diff b/w modular & nonmod psu and multi 12v question

[athenaesword]

hey guys just wanna clarify some questions i have about psus.

1) what's the difference between modular and nonmodular psus? i've read that it's something to do with the cables being fixed or somethign but i'm not getting a very clear picture. also issit justifyable for the extra costs i'm seeing?

2) what's the point of a multi 12V rail? in what scenario would i need multi 12V rails? like are they better for multi gfx cards or would they benefit a single gfx card as well?

3) to get the current through the 12V rails, issit accurate to simply use the 12V max wattage/ 12V? im' asking this cus there's a list i'm refering to that doesn't specify current but has 12V max wattage. or do i have to divide the max wattage by 2 so i get the value for each rail? my physics tells me it's the latter, but just wanted to be sure. and this brings back to the question about multi rails benefitting a single card.

thanks!

 

[ausch30]

1) With modular PSU's most of the cables can be disconnected which allows you to only use the cables you need. The problem with this type of connection is it's increased resistance and it's not as secure a connection as the cables being hardwired. This is a hotly debated topic and there are many on both sides of the issue, I prefer the security of my cables being permanantly connected and I don't have a problem tucking away the cables I don't use.

2) There is a disagreement between manufacturers as to the need for multiple rails but I've found that the biggest reason they use more than one is that it allows them to use cheaper components due to the fact that there is less current flowing through them. I beleive it is better to have one high current, high quality rail rather than several lesser performing rails but others may disagree.

3) When using multiple rails the total amps are less than the sum of the rails. Take for instance my PSU the Thermatake Toughpower 750 which has 4 12v rails rated at 18a each but my total for the 12v rails is 60a. All PSU's should list the total current for each rail as well as all rails combined and if the one your looking at doesn't I would look somewhere else.

I realize I suggested a single rail PSU and I myself am not using one but mine is still a quality unit and I got a great deal on it. All things being equal I would choose the single over the multiple rail unit.

 

[athenaesword]

awesome explanation AUsch30 thanks. quick too, if i might add.

does anyone else have anything to chime in regarding the multiple rails?

is there a way i can calculate the total current? since that seems to be the number that i should be concerned with here, as i gather from your explanation that it is the total current that matters and not the amt of current/ rail.

 

[smokedyou911]

You can use this to find out about how many watts you need.
http://www.extreme.outervision.com/psucalculatorlite.jsp

As AUsch30 said a single 12v rail is better than multiple 12v rails, but good brand psu's with multiple 12v rails are still good.

 

[athenaesword]

You can use this to find out about how many watts you need.
http://www.extreme.outervision.com/psucalculatorlite.jsp

As AUsch30 said a single 12v rail is better than multiple 12v rails, but good brand psu's with multiple 12v rails are still good.

hi, look's like a very useful calculator =] i got 366W. would that be the output power or input wattage without taking into account efficiency yet?

 

[Zorg]

hi, look's like a very useful calculator =] i got 366W. would that be the output power or input wattage without taking into account efficiency yet?

No, That's recommended PSU size. Here is some information for you to read and a good price on a top quality PSU.
Power Supply Myths Exposed!
Silencer® 610 EPS12V Power Supply