I'm not saying it's not possible for an Ultra to damage anything, but is highly unlikely. Those were very good units for that day and age, very stable and lots of 12V power (not something you took for granted in 2003/04), but the design is more than 13 years old and you cannot compare this to newer post Pentium 4 era PSUs with active PFC and other stuff..I still use my aaaanncient Antec TruePower Trio 550w. In 20+ years I have never seen an Antec psu go bad (nor any from Corsair, Fortron, PCP&P, or Seasonic ftm), so I can't help but feel loyal. The 'mid' level brands like Thermaltake and Cooler Master, well.. Just plan on buying a 650-700w if you really need a 500-550w, and make sure the 12v rail setup is pretty strong if you plan on running many case accessories.
I have to advise to NEVER use an offbrand or gimmicky (led's, windows, other useless garbage) psu, the consequences can be disastrous. I had an Ultra X-Connect (shiny, chromed, one of the first modular psu's) that seemed like a great buy at the time, until it fried my motherboard. Wouldn't have been so bad if they had at least honored their meager 2 yr 'lifetime' warranty...
Old rule of thumb for psu's... Just go to a computer store like Fry's, that's big enough to have multiple psu's on display, and weigh each one in hand -- the higher quality psu's use beefier components and heatsinks, which drastically increases the weight. It'll show you one fact of life, that outside of a few special deals, you always get exactly what you pay for.
The very reason I took a chance.. was very pricey in those days finding a PSU with a strong 12v rail, let alone multiple rails. Combined with modular cables, seemed like such a great deal! I was a very early adopter, first generation.. After a slew of burnt up PSU complaints on their support forum, they upped their warranty and changed the oem they got their components from, but did nothing for existing owners. Mine was just under a year old, and they refused warranty coverage because they felt they were justified with just a retail recall. Again, hence my warning to avoid anything too gimmicky or new. I have boxes of this crap -- force feedback headphones, non-CL sound cards, other niche devices. Remember the Kyro..? DxI'm not saying it's not possible for an Ultra to damage anything, but is highly unlikely. Those were very good units for that day and age, very stable and lots of 12V power (not something you took for granted in 2003/04), but the design is more than 13 years old and you cannot compare this to newer post Pentium 4 era PSUs with active PFC and other stuff..
It's childs play these days.Back then when you were inserting lots of RAM IC's into sockets it was very easy to slip up with one and I should know, I did it on more than one occasion.Building computers should be easy but somehow isn't.
Why is two rails bad idea on crossfire with quality 1k watt PSU? You can have each on different rail and it's plenty of power for those cards. Even still, two rails are most probably only for safety reason (an actual one rail design with two fuses) and I bet you can drive both cards on single rail if all other system components are on the second one...Corsair 850HX one rail.
I had Corsair 1000HX but it was dual rail and with 2 R9 290x it was a bad idea.