PSU Power GTX 670 SLI

TheTacticsGuy

Hey guys,
I'm looking to upgrade my PC fairly soon and was wondering about the wattage of my current PSU (650W).

I want to:

overclock my i5-3570K to about 4.2 GHz
Add another GTX 670 in SLI
Add another HDD
2 new fans
2 sticks of 4GB RAM

What is a comfortable wattage in order to do this?

BloodBath

Have you got a link to the same psu to see the specs. Wattage isn't the only limiting factor. You might be ok but 650 is on the edge for that.

TheTacticsGuy

Super-Flower Amazon 80Plus 650W

http://www.hardwareversand.de/articledetail.jsp?aid=24479&agid=1629

spix

A good quality 550w psu is plenty for that assuming it has 4 pci connectors.

A single 670 plus 3570k overclocked only uses around 250w. Add another 150w for the second card and you get 400w. Power supplies are most efficient at 50-80 percent usage so anything in the 500-800w is ideal.

What is the model of your psu? As long as its a true 650w psu (around 50A on the 12v) then you'll be fine.

TheTacticsGuy wrote: »

Super-Flower Amazon 80Plus 650W

http://www.hardwareversand.de/articledetail.jsp?aid=24479&agid=1629

Yeah that will work fine, no need to ugprade.

TheTacticsGuy

spix wrote: »

A good quality 550w psu is plenty for that assuming it has 4 pci connectors.

A single 670 plus 3570k overclocked only uses around 250w. Add another 150w for the second card and you get 400w. Power supplies are most efficient at 50-80 percent usage so anything in the 500-800w is ideal.

What is the model of your psu? As long as its a true 650w psu (around 50A on the 12v) then you'll be fine.




Yeah that will work fine, no need to ugprade.

Ok great, its just that my research online suggests a 750W minimum

Gumbi

TheTacticsGuy wrote: »

Ok great, its just that my research online suggests a 750W minimum

According to whom, and where? It depends on the quality of the PSU in question.

spix

TheTacticsGuy wrote: »

Ok great, its just that my research online suggests a 750W minimum

You'd only need 750w with a much more power hungry cpu and tons of hard drives/extra peripherals. It also accounts for lower quality psu's.

The main thing to look for is how many pci-e cables come with your psu. If it has the proper amount without needing adapters then 99.99 precent of the time there won't be a problem.

TheTacticsGuy

spix wrote: »

You'd only need 750w with a much more power hungry cpu and tons of hard drives/extra peripherals. It also accounts for lower quality psu's.

The main thing to look for is how many pci-e cables come with your psu. If it has the proper amount without needing adapters then 99.99 precent of the time there won't be a problem.

Cheers dude

BloodBath

An overclocked 3570k will use around 150w alone depending on the clock speed. Maybe only 110w-120w or so with a 4.2 overclock. The 670's will easily chew up 150w each at stock speeds. Over 200w overclocked.

You should be in the clear then. Plenty of amps on those super flowers. Nearly 500w of the psu is dedicated to the 12v rails.

spix

BloodBath wrote: »

An overclocked 3570k will use around 150w alone depending on the clock speed. Maybe only 110w-120w or so with a 4.2 overclock. The 670's will easily chew up 150w each at stock speeds. Over 200w overclocked.

You should be in the clear then. Plenty of amps on those super flowers. Nearly 500w of the psu is dedicated to the 12v rails.

It should definitely be lower than that. Uses under 100w @ 4.8ghz with 1.33v fully loaded as seen here.



A 670 overclocked to its max will add around 30w, I think thats what mine added if I recall correctly. With a 2500k and 670 is was 220w from the wall at stock speed (with 90 percent efficiency its really only 200w) With an average oc on the cpu and 670 to its max, power usage playing bf3 went up to 270ish (+50w)

BloodBath

How accurate is that program? I wasn't aware of any ways of measuring cpu power consumption as there are no sensors or cables that can be monitored to get those figures.

Does that take the igp into account?

I'm assuming it's making calculations based on your speed, voltage and processor rather than taking any readings. It doesn't make sense that a 40% overclock would only result in 23% more power consumption.

I've seen overclocked 670's pushing 215w and higher.

-edit- Nice overclock by the way. What cooler are you using?

spix

BloodBath wrote: »

How accurate is that program? I wasn't aware of any ways of measuring cpu power consumption as there are no sensors or cables that can be monitored to get those figures.

Does that take the igp into account?

I'm assuming it's making calculations based on your speed, voltage and processor rather than taking any readings. It doesn't make sense that a 40% overclock would only result in 23% more power consumption.

I've seen overclocked 670's pushing 215w and higher.

It's pretty accurate. Just tested it

i3 2120 w/ 7770 idle power usage 43w. Coretemp reporting 6watts by the cpu. Ran prime95 small fft and coretemp now reports 38w. Power meter reading 77w.

Difference between idle less 6 and cpu fully loaded = 40w so its off by 2.

Using the blend option on prime95 increases power usage to 81watts but drops to 36 on coretemp, presumably as it stresses the ram more.

No idea how it reads it but seems pretty legit and not based on calculation of speed/voltage.

BloodBath wrote: »

-edit- Nice overclock by the way. What cooler are you using?

Not my pic, just one grabbed off google. This is mine though



Overclocked, undervolted and watercooled! Load temp of 36 degrees.