graphically midrange system spec question

[vinnie97]

Hi, I'm thinking of building a system (currently using a 4-year-old plus Athlon XP 1700+ overclocked to 2000+) with substantial processing power (audio encoding and eventual sequencing/production via software like Cubase being the main use as well as video encoding potentially not to mention plenty of multitasking!) but not top-of-the-line graphics (which seems to be the most power-intensive aspect in high-performance desktops currently). These are the parts I've dreamt up thus far (with particular emphasis on the power supply, of course ;)):

CPU: E6700 (perhaps overkill in my case)
Memory: Corsair TWIN2X2048-6400C4 2GB Kit DDR2-800 XMS2-6400 (I could probably get by with half this amount for a good while longer).
Mobo: MSI 975X Platinum V.2 975X P4/P4EE/Pentium D/Pentium XE/Celeron D 1066FSB LGA775 DDR2 ATX Motherboard w/Audio, Gigabit LAN, RAID/Serial ATA Retail (I need firewire for external sound...also gives me the possibility of doubling up video if I become an avid gamer :p ...though no possibility of quad-core CPU support, which is really further into the future than I care to look when price is weighed against performance gain initially).
Video: GIGABYTE GV-NX76G256D-RH Geforce 7600GS (this still provides decent gaming performance at lower resolutions on many recent games, right?)
HD: 2 x PATA, including Seagate Ultra ATA/100 7200 RPM/16MB Cache/400GB and Maxtor Ultra ATA/133 7200 RPM/8MB Cache/120GB drives (from current machine...with the possibility of upgrading to SATA in the future). I have to assume these will be my theoretical system's "achilles heel"/weakest link.
Optical: 2 x PATA (from current machine)
and most appropriate for this forum,
PSU: Enhance ENP-5246G 460W Pentium D/Athlon X2 Power Supply (http://enhanceusa.com/series.php?series_id=4#45) (a similar 400W model was reviewed by Jonny a few months back and with high ratings I might add ;)). Note: I just realized this device isn't 80plus-certified like the 400W reviewed. I may move up to the ENP-5150GH (http://enhanceusa.com/series.php?series_id=4#115) if the price is right and if it's deemed necessary. EDIT: Price is only $13 more at eWiz, shipping prices being the only caveat.
I suppose I'll be needing at least 2 x 120mm fans for the case as well (one for inflow and one for outflow).

I'm wondering if I'm skimping a bit too much with the PSU (the best price I can find is $64 after shipping anyway), especially since I've toyed with the idea of at least overclocking the machine to the speed of an X6800 (most likely not beyond, as I don't want to muck about with expensive cooling solutions). According to my calculations, I need about 25A (not including the firewall soundcard I'll be using) max power on the 12V rails. I don't know what the max amperage of the 12V rail on this PSU is but the lower-rated model was 28A according to Jonny's findings, so I would presume this unit could push at least 30? I guess emailing the manufacturer would help to remove all doubt.

Any thoughts from the pros on board here? Will the potential voltage increase required by overclocking to an x6800 (or even to 3 GHz) render the PSU useless?

[burebista]

Your system should be handled fine at stock speeds by a S-12 330.
ENP-5150GH is plenty. Maybe you should look after Silverstone Element Plus (same Enhance unit but silent like a rock).

LE: For what 25A?
CPU: TDP 65W (http://users.erols.com/chare/elec.htm) ~7A (assuming 80% Vcore circuitry efficiency)
GPU: 2.5A (http://www.xbitlabs.com/articles/video/display/power-noise_6.html) in full-load
HDD: 0.6A (http://www.silentpcreview.com/article657-page3.html) idle, 1A seek.
MB+MEM: 3-4A
Optical: ~same as HDD
PCI Cards: doesn't matter they draw from 3.3 and 5V mostly
With all your components in full-load (techically impossible) you have a ~18A from 12V.

So where are those 25A? :)

[vinnie97]

Thanks for the values and informative links! My calcs were off (they were done VERY roughly and not using the formulas). :D My absent mind needs a little direction so please bear with me...Would you mind explaining how you calculated the 7A from the TDP of 65W? I see the max. core amperage is 75A but how did you determine the 12V rail?

I found that Silverstone for about $90 from a reputable dealer, so I might splurge for it. I guess that's not too far from the $69 (including shipping) for the Enhance 5140GH (400W), especially when considering the benefits of future-proofing and (more) silence. I'm wondering if I could overclock to 3 GHz bus speed with even the 5140GH (12V can manage max of 28A). I guess a USB device like an MP3 player, flash drive, keyboard and the firewire soundcard would tap further into it, bringing it to 21A, still below the max. That doesn't leave much headroom for overclocking and especially adding PCI-e cards in the future, I'm sure.

[burebista]

Some time ago on our Seasonic reseller one of our best OC-er (Micutzu (http://www.xtremesystems.org/forums/member.php?u=240)) made a test with a S-12 330 and a Venice 3000+ @2.88GHz and a Connect3D X1900XTX (http://forum.computergames.ro/35536937-post36.html), or a Venice 3000+ @2.66GHz and one EVGA 7800GTX (http://forum.computergames.ro/35554722-post1.html) or even two 7800GTX SLI and the PSU was flawless.
Of course is not a setup for daily use, but a 500W PSU is more than enough for that extreme OC-ing.
Usually he use a Silverstone Zeus 650W for that kind of tests, but he was curious about S-12 330.