What power supply do I need for this...

[Bubbleawsome]

I will be running a i7 870 (tends to go over tdp to ~120w) with an overclocked 280x. My current wattage with my stock 7770 is 230w max. I *think* that my system will pull around 650w with the 280x at 1.3 vcore and as high as it will go. With power supply's ratings I am confused between a bronze 750, a gold 750 or something higher. It would be nice to be modular and a white color scheme is prefered. Budget comes first though.

 

[TemjinGold]

There is no possible way your single 280x will get to 650w.

 

[Bubbleawsome]

Overclocked 208x's commonly hit their 500w tdp wall. That and a 150w system and you have 650w. With efficiency it gets complicated. I think a gold 750 will do it.

 

[lehtv]

Overclocked 208x's commonly hit their 500w tdp wall. That and a 150w system and you have 650w. With efficiency it gets complicated. I think a gold 750 will do it.

First off, the TDP of a 280X is officially 250W.

Secondly, it is not physically possible for a 280X to draw 500W from the wall. A card with 2x 8-pin PCIe connectors can theoretically draw a maximum of 375W (150W per plug, 75W via the motherboard). Instead of 2x 8-pin, a 280X typically uses one 8-pin connector (max. 150W) combined with a 6-pin connector (max. 75W), limiting the maximum to 300W. While reaching such a power draw would require massive overvolting, it would also require the PSU to be extremely inefficient (only 60%) for the load at the wall to be 500W.

Finally, 500W would be abnormally high even if it was the wattage for the whole system. Let's look at the more power hungry 290X, for instance. In Guru3D's full GPU load testing, an overclocked system with a custom cooled 290X sucked 400W at the wall, that's roughly 350W of load on the PSU.

 

[Bubbleawsome]

First off, the TDP of a 280X is officially 250W.

Secondly, it is not physically possible for a 280X to draw 500W from the wall. A card with 2x 8-pin PCIe connectors can theoretically draw a maximum of 375W (150W per plug, 75W via the motherboard). Instead of 2x 8-pin, a 280X typically uses one 8-pin connector (max. 150W) combined with a 6-pin connector (max. 75W), limiting the maximum to 300W. While reaching such a power draw would require massive overvolting, it would still require the PSU to be extremely inefficient (only 60%) for the load at the wall to be 500W.

Finally, 500W would be abnormally high even if it was the wattage for the whole system. Let's look at the more power hungry 290X, for instance. In Guru3D's full GPU load testing, an overclocked system with a custom cooled 290X sucked 400W at the wall, that's roughly 350W of load on the PSU.

You're correct. The 513w was the entire system. Durp
But still, would my bronze 550w handle it?

 

[Torn Mind]

I ran a 7970, which is practically the same as a 280X, on an Antec Neo Eco 520C with an Xeon W3520. The PSU was the old version with 40A on the 12v rail, not the new one. Even with Powertune set to +20, there is no way it will overload a 550 W PSU. No way.

 

[nwo]

You'd have to do some heavy OCing on the CPU and GPU in order to come even close to 500W system consumption. As already stated, 280x has a 250W TDP, add up 120W for your OCed CPU, and you're not even at 400W. Which means you will have nearly 200W left over for the rest of your components.

 

[Bubbleawsome]

Ok, thanks!

 

[Bubbleawsome]

Question; if the rig is showing 502w from the wall does that mean that the actual load is closer to 450w? And does that mean that 550w at the wall is max load for the PSU (460w with efficiency) or ~650w at the wall? (550 with efficiency)
I'm wondering because the HIVE series wasn't known for being the best and I can't afford for it to take anything with it. I can afford a new corsair 750w though.

 

[thedosbox]

Question; if the rig is showing 502w from the wall does that mean that the actual load is closer to 450w? And does that mean that 550w at the wall is max load for the PSU (460w with efficiency) or ~650w at the wall? (550 with efficiency)
I'm wondering because the HIVE series wasn't known for being the best and I can't afford for it to take anything with it. I can afford a new corsair 750w though.

PSU capacity is measured on the output side, not the input.

 

[Bubbleawsome]

So 616w from the wall is max load? Thanks!

 

[SViscusi]

So 616w from the wall is max load? Thanks!

I assume you're using something like a kill-a-watt in which case that's going to measure draw from the wall not what you're internal components are actually usings, so if you're seeing a ~500w load, then depending on the efficiency of you're psu, your components will be using ~400w.

In short, you're current psu is fine. If you have the money and want to upgrade, go right ahead, but you don't need to right now if you don't want to.

 

[thedosbox]

So 616w from the wall is max load? Thanks!

If your system only needs 400W, then a 550W PSU is going to be plenty (with the usual caveats about 12V capacity, connectors, construction quality etc).

 

[Bubbleawsome]

I assume you're using something like a kill-a-watt in which case that's going to measure draw from the wall not what you're internal components are actually usings, so if you're seeing a ~500w load, then depending on the efficiency of you're psu, your components will be using ~400w.

In short, you're current psu is fine. If you have the money and want to upgrade, go right ahead, but you don't need to right now if you don't want to.

If your system only needs 400W, then a 550W PSU is going to be plenty (with the usual caveats about 12V capacity, connectors, construction quality etc).

Now I'm confused again. Should I judge the PSU's maximum capacity by what I see at the wall, or the wall with efficiency? So is it showing 550 at the wall (from the kill-a-watt) mean that it is maxed out? Or is it delivering 550 and showing higher at the wall maxed out?
I expect my system to draw close to 450w, so the 550w psu will be fine, but I want to know for future purchases.

 

[Torn Mind]

Now I'm confused again. Should I judge the PSU's maximum capacity by what I see at the wall, or the wall with efficiency? So is it showing 550 at the wall (from the kill-a-watt) mean that it is maxed out? Or is it delivering 550 and showing higher at the wall maxed out?
I expect my system to draw close to 450w, so the 550w psu will be fine, but I want to know for future purchases.

You PSU's maximum capacity is determined by the rated DC voltage and amperage; or at the outputs of the connectors, so to speak. The wattage reading you measure at the wall includes both the electrical energy that goes through the PSU to the motherboard and the electrical energy that gets converted into heat energy along the way.

To approximate the DC power consumption, you simply multiply the wall wattage by the efficiency percentage, which various according to load, such as 500*.85=425W. The remaining energy is dissipated as heat, with 75 Joules of heat energy dissipated per second.

 

[Bubbleawsome]

Ok, I got it as well as I ever will.

 

[TemjinGold]

550w PSU means it can MAKE 550w (for your PC). Because of efficiency, it will TAKE more than 550w from the wall to MAKE 550w. Does that clear it up?

 

[Bubbleawsome]

550w PSU means it can MAKE 550w (for your PC). Because of efficiency, it will TAKE more than 550w from the wall to MAKE 550w. Does that clear it up?

Yep. I feel stupid now. At least I know for future reference.

 

[Torn Mind]

Well, energy can neither be created or destroyed, only converted but the term "make" gives a intuitive sense to the process. Basically, electricity flowing through the pathway either stays as electricity(electrons flowing) or it gets converted into another form of energy, such as heat etc. Something that is 100% efficient will have no energy converted into another form of energy along the way.

 

[TemjinGold]

I don't think he needed to get anything that technical. Just something simple to understand.

 

[DigDog]

http://www.nzxt.com/product/detail/132-HALE82-v2-700w-power-supply.html

you are welcome

 

[Bubbleawsome]

http://www.nzxt.com/product/detail/132-HALE82-v2-700w-power-supply.html

you are welcome

Aw man, I just decided that I wont buy one and you show me this nice, clean, 700w PSU that fits my black and white theme? :awe: I was going to go HALE series, but I think that $99 might go better served towards a few case fans to keep my 280x cool.

 

[DigDog]

johnnyguru reviewed these and found them to be quite decent (which means excellent in humanspeek).

remember if you manage to keep the power draw between 40% and 60% of the PSU rating you will get better efficiency too.

Also they have other hale models. And they don't cost too much.

(i dont work for nzxt; my psu of choice is a EVGA, but just sayin')

 

[Bubbleawsome]

Lol, this thread turned out to be rather pointless. I am going to buy a 7870 instead. It is over $150 less and will still max almost anything at my 1280x1024. I learned how PSU's are rated though! Thanks guys!