Suggestion for a Graphic Card

Specs:
Core i5 2500 (non-K),
DH67BL motherboard,
4x4=8GB Corsair 1333Mhz RAM,
Seasonic SII12 520W PSU 80+ bronze,
1TB Hitachi HDD,
LG DVD Writer,
3 Coolermaster + 1 NZXT 120mm Case Fans,
NZXT Gamma Case,
LG 23 inch 1080p LED Monitor.

Q/ I have seen a lot of benchmarks. I have seen people suggest 650 or greater watt PSU suggested for single card setups. Why is this so. I mean even a GTX580 can run very well on a 500 watt supply with room to spare (with no overclocking). What i mean is with 28nm cards, is it necessary for me to buy a higher wattage power supply if i want to use a GTX 680. As per benchmarks & my experience 520W is more than enough.

are you asking if your PSU will be able to handle a GTX 680?

for reference cards it is sufficient with your setup .

even if you OC the GTX 680 the PSU will handle it nicely with the rig you have ;-)

*img.hexus.net/v2/cpu/intel/Ivy/3770K/graph-17.png

*hexus.net/tech/reviews/cpu/37989-intel-core-i7-3770k-22nm-ivy-bridge/?page=13

*i.neoseeker.com/a/Nvidia_GTX_680/Power%20Use.png

^^ with a Intel 2600K @ 4.4Ghz

In our labs we could increase the GTX 680's GPU Clock offset by 171MHz, giving us a 1282MHz Boost. This did require the power target be increased to 132% though, because if it went any lower the Boost Clock speed decreased. Still, we were extremely pleased with the overclocking results as the Boost Clock increased by 224MHz over the target Boost Clock, which is nearly an 18% increase. However, since the Boost Clock on our GTX 680 was running at 1110MHz when set at default it is more like achieving a 172MHz increase.

The memory also overclocked substantially, which was surprising considering it is already clocked at 6000MHz effective. Our end results netted us an additional 285MHz. At this speed, the memory bandwidth was increased to 210.6GB/s.

*www.neoseeker.com/Articles/Hardware/Reviews/Nvidia_GTX_680/5.html