Trying to understand amp requirements with a multi rail psu

Toggle sidebar Toggle sidebar
cothoffee

cothoffee

Commendable
May 7, 2016
11
0
1,510
I was going to buy a gtx 970 and wanted to use my old psu, an antec ea 750w (http://) but I can't make sense of the amperage requirements. The 970 needs 28A from the 12v rail and the psu has four 12v output circuits at 25A.
DSCF1951.jpg


Does this mean the psu is insufficient or are the combined amps fine?
How do you calculate amps with 4 rails?

Thanks,

 
Solution
C
Hi Cothcoffee.
In general, you want to go to your users manual of the PSU and look for how much it can output in each rail, it should be your PSU max minus whatever is used elsewhere.
As far as I know, modern PSUs have a certain max amp amount that can be delivered if ALL rails are used, and a different (higher) amp amount if less rails are used.

However, In the past I have read of some PSUs that were deliberately designed so that a certain rail would have a fixed amount of amps going into it (I have always thought it to be fake).

http://www.antec.com/PSU/

Here you can read how Antec sees the situation.
Sort by date Sort by votes
cothoffee

cothoffee

Commendable
May 7, 2016
11
0
1,510


Hypothetically though, when would individual rail amps matter? Would it fail to work even if the requirements were accurate?
 
Upvote 0 Downvote
C

cats_Paw

Splendid
Oct 19, 2007
3,237
14
21,415
Hi Cothcoffee.
In general, you want to go to your users manual of the PSU and look for how much it can output in each rail, it should be your PSU max minus whatever is used elsewhere.
As far as I know, modern PSUs have a certain max amp amount that can be delivered if ALL rails are used, and a different (higher) amp amount if less rails are used.

However, In the past I have read of some PSUs that were deliberately designed so that a certain rail would have a fixed amount of amps going into it (I have always thought it to be fake).

http://www.antec.com/PSU/

Here you can read how Antec sees the situation.
 
Upvote 0 Downvote
Solution
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom