500w? You're kidding right
No. Not at all.
My system could pull almost 600w @ max using the latest
http://extreme.outervision.com/psucalculatorlite.jsp (i'm VERY realistic/truthfull when using the calc) and nearly 650w
Yet another bogus calculator which ridiculously oversizes everything.
According to that POS my system as it stands supposedly draws ~570W and it's recommending me a 620W PSU minimum.
Words cannot describe what BS that is.
with just 10% capacitor aging, which was confirmed by system crashing/instability prior to my PSU upgrade
Your mainboard most likely has solid polymer capacitors. Capacitor aging is a non-issue in general, unless they're talking about the PSU caps, in which case the polymer caps on the board and everywhere else would eat up the little bit more ripple old (5+ years) PSU caps would "let through". If the PSU has crappy capacitors which have failed, that won't help though and would in the and still cause instability or weird glitchy-ness. In that case though, the PSU is simply defective, not underrated.
I was running a 3yr/4yr old 700w unit.
Most likely a junker with bogus labels if it wasn't able to power your system properly. Or it had crappy/bad caps, causing insane ripple (noise in the power), in turn causing instability.
I have a bit more in my case than just a CPU/GFX card (which consume ~400w themselve's) so 500w would be cutting it REAL close and the PSU would definately not last long!
A HD5870 is rated at 188W max. Unless the "V2" in your specs means you're running two cards in crossfire, or you OC'ed the card, that value doesnt change much. Assume 200W if you're REALLY cautious or running a mild/stock OC.
The Q9550 has a rated TDP of 95W, with the absolute max. power dissipation being 132W.
If you're OCing it, let's say a somwhat unrealistic value 180W, which is almost double the TDP.
For the sake of argument, I'm gonna say 190W GPU, 180W OCed CPU. That's a total of 370W of load on 12V. A good ~500W PSU will have the majority of oomph on the 12V rail.
The pretty ancient/outdated Seasonic S12-II 520W for example has a combined rating of 480W on the 12V rails alone (see attached pic). You'd be 110W away from that limit with this setup. This isn't including other stuff like HDDs, ODDs etc. though, but even then you'd still have headroom not to blow shit up. Under full load (CPU + GPU) with OC that is.
I find most people grossly under estimate their component's to try and "save" a few $$ on the PSU.
Quite the opposite. Most people grossly
overestimate the component power consumption, just like you do. Gospel posts like yours in various forums then spread the misinformation all over the place. Nothing personal against you, just for the records.
The system in my specs thing on the left has been working fine with the Seasonic S12-II 430W since mid-2009. Graphics cards changed quite a bit over time though. 8800GTS (G80, 152W), temporarily (4months) a 8800 Ultra (175W), a GTX260 (the older 192SP version, 182W) and now a HD6870 (151W). The rest of the system has been pretty much identical, apart from a few HDD swaps and going from DDR2 to DDR3.
The PSU never complained, and like I said before I still have room to spare. I once temporarily stuck a customers HD5750 into it to see how far I could push it. Granted, it was only running in a modified PCIe x1 slot (open end) so that wasn't really the greatest idea, but those extra 86W didn't cause any havoc either while stresstesting (which was quite a challenge by itself).
So either my theory is correct, or my PSU is somehow underrated by one heck of a lot (as in: capable of far far more than 430W), which I pretty much doubt
When sizing a PSU i try to get something with 100w - 150w more than what i need, i find it is the "sweet spot".
Generally a good idea, if you weren't relying on those bogus PSU calculators, which already add a (sometimes quite massive) headroom to each and every component. See my result above. 570W power consumption with a 620W PSU being recommended? lol
Like i said i have never had a PSU issue/failure and i have always used OCZ unit's so i suggest them
Nothing wrong with that, but it's no wonder you didn't have any problems with a PSU at a bit more than half load at the worst. It won't die from being bored to death.. It'll just have horrible efficiency.
No intent to buy a new one, at least not for my own rig. I have to order PSUs all the time for customer boxes though
PS: that Seasonic S12-II 430 (the older non-Bronze version sadly) cost me 50eur back in 2009 when I built the system, which with the current conversion is roughly 66usd.
edit: this post ended up being quite a lot longer than I expected
edit2: I seem to have a tendency to try and close quotes with [/url] somehow
