Question PSU analysis paralysis

sammykhalifa

Member
Dec 26, 2014
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Finishing up the part picking for my first new build in a long time. Almost there, but I drive myself crazy over powersupplies.

i7 13700k
2*32 DDR5
6600xt (had to buy when cards were pretty expensive, might upgrade eventually but it's fine for my purposes for now.)

Online power supply calculators tell me anything between 500-750w from various sources. 500 sounds wrong to me. Might go ~650 or so for a little headroom, if people think that's correct.

My current PSU is a pretty good Seasonic, but it's been running since 2014 so I think this could be a good time to update.

What is the feeling about older PSUs--new in-box but older models? Assumjing they were good units when they came out , are there any great advances that might obsolete them? I know about ATx 3.0 but I'm assuming that's for very high end graphics cards for the forseeable future.

. . . you know, typing this out I'm not even sure what my specific question is. Maybe just some guidance on whether I'm heading in the right direction or not. I've been indecisively scrolling through pictures of black metal boxes all afternoon. :D
 

BoomerD

No Lifer
Feb 26, 2006
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With all the discussion about transient power spikes recently, even though 500 watts MIGHT be more than enough for your current needs, personally, if you upgrade, I'd go with 700 or 750 watts...or more. It might cost a bit more to purchase, but won't cost you any more to run.

I just built an i5-13600K rig (see signature) and put a 750 watt PSU in the system.

 
Last edited:

mindless1

Diamond Member
Aug 11, 2001
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I keep using PSU till they fail, but if you want a longer service life for your new parts, I'd get something in the sweet spot of 700W-750W like BoomerD suggested, as it gives some margin but you don't really need more margin than that, and price per watt tends to rise above about that 750W threshold.
 
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kschendel

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Aug 1, 2018
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The 6600XT isn't known as a power spike monster. Maybe brief 200w peaks; along with the 13700K, I'm pretty sure you would be fine with a good 550w unit. If you want some headroom, 650w is plenty. Beyond that, it depends on what plans you might have for future GPU upgrades.

As for using NiB older units, as long as they were good units to start with, no reason to worry. (I might be careful powering up a unit that has sat idle for 5+ years, just in case some electrolytics decide to give it up; if it survives the first minute or so, it should be fine.) Is your old unit a Seasonic G? nothing wrong with getting a couple more years out of it, also nothing wrong with replacing it now. Whichever feels better to you.
 
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sammykhalifa

Member
Dec 26, 2014
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Thinking about it, I'm probably going to keep my current PC basically intact (minus the video card) for now so I'll get a new PSU. Thanks for the advice and suggestions everyone.