be good.