What would you say? Re 850 Watt PSU

[Elf_Boy]

Last week my Ultra X4 PSU died a sudden horrible and quite smelly death.

Now pls read system specs below

I called around Reno to all the various computer stores. None of them stocked anything over 650 watts. The last store I called rather then accept I wasnt interested in a 650 watt PSU tried to lecture me that watts dont matter. The number of hard drives in my system dont matter and if I knew what I was talking about I would agree that it was all about how many amps the power supply could put out and I would be perfectly OK with the 650 watt PSU he had in stock.

I dont claim to be an expert, and sadly I ended up at Best Buy as the only place that did have an 850 in stock. I always check them last.

I know the [H] has members who know far more about the specifics on power supplies and
energy needs of systems then I. So, my question, would a 650 have been fine? Do watts not matter? Do hard drives/ram not matter? We're talking 4 HD + 1 Optical.

Looking at the Nvidia specs my GPU pulls up to 244 watts. My current CPU pulls 95, though I plan to put in a 125 or 145 watt cpu in the future. I have no idea what my ram, mobo and sound card pull.


On the good front, I called Ultra X4 today to do an RMA. Since they dont have any 850's in and likely wont get any for a few months they will be sending me a 1050 to replace it.

 

[Tsumi]

You would have been fine with a 500-550 watt power supply, even if you decided to upgrade to Bulldozer or Thuban, and overclock the hell out of them. The key thing is to make sure you have a good quality unit.

Hard drives add minimal power draw. Unless you're running like 20 of them, they're usually ignored. Same goes for optical drives.

RAM sticks also add minimal draw. Add-on cards are also fairly minimal.

 

[statikregimen]

650w would probably have been plenty, depending on the quality. Amperage is a very important metric, but Watts = amps * volts, so...I guess it just depends on how you look at it.

Ultimately, regardless of which metric you look at, continuous rating is more important than peak rating. You also have to consider how many 12v rails the PSU has. Most people will say a single rail is best (and I agree), but as long as each rail delivers sufficient amperage, multi-rail is ok... Typically (but not always), high-end, top-shelf manufacturers, like Corsair or Seasonic, will list the continuous wattage and will use a single rail design, while low-end generic brands usually will put peak wattage and have it divided among multiple rails. Again: that is by far not a rule, so you need to check the specs.

Hopefully I haven't muddied the waters more for you, but to reiterate: 650w would have been enough for a high quality unit (probably even generic, but it's the one thing that can not only kill itself, but take out other expensive hardware with it, so I don't skimp in this area), but an 850w very well may run more efficiently and last longer, if you're running it well below it's rated specifications, and also give you room to add hardware/upgrades to your system. Perhaps another GPU, additional hard drives, higher wattage CPU, etc.