400w + 500w gpus running on 550w psu

[nadeejalm]

I recently upgraded to gtx 970, but noticed frame rates are still unstable when playing AC Black Flag maxed out on 1080p resolution. Since GeForce Experience recommends to lower PhySx Particle to normal level I have decided to use my older gpu as my dedicated PhySx processor. Problem is my psu is 550w and 970 recommends a 500w psu while my older 550 ti recommends a 400w psu.
So what you guys think? Is it a good idea to connect my older gpu?
Here is my PSU;
FSP HEXA+550

 

[Suztera]

No. Not recommended. PSU too weak.

 

[Archaic59]

Your budget PSU has dual +12 volt rails @ 18 amps each. GTX 970 needs apprx. 28 amps at about 150 watts. You could do with a bigger, better PSU.

 

[Karadjgne]

For both cards you'd need a larger psu, its not unlike an sli setup. For either one alone, your psu currently is fine, even if a tad bit weak on the 12v output.
Most of your problems with AC:BF are with the game itself. Some games just aren't very well engined or optimized so tend to suffer restrictions at ultimate settings unless totally overpowered by a gpu/sli

 

[Deleted member 217926]

As a PhysX card the 550 Ti will never draw anywhere near max load but that FSP Hexa is a low end unit. In fact I wouldn't trust a GTX 970 to it. Here is a review of the 400w version of the same unit.

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story6&reid=341

I would probably put it in tier 4 in the list in my sig. Not quite bad enough to worry about system damage but pretty bad.

 

[Deleted member 217926]

Your budget PSU has dual +12 volt rails @ 18 amps each. GTX 970 needs apprx. 28 amps at about 150 watts. You could do with a bigger, better PSU.

That's not correct. It shows as having 4 x 12v rails at 18a each. Now that's not additive. It supplies a max of 456 watts on the 12v rail and since amps x volts = watts we can tell it can supply a maximum of 38 amps ( 456 / 12 = 38 ) on the 12v rail.

http://www.realhardtechx.com/index_archivos/FSP.htm

The unit is also not even 80 Plus certified.


Edit: And this is just what I was talking about in our PM earlier. So many different models! I'm wrong. That is a newer unit that is at least 80 Plus certified.

This unit supplies 432 watts on the 12v rail for 36 amps. So the 12v rails are additive. Sorry about that 😛

Found a picture of the sticker here:

http://www.goldfries.com/hardware-reviews/fsp-hexa-550w-80-plus-h2-550-power-supply-review/

Odd that they would make it weaker than the old model. I would still avoid it.

 

[nadeejalm]

Can you guys please recommend a good psu for my system if I'm to go with the dedicated PhySx processor setup?

 

[Deleted member 217926]

Use the tier list in my sig and stay with tier 2 and up. I would go with 650 watts just to be sure.

Or post a link to where you are buying from so we can find you the best deal.