What PSU Wattage should I use for my specs?

[pharmit_singh]

I'm currently using an HX1000 which is probably overkill but I want to know what's the best wattage should I use for my specs? If it matters, I use all of the ports of my gpu. Thanks.

OS : Windows 7 Ultimate x64
CPU: i7 4790K 4.0GHz
COOLER: Cooler Master V8 GTS
SSD: Intel SSD 730 Series
HDD: 2x WD Black 6TB & WD Green 1TB
MB : Asus Maximus Formula VII
GPU: ASUS ROG Matrix GTX 780 Ti 3GD5
RAM: Corsair Vengeance 4X4 DDR3 1600MHz (16gb)
PSU: Corsair HX1000

 

[4745454b]

You probably use less than 400W. GPUs can swing a bit and I'm not looking up the exact specs for that model. But "up to" 400W should be a close guess. This means at idle or surfing you are using ~10% of your PSU, and while gaming only ~40% of your PSU. So yes, very much overkill. The HX series is a good quality series however and I wouldn't go through the hassle of replacing it.

 

[pharmit_singh]

You probably use less than 400W. GPUs can swing a bit and I'm not looking up the exact specs for that model. But "up to" 400W should be a close guess. This means at idle or surfing you are using ~10% of your PSU, and while gaming only ~40% of your PSU. So yes, very much overkill. The HX series is a good quality series however and I wouldn't go through the hassle of replacing it.

So which wattage and model should I go with?

 

[4745454b]

You already have an HX1000. Why change it? It's massively overkill, but as I said it's not worth the hassle of changing it. The HX series is great and can provide high efficiency over a wide range of loads. It might be a bit worse than it should be at the idle/surfing end, but I wouldn't spend hundreds of dollars just to get 2% more efficency.

 

[pharmit_singh]

You already have an HX1000. Why change it? It's massively overkill, but as I said it's not worth the hassle of changing it. The HX series is great and can provide high efficiency over a wide range of loads. It might be a bit worse than it should be at the idle/surfing end, but I wouldn't spend hundreds of dollars just to get 2% more efficency.

I'm not going to change it. I just want to know what wattage is balanced for my specs and which series of corsair's psu?

 

[4745454b]

Why would it matter?

It depends on how much you want to load your PSU. Some people say you shouldn't load a PSU to anything over 50%. So a 400W system would need an 800W PSU. Those are an "odd duck", so you'd probably pick something from the 750W-850W range. I'm willing to load a PSU to a higher percentage, around 80%. (The difference in efficiency between 50% and 80% is usually around 1-2%.) Doing the math means you need a 500W PSU. I personally would get a high quality 550W. For the record my current system I've estimated to draw around 300-325W. I'm using a 450W PSU to power it. If you are getting a lower end bronze unit I'd drop the % load down to 50-60%. The older bronze units can't handle longer term 80%+ load.

 

[Karadjgne]

A 780ti is 600w recommended. That said, there really aren't any worthy 600w units, and you are looking at the potential to OC with that build, so a good 650w would be best, a mediocre 750w at worst case.

As said, you'll be pushing @400-600w after OC if the system was maxed out, which is almost a physical impossibility to run everything at 100% load simultaneously, and recommended psu limits are a broad range due to psu quality being so broad, you could easily use a good quality 550w unit if the OC was kept mediocre.

 

[pharmit_singh]

Why would it matter?

It depends on how much you want to load your PSU. Some people say you shouldn't load a PSU to anything over 50%. So a 400W system would need an 800W PSU. Those are an "odd duck", so you'd probably pick something from the 750W-850W range. I'm willing to load a PSU to a higher percentage, around 80%. (The difference in efficiency between 50% and 80% is usually around 1-2%.) Doing the math means you need a 500W PSU. I personally would get a high quality 550W. For the record my current system I've estimated to draw around 300-325W. I'm using a 450W PSU to power it. If you are getting a lower end bronze unit I'd drop the % load down to 50-60%. The older bronze units can't handle longer term 80%+ load.

Sorry I'm just ignorant with psu's. I din't know about the psu efficiency and the load that matters. So in the future should I get the HX750 or the RM650x? I'm still learning about PC stuff so pardon me thanks.

 

[Karadjgne]

In the future, neither. By the time that HX you own finally ups and quits working on you, the 780ti will be in the same shape, if not dead before the pc dies. That HX you own is one of the best psu's ever built, very high quality and very high longevity expectancy. It should easily last 10+ years regardless of warranty. By that time, your gpu will be so outdated and behind in power necessity, you'll be looking at replacing it regardless, and even it's closest competitor, the gtx1070, will run all day long on a good 550w psu after OC.

 

[4745454b]

I think he means when he needs to buy a new PSU. It's hard to say. Most GPUs, even the high end ones, are in the 200-250 range. There are a few that can hit 300W+, but they aren't normal cards. If you assume an OC'd high end card can hit 300W, and an OC'd CPU can use around 150W, most systems will use at most 500W. It is possible for a system to use more, but you'd really have to buy some oddball parts to get there. In this case if you were buying to cover any single GPU system, getting a 650-750W PSU would be the way to go. I would argue most gaming systems don't even cross 350W load, so planning for 500W is a bit odd. A better thing to do is worry what size to go with when your PSU finally dies. Who knows what landscape will look like then.

 

[Karadjgne]

Exactly. My point being that op has such a good psu, it shouldn't have any issues outlasting 2x usable pc lifetimes. By that time, it's plausible that even high end gpus would have no issues on a 450w psu, the 4790k being no better than a i7-2600k is now and could stand replacing etc. It's pretty wild, it's easy to recommend a replacement psu for a piece of junk, as relates to needs now, but op would be hard pressed to find any reason to replace his current psu, it's that good, and large enough to cover any pc from high end, sli, even full custom loop. OP couldn't have bought a better psu without serious effort looking.

 

[4745454b]

It is WAY more than he needed, but as we've said there isn't any real point in replacing it now. Use it, buy something more appropriate later when needed.