The 770 doesn't require anywhere near 44a to run. And having 2 rails just adds more protection from current spikes. The SeaSonic above is plenty capable of running a 770. To require a minimum of 44a means your system will draw a minimum of 528w. At full load, his entire system is looking around 325w MAX.
Yes but on split rails. You can't rely on split rails for a single card.
You need a high output single rail for a card like that.
I'm an electronics engineer- if the voltage on one rail is every so slightly higher than the other, all the current will be drawn from that rail overloading it. Then the rail drops so the other rail supplies all the load- which causes it to drop out.
Split rails are fine for SLI set ups where each card fits within the current capacity of 1 rail but combining 2 for a high power card is very unreliable at best. I don't mind Seasonic as a brand- however that particular model isn't great for such a high performance card.
Am a newbie in this things and this is my first build(pre building a already built pc 😀) so is the psu good or no? if it isn't similar to the system what psu should i get? budged 85-90$
A 'rail' isn't a physical thing you draw current 'from', it's what the OCP circuit monitors. The 620GB supplies one PCIe connector that runs 'from' the +12v1 rail and another 'from' the +12v2 rail. This PSU supplies plenty of power for a 770, which itself isn't even a very high-draw card.
The 770 doesn't require anywhere near 44a to run. And having 2 rails just adds more protection from current spikes. The SeaSonic above is plenty capable of running a 770. To require a minimum of 44a means your system will draw a minimum of 528w. At full load, his entire system is looking around 325w MAX.
This is why you need more than you're assuming (I know this is for a different card but the principal is the same)...
Look at the power consumption graph for that card. The peak power draw is 429w dispite the average only being 262.
A single rail at 24A gives 288w. Given the 770 can draw the best part of 200W *on average* it is quite capable of spiking above 288W.
When you have 2 rails, the voltages aren't going to be identical so you can't rely on the current being perfectly balanced between the 2. Don't get me wrong, that 770 should work with that supply but it quite possible it would have a tendency to randomly crash or freeze up for no good reason. The higher current single supply would be a more reliable solution and I'm sure it's possible to get one within Denis's budget so why go for a split rail supply?
Like I said earlier, half the power draw (roughly) is divided into each rail. Even assuming the ratio isn't exactly half, it won't be pulling 288w over a single rail, even with the CPU. 4-5+ years ago, multi-rail solutions weren't a good idea for a single GPU, but that issue has largely been taken care of (especially with the higher-end manufacturers)
And just to point out, the 290x is one of the most power hungry cards ever, so I wouldn't take its results and relate that to a GTX 770 lol