PSU calculators: are they reliable?

Extreme psu calculator is in the ballpark, good indicator and i've got the lifetime pro sub so it gives a decent average for the rail amperage needed as well, does come in handy when speccing a system. Maybe it will have the 670 when updated.
 
Thanks for the quick reply. I've factored in a bit of room for error so I shouldn't have to worry about getting a PSU that isn't powerful enough but to be honest I haven't bothered researching rail amperage. Is it something I should be concerned about considering my choice of PSU's is between a Corsair AX650 and an AX750?
 
lol not all, not with a single card. Don't know the power draw of that gpu but am reasonably confident that either psu will do 2 of them with ease in most rigs.
 
Justintime said:
lol not all, not with a single card. Don't know the power draw of that gpu but am reasonably confident that either psu will do 2 of them with ease in most rigs.
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Like I said I've factored in room for error (in the basic version of the extreme calculator). I used an 680 as a stand-in GPU, a higher overclock than I actually plan on doing, 100% cpu utilization, 100% system TDP, extra high performance fans, regular HDD's instead of green drives and 25% capacitor ageing. All that and I get a recommendation of 697W. Considering that's under a load that I'll more than likely never encounter and Corsair are said to under rate their PSU's I think I should be safe with the 650W.

This tends to happen when I'm about to build a new system or buy something expensive. I make my mind up then agonise and second guess myself for weeks on end until I realise I was right in the first place. So, thanks for putting my mind at ease Justintime.
 
No worries mate, good luck! One thing, the green drives, bit meh on those... they run about 5C or so cooler on avg. and aren't that much quieter and don't draw a significantly less amount then a decent 7200rpm one. I'd rather not trade off in the speed department for a minor drop in temp and noise.
 
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Only one of the two HDD's will be a green drive (the other's a WD Black), a 3TB Western Digital that will be purely for storage and backing up my Mom's laptop. I'll be using an SSD for my boot drive... hopefully an Intel 520 if they drop the price soon.
 
The samsung 830 256gb is currently a great value. I've used tons of SSDs and can't say that i've experienced any issues with Samsung, the Intels, while great in the reliability department were always a little overpriced imo.
 
Reliability is key for me. I'm prepared to pay a premium if it means greater reliability. Mind you, some of the SSD price drops and offers in the last week have really made me think. I've still got a couple of weeks before I order everything though, so I've got time to think it over.
 
Weirdly second hand is likely to be more reliable than new. Electronics (actually most engineered products) are more likely to fail when new than they are a few months in. Link.

Aside from that, overclocking hurts reliability and so does overheating. The overheating issue is an argument against especially small, m-itx systems. How reliable does the machine really need to be though? Crashing during a game is annoying, crashing a week into a CFD simulation is infuriating.

For PSU- single rail is usually better than multiple rail. Some devices are markedly better built than others, specifics are difficult to offer though. I'm a solid fan of PC power and cooling, Corsair are popular on here. A review site I quite like is Jonny guru. Spec'ing too high a wattage will waste money, but does mean the power supply is barely ticking over and unlikely to abruptly give up on you.
 
Not convinced. It's hardly unique to PC P&C either. The 20A limit per rail is specified in the interests of safety, but reading through the reasoning behind it I'm unconvinced. I've had a fair few shocks off mine (took the casing off) without causing myself or the psu harm, so the 60A limit on mine doesn't seem to be dangerous.

The usual way to build a PSU is as a single rail with a range of fuses/current limiters to bring each "rail" down to the atx spec- I don't see the point. Two entirely independent 40A 12V rails could be better than one 80A 12V rail if for thermal / electrical isolation reasons, but one 80A rail limited to 20A down four different wires? I'd rather have all the current available on any wire.

edit: but in fairness, I haven't read those forums- only electronics books on switching power supplies (trying to work out if I should make one).
 
I have a Zalman fan controller which measures the psu power and mine only just creeps over 300W under full load on Prime95. The Extreme psu calculator has my setup at 400W, recommending a 450W PSU. I'm currently building a new pc which the Zalman was bought for so will see how the accuracy between the measured power and the calculator is once it's built.
 
Gibbo_GTI said:
I have a Zalman fan controller which measures the psu power and mine only just creeps over 300W under full load on Prime95. The Extreme psu calculator has my setup at 400W, recommending a 450W PSU. I'm currently building a new pc which the Zalman was bought for so will see how the accuracy between the measured power and the calculator is once it's built.
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Treat those 'power meters' as gimmicks to be honest. However, prime95 alone is not a 'full load' did you run furmark on your gpu to get that pulling amps and did you load up your hdds and Dvds etc.. see where i'm going with this?
 
Not run Furmark, I will when I build the new pc as I've taken the Zalman off my current pc. Whilst playing MW3 it never went over 220W!! I bought it for the fan controller element and the cool (IMO) display.
 
JonJ678 said:
but one 80A rail limited to 20A down four different wires? I'd rather have all the current available on any wire..
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Simple reason is size of one wire need to handle 80A... and consider the fire hazard/damage to things before tripping an 80A fuse vs 20A wire on 20A fuse.
 
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