PSU +12v rails

[kimouk]

Hi,My power supply just exploded , it's normal cauz i m using a gtx 460 with a bad power supply. i m going to buy a new psu but i never understand the 12v rail thing, most of the psu here have 2 +12v rail and each of them doesnt have the amps that the gtx 460 need ((24 amps ) like 1 psu got 12v1 with 18 amps and an other +12v2 18 amps ,there is no psu with a single rail in my country and i never understand these rails , most of ppl say you calculate them like this 18+18=36 amps but i think it's wrong since it's 2 seperated rails .

 

Plz reply only if u are sure of ur answer not guessing and ty  ^__^

 

 

[quan289]

Rails are like breakers of circuit box inside of your house. Most multi-rails PSUs comes from a single rail source then is split by multiple of OCP (Over Current Protection). Each 12v rail monitor it own set of cables, and if a device that is plugged into to that set of cable exceed the OCP limit that had been set, the PSU will shut off.

 

While I did say that most PSUs come from a single 12v source, you are right. You can NOT add the individual rails together, because as stated that's the limit set for a group of wires, not the entire 12v output capacity which is usually lower than what you added up.

 

Anyways, the 460 can be power on a single 18A rail by itself. It just a matter of how the manufacturer implemented those rails, which is usually isn't a problem as most proper modern day PSU will set up the cables in a way that you don't trip the OCP.

 

If you need a recommendation, it would be helpful if you can provide a link to where you are able to buy from, as well as your budget in your own currency.

[kimouk]

Ty quan for your reply, however i disagree with wht u said about a gtx 460 can run with 18A rail cauz i tested it and it wasnt runing well,to make my question more clear if a psu has 2 pci-e rail (6 pin) are they taking the amps from the same 12v rail or each pci-e rail has its own 12v rail , cauz the gtx 460 need 2 pci-e rails 

i didint find any links that got a good psu on it also my budget isnt that much like 100$ but i ll post here when i find a good psu

 

thank you again for your help

[quan289]

Ty quan for your reply, however i disagree with wht u said about a gtx 460 can run with 18A rail cauz i tested it and it wasnt runing well,

 

Let say your 12v combine is 30A or 360w.

 

http://www.techpowerup.com/reviews/Zotac/GeForce_GTX_460_1_GB/29.html

 

Max power draw during furmark (unrealistic scenario during actual real world usage) is under 170w or 14.17A. So in most cases, you are drawing <14A at stock on a 30A 12v rail by itself. You just want to make sure the the power draw doesn't exceed the rated 18A (generally, the actual OCP limit is usually set higher what it is rated).

 

So like I had said, by itself, it should not have any problems, provided that it had been implemented properly. Older failed PSU had it set up of in a way that one 12v rail supply power to both the GPU and the CPU rather than putting them on two separate rails. So on a PSU with 18A, they may run into problems with shut down, despite the overall capacity is more than enough. But again, manufacturer have gotten better at this and now is setting it in a way that it generally shouldn't be a problem on a quality modern unit.

 

I'm not sure what PSU you have tested it on, but let me say this. Not all PSU are build the same.

Also, you never had mentioned your other computer components.

 

to make my question more clear if a psu has 2 pci-e rail (6 pin) are they taking the amps from the same 12v rail or each pci-e rail has its own 12v rail , cauz the gtx 460 need 2 pci-e rails 

i didint find any links that got a good psu on it also my budget isnt that much like 100$ but i ll post here when i find a good psu

 

thank you again for your help

 

What country are you from?

[Psychatog]

This one: http://us.ncix.com/products/?usaffiliateid=1000031504&sku=89067&vpn=100-B1-0600-KR&manufacture=eVGA&promoid=1313

is more than powerful enough. 49A on a single 12V rail.

[Scottonpc]

I would recommend a PSU from BeQuiet. Top quality and quiet (obviously).http://www.bequiet.com/en/powersupply

[kimouk]

Thanks you guyz for your awsome help

 

@quan289 i m from tunisia and i think i just found the psu that might be good OCZ ZS 550 watts

http://www.sbsinformatique.com/Onglet2-prod-3234-BLOC-DALIMENTATION-OCZ-ZS---550-WATTS.html#onglets

 

@Psychatog it seems an awsome psu i wish i could find it in stores

 

@Scottonpc It seems a nice psu too but the same problem those arent avaible here ^^

[Psychatog]

Thanks you guyz for your awsome help

 

@quan289 i m from tunisia and i think i just found the psu that might be good OCZ ZS 550 watts

http://www.sbsinformatique.com/Onglet2-prod-3234-BLOC-DALIMENTATION-OCZ-ZS---550-WATTS.html#onglets

 

@Psychatog it seems an awsome psu i wish i could find it in stores

 

@Scottonpc It seems a nice psu too but the same problem those arent avaible here ^^

You do NOT want to buy from retail stores, but online rather.  Which country are you buying from?

[kimouk]

@Psychatog i m from tunisia and i never tryed to buy things online and if they can sent it to me + taxes will be high i guess ,but if it works i might try it if there is a trustable link to buy from

[quan289]

Thanks you guyz for your awsome help

 

@quan289 i m from tunisia and i think i just found the psu that might be good OCZ ZS 550 watts

http://www.sbsinformatique.com/Onglet2-prod-3234-BLOC-DALIMENTATION-OCZ-ZS---550-WATTS.html#onglets

 

Yeah, that's a good unit for your system. I'd recommend it.

[Psychatog]

@Psychatog i m from tunisia and i never tryed to buy things online and if they can sent it to me + taxes will be high i guess ,but if it works i might try it if there is a trustable link to buy from

I don't know what retailers are out there sadly.

[kimouk]

@quan289 Okey ty i think i m going with that one

e

[kimouk]

@Psychatog it's ok ty anyway , i think the OCZ ZS 550 watts isnt far from the one you posted