620W enough power for SLI?

Jaffar

Jaffar

Jaffar

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Hi, do you think an Antec 620W High Current Gamer PSU would be able to power a i5 2500k 2 x GTX 560 SLI set-up?

I recently built a computer with one GTX 560, and was hoping I coud add in another without upgrading the PSU.

I've done some google searches and come across conflicting opinions. Some say a minimum 750W power supply would be required, whilst others report this kind of set-up uses <500w http://www.hardwareheaven.com/reviews/1104/pg18/asus-geforce-gtx-560-ti-directcu-ii-top-review-and-sli-performance-overclocking-power-noise-temps.html)

What are people's opinions on this?

P.S. By the way, a big thank you to everyone who provided helpful advice and suggestions for my first build, I am very pleased with the result :)
 
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I wouldn't risk it on a 620 watt PSU as even if its theoretically possible, the PSU would have an amazingly short life due to being maxed out constantly with games etc. I'd stick with the 750w min personally
 
I had an i7-970 with 2 GTX 460s, with a corsir 650w power supply, the ps fan would get quite noisey at full load (folding) Other rig with same spec had a Bequiet 850w and was relatively quiet.
 
Hmmm, I've also found this review of an overclocked i5 2500K (4.7GHz) with 2 overclocked GTX 560 TIs: [edit: seems I'm not allowed to include this link]

This system only has a 650W psu, and they record a 406W power draw under load. If this is accurate, would ~400W really limit the life of a decent 620W psu?
 
I was looking at what they pulled under stress - 449W for the entire system which is a older i7 socket1366 system that use more power than Sandybridge.
 
LOL, people !
Power draw doesn't mean wattage of required PSU ! It's good to remember for the end of life: ours, or ours components :)

450W power draw means we need PSU which can deploy more energy, part of which would be wasted. It is called PSU efficiency. Let's say PSU has got efficiency level of 80% - it means 20% of power is to be *wasted* as warm. So 450W "becomes" as 560W. Next, would you like your PSU to be completely dead after 2-3 years ? I don't think so... capacitors aging means wattage drop after some time, so to be insured to get the same power level, add next 10% and 560W "becomes" as 610W. Do you plan overclocking ? Add next wattage then.. and now you know, how "450W power draw" became as 700W PSU to buy.
 
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biuro74 said:
LOL, people !
Power draw doesn't mean wattage of required PSU ! It's good to remember for the end of life: ours, or ours components :)

450W power draw means we need PSU which can deploy more energy, part of which would be wasted. It is called PSU efficiency. Let's say PSU has got efficiency level of 80% - it means 20% of power is to be *wasted* as warm. So 450W "becomes" as 560W. Next, would you like your PSU to be completely dead after 2-3 years ? I don't think so... capacitors aging means wattage drop after some time, so to be insured to get the same power level, add next 10% and 560W "becomes" as 610W. Do you plan overclocking ? Add next wattage then.. and now you know, how "450W power draw" became as 700W PSU to buy.
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Try getting it the right way round.

The Guru3D figure of 450W is measured at the wall socket.

If the PSU was 80% efficient it would be drawing 450W and outputting 360W.
 
Surveyor said:
Try getting it the right way round.

The Guru3D figure of 450W is measured at the wall socket.

If the PSU was 80% efficient it would be drawing 450W and outputting 360W.
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Good shout;) Theres good amps on that Antec PSU too, and you could knock more watts off that 450w from the wall figure as you need less vcore etc for Sandybridge over a Core i7 965 @ 3750 MHz
 
LOL, when I measured my o'c-ed quad Q8400 @3.6 and two o'c-ed GTSes 250 in SLI it was over 500W power draw (from the wall) in stress. It seems the world starts to get proper direction then ;-)
Anyways, 620W might be enough for beginning, but "total combined power", capacitors and others (like 5x 120 fans) sooner or later would kill this PSU. Recommended 700W as minimum is quite reasonable for problemless working in the future.
 
Having a bit more than you need is always good for future proofing your system. Especially with PSU's
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Although it looks like many people would panic if their power draw started to come anywhere near the PSU's stated voltage. So you'd have to buy a new PSU with future upgrades anyway (unless you originally bought a 1000w beast just for 'insurance'.
 
OK, I'm considering whether it would be worth swapping my Antec 620W for something beefier. Does anyone have any experience of these PSU's:

http://www.overclockers.co.uk/showproduct.php?prodid=CA-202-CM&groupid=701&catid=123&subcat=
http://www.overclockers.co.uk/showproduct.php?prodid=CA-004-XF&groupid=701&catid=123&subcat=

Would these be more suitable for future SLI?

I'm sure Stulid and Surveyor know what they're talking about, but there doesn't seem to be any consensus on what PSU is needed. (I don't really want to have to fork out for another PSU by the time I go SLI in maybe 6-12 months).
 
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