PSU.Suitable output

I'll probably be ordering my new PSU this week. I was going to get the largest Corsair unit 1000w which has great specs and gets good reviews but it is more power then I will need.

I recall reading something about it not being so good for the PSU to run underloaded all the time but not sure if I'm remembering it correctly.

So apart from the obvious $$ saving is there any other reason to not go for a higher powered PSU then you'll need?

All the (corsair) PSU's in my list are 80 plus silver rated but the 750 and 850 watt units have a 7yr warranty as opposed to a five yr for the 1000 watt unit.

There is $60 difference in price between the 850 and the 1000 and $100 between the 750 and the 1000. All are modular units. HX series.

The question of which hardware configuration you will be running needs to be answered before a size PSU can be given.

Which processor?
Which graphics card and how many?
How many memory modules?

and so on....

Here is a power supply calculator found at Newegg.com
http://educations.newegg.com/tool/psucalc/index.html

I know my requirements will be safely below needing a 1000w unit. 750 or 850 would suffice. just wondering if I were to get the 1000 unit does it do it any harm to never be worked very hard. It's just something I seem to recall reading somewhere but maybe I got it wrong.

However to answer your query either an i5 or i7 processor 4-8 gig of DDR3 memory. Single video card HD5770. 3xHDD

I think I can safely say that whoever made the claim about under worked PSU, didn't know what they were saying. If this were to be an issue, I believe you would see specifications along the lines of Minimum Power Requirements as well as the Maximum.

I think you're going way overboard here. Even high-end gaming rigs with two video cards in SLI or Crossfire usually need no more than 750 watts with two hard drives, 8 GB of RAM, etc.

Use the PSU calculators available at several websites. Newegg is a good start that Cliff gave you. The reason to use at least two calculators is to get a better idea of what you truly need. Plug in all the info and see what comes up. Then take that number and add a 20% cushion factor and you'll be good.

I am running three internal hard drives, a DVD-R/RW burner, 6GB of RAM, an ATI HD 3850 card, a wireless PCI card, 4 fans total, a high-end Gigabyte motherboard and an Intel E8400 3.0 GHz Core 2 Duo Dual core CPU.

My PSU is 550 watts and have plenty of room to spare!

Get a the correct sized PSU for what you have planned. Be sure it's rated at least as an 80 PLUS Bronze Certified unit.

I run a 550W with my single 5770. Now I know you like the velocorapters and I don't know if they require extra power but you will still probably be fine at 550, you definitely don't need more than 750 ... even for most dual GPUs that's enough.

My existing PSU is also around 550w and doing fine but it's getting a bit long in the tooth now. I want a modular unit and the smallest is 650w, there's only about $50 difference between that and the 750w and if I got the 750w , well there's only $40 difference between that and the 850w. Soo,,, plus I like the idea of a 7 yr. warranty. They are all 80 Plus Silver grade.

I run 6 case fans and in addition to the hardware I've mentioned I'll have DVD & bly-ray drives and in internal video card. Want a bit of headroom in case something comes up later in terms of chips.

Maybe what I read was that a PSU is most efficient when run at about 60% of it's rated output.

My 550watt unit is a modular but that's here in the States.

Get the 750 watt and you'll be fine. Even if you were stress testing your CPU and GPU at the same time you'd probably wouldn't go over 400 watts max.

But if you want to spend the extra bucks and so forth then go for it. On the other hand you could get the correct sized PSU and send the extra bucks you were gonna spend to the following new charity which I just established.

"The Nibiru2012 Society of the Everlasting Evangelical Assembly of Stargate Followers"

Then I could get that new Amazon Kindle I want!

hmm, if Iwas a noble soul but I'm not.. I'm more for the "help Mychael spend his money on hardware addiction group" heheh

Sounds like a malignant case of upgradeitis to me! Easy to diagnose, hard to cure.