Does PSU Capacity Affect Heat/Fan Necessity and Efficiency?

[nocona_xeon]

I'm building a HTPC and using the following generic components: mobo, dual core Intel CPU (65 watter it appears), X4500HD gfx (onboard the mobo), 8GB ram, 1 SSD (C-drive), 4 WD "green" HD's (16TB total for storage), a PCIe HD capture card (with its own H.264 encoding chip - I like it a lot), and that's about it. I cannot see adding any other items that would consume wattage. The onboard GFX chip works just fine for HD playback and if needed, an addon like FFmpeg could perform any "realtime video modifications" as necessary (sharpness, color, etc, ffmpeg has a ton of functionality - a great work of software).

My question has to do with what wattage capacity PSU I should purchase. The reason being is that I would very much like the PSU's fans to NOT turn on unless necessary. So, I am wondering if getting a beefy 800W PSU from a quality vendor when the system is only requiring around 300W would be a good idea?

Or, would that idea backfire on me and I would not end-up with a silent PSU and I would actually be more inefficient in using power (higher power bill, don't like that).

Kind of like Class A audio amplifiers. I believe that those, while excellent sounding, always drew a high amount of power no matter what the volume level was.

Thanks!

 

[Aretak]

Most semi-fanless PSUs activate their fan at a certain load percentage (around 40% usually), so yes, getting a higher-rated unit would mean you could load it more before the fan starts spinning.

 

[i7Baby]

You'd only need a 400W+ psu for that build.

But try a 'eco' type eg http://www.pccasegear.com/index.php?main_page=product_info&cPath=15_972&products_id=22691 - fanless.
But make sure you've got an airey case so the inside doesn't heat up too much..

Graphics wise you migh tbe better of with AMD eg A10 6800k - better graphics

http://www.hardwarezone.com.sg/feature-haswell-4th-gen-intel-hd-graphics-alls-well-new-igp/performance-and-conclusion-0

 

[nocona_xeon]

Thanks for the advice/help. I greatly appreciate it and was hoping for those answers. And I'll check out that A10 6800K that you mentioned. New to me but always looking for interesting items!

 

[i7Baby]

The psu I linked to is actually fanless.