Originally posted by: Demoth
Seeing how a lot of gamers use cheap Dells or the like or are like me and stuck with the cheap 450 watt no name PSU that came with a $45 case and delivers only 18A on the 12V rail.
1) Dell and a couple other OEMs use better quality per watt PSU than you buy from, oh Enermax or Antec. There's a big difference in retail marketed PSUs and OEM. OEMs aren't fooled by fake ratings and will not buy fradulently rated PSu, so when you see a wattage, you can't compare it to a retail psu targeted at end users.
2) There's no point in thinking wattage on an no-name-came-with-case PSU, nor amperage. It may as well not be labeled.
My friend actually got 2 7800 GTxs to run in SLI in a case like mine stable with no issues. I seriously doubt a X1900XT or a 7900GT will run stable in my system, but will be trying it first in a few months and only upgrading the PSU if I must.
It's not wattage that counts, nor even quality in the short term. It's rail distribution, % of system load vs % of transformer allocation per rail. In the longer term, it's failure as well and/or damage to other components. It serves no useful purpose to know what would work today with a 7800 card, because this is aiming towards a scenario (essentially trying to cause) system failure. It is no evidence a PSU can run a system to do it for a few months. It is not a part like a light bulb that is meant to be unscrewed several times during the ownership of a house, it is meant to last the life of the system.
Do you see where I"m going here? It is not the target to loop some game without crashing, the target is to have the system work for years. It is a well known, guaranteed failure to run a PSU hard. It also stresses other parts. If a part fails before the PSu that caused that, does, will you blame the correct part?
I always try to get the most performance out of the least amount of money despite any risks. Getting good FPS out of a $400 self built system and overclocking to the hilt is more satisfying to me then spending lots of money for the highest tier gear.
This is the common mistake made too often. Why would you think the choice is either low-end junk, or "highest tier gear"? Absolutely not either option, the goal is a reasonable quality unit with appropriate parts quality and amperage, the middle road. You're thinking like "my car must be either a Yugo or a Ferrari".
There are a few key places a PSU typically fails: Caps, fans, diodes, Fets, BJTs. Using a so-called 500W generic PSU one may have all the former parts inferior to what OEMs used 10 years ago in 150W PSU. Fancy heatsinks and colored fans are not the parts that make a PSu last. In any component the failure mode has to be considered and these weakest links addresssed. Simply throwing a larger transformer in (which is necessary but...) and upping the switching frequency can't help the weak links.
In short, it is reckless to spend hundred$ on a CPU, video card, motherboard, and not even manage to allocate $60 for a PSu unless system reliability is not important, as with a gaming-only system.