Power Requirements

[Titan2k]

I'm in the process of designing a computer for myself but before I get a PSU I need to know how much wattage is required.

1) Is there an easy way of determining peak power requirements? So many of the spec sheets I see online don't list them.

2) Is the PSU Calculator accurate in your opinion? I plugged in my current spec ideas and it gave me 408 W. Is there any margin of error included? I realize total power isn't quite as important as voltage and amperage per rail.

Any tips on power calculation and PSU selection are much appreciated.

 

[lobbyone]

IMO, I wouldn't trust that calculator entirely. Just get a 520w Corsair for peace of mind. :thumbsup:

 

[Oyeve]

Originally posted by: lobbyone
IMO, I wouldn't trust that calculator entirely. Just get a 520w Corsair for peace of mind. :thumbsup:

I agree. According to that calc, 2 psus ago, and with my current system and all the exras not listed, it said I need like an 800w psu. I had been using a 650w psu just fine. I did get a 750w PCP&C PSU a little while ago because I had added even more stuff and needed an extra PSU for another system so I figured id get the 750w for my main rig and use the 650 for the second rig.

 

[bob4432]

what are you planning on building? to be perfectly honest, a decent 500W unit will cover for just about any dual core single gpu setup, and actually probably more. if you go quad or multi-gpu you may want, although not necessarily need a 600W+ unit. talking about brands like enhance, seasonic, pc&p, enermax, not the 500W ones you get in a $40 case...

you can see my rig in sig - i added 2 additoinal ide 7.2k hdds, 5x80mm and 1x92mm fans and all is fine even @ 2.5GHz (stock V), so hopefully that will give you some idea. and my rigs are very stable - at least 12hrs orthos and memtest stable and can game as long as needed - they just run

 

[Extelleron]

When it comes to PSU requirements, don't listen to the hype that you need an 800W PSU to run your system. There are those who need that kind of power but unless you're running a crazy system, you won't. If you're running a dual-core system (AMD or Intel... with the exception of the Pentium D), 2GB of RAM, a single-video card, and one or two hard drives, you should be fine with a 450W to 500W PSU. Right now I'm running an Opteron 144 @ 2.4GHz, 2GB of RAM, 8800GTS, and one hard drive on an FSP 450W PSU without any problems.

The real thing that matters is the quality of the unit and the amps on the 12V rail. Wattage has its place but you don't buy a PSU just because it has high wattage without doing research. I'd take an FSP 450W over some Brand-X 700W PSU any day. Make sure you have enough amps on the 12V rail. If you're going to run a card like an 8800/X1900/X1950 you're going to need something over 30A (combined).

Tell us what your system will be like and we can give you a good recomendation.

 

[Titan2k]

That does actually help. It still would be nice to have a nice precise systematic method of determining power consumption. The previous two posts shot any trust I might have had in the power calculator.

This is what the current iteration of my rig looks like:Case: Nexus Breeze or Antec NSK2400
CPU: Intel Core 2 Duo E6600
Mobo: Gigabyte GA-965P-S3 (not positive on this one, depends on which case I choose)
Video: GeForce 8800 GTS 680MB with Thermalright radiator and fan
RAM: 2 to 3 GB DDR2 (undetermined brand or speed)
HD: WD Caviar SE16, 500 GB
Optical Drive: Samsung SH-S183L
Primary OS: OpenSuSE or Kubuntu with Beryl
Secondary OS: Windows XP or Windows Vista
Other: 5 in 1 card reader
Other: TV Tuner (an upgrade down the road)
IR: Generic serial receiver
DVR Software: Myth TV and LIRC

I'll probably just stick with the built-in network card and audio on the mobo. If I get the Nexus Breeze case it comes with a good quiet 500 W PSU. If I go with the other case I was considering going with a Seasonic PSU.

 

[conlan]

Originally posted by: Titan2k
That does actually help. It still would be nice to have a nice precise systematic method of determining power consumption. The previous two posts shot any trust I might have had in the power calculator.

This is what the current iteration of my rig looks like:
Case: Nexus Breeze or Antec NSK2400
CPU: Intel Core 2 Duo E6600
Mobo: Gigabyte GA-965P-S3 (not positive on this one, depends on which case I choose)
Video: GeForce 8800 GTS 680MB with Thermalright radiator and fan
RAM: 2 to 3 GB DDR2 (undetermined brand or speed)
HD: WD Caviar SE16, 500 GB
Optical Drive: DVD RW DL
Primary OS: OpenSuSE or Kubuntu with Beryl
Secondary OS: Windows XP or Windows Vista
Other: 5 in 1 card reader
IR: Generic serial receiver
Ohter: TV Tuner (an upgrade down the road)

I'll probably just stick with the built-in network card and audio on the mobo. If I get the Nexus Breeze case it comes with a good quiet 500 W PSU. If I go with the other case I was considering going with a Seasonic PSU.

The aforementioned Corsair 520W would run that just fine, actually any quality 450W+ PSU would run that fine, quality meaning Corsair, Enhance, FSP, Seasonic etc. etc.
I'm also running an FSP 450W on our Primary system: FX55, X1950XT, Raptor 74, Maxtor 250, SoundBlaster Audigy2 ZS, Intel Pro1000 NIC, 2X1 PC-3200 etc. etc, w/out so much as a hiccup.

 

[Titan2k]

Awesome, thanks for all the advice. I'm pretty confident about my total wattage now.