Overkill Power supply disadvantage?

[mee_wanton]

Hi guys

I will be building an APU budget gaming rig based on the new A10 7870k. I'm possibly getting a graphics card in the future to upgrade the machine.

I put the fact that I might get a graphics card into consideration; probably an entry level 1080p GPU like the R7 260X. So then I thought of getting a Corsair CX500M instead of the Corsair CX430M but I heard that getting overkill PSUs decrease effeciency of the PC components. Is this true at all?

 

[Mr5oh]

Generally power supplies are most efficient somewhere around half load. So if you go overboard on the PSU it will be operating at very little load where it is less efficient. This means wasted energy, and more heat.

That being said, in most cases we are talking 2-5% difference, so it doesn't make a huge difference.

 

[Robert Cook]

what you have heard, that is false, if anything, more overkill PSUs tend to have better power control and thus it may prolong device use by a small amount. the only disadvantage is that you pay more up front, but as you plan to upgrade, a 500 watt PSU is a good idea.

 

[Robert Cook]

Mr5oh raises the point of efficiency over varying load, however it is indeed minimal and does not effect other components at all. also when you get the GPU, it will be running at a higher load so it really there is not any solid reason I can think of to not get a better PSU like that 500 watt one.

 

[Mr5oh]

No overkill on the power supply still wastes energy and creates extra heat as it won't be as efficient. A quality power supply will have no problems keeping voltages where they should be at half load where its most efficient

 

[Mr5oh]

I am with Robert though, I would get the 500 now anyways.

 

[Robert Cook]

^ but then he has to spend again on a better PSU when he needs one...

 

[Mr5oh]

That's why I said the 500 would be fine now. That way even if he bought a higher end card like a GTX 970, it still only load the PSU to about 50% leaving plenty of headroom, even if he wanted to over clock.

 

[ssddx]

a 500w will be fine for an a10 with possibility to upgrade to an entry level graphics card down the road. i would not be throwing any very high end power hungry cards in there a the cx's really arent that great of a psu (passable) but for your needs it should work. i'd rather see you use a seasonic/xfx unit as they are more reliable but that is your choice.

its true about efficiency. at both low and high load efficiency drops off. for example https://tpucdn.com/reviews/Corsair/CX430_V2/images/efficiency.jpg which is the cx430 efficiency curve. its also true that the power savings is also going to be very minimal. i wouldnt worry about it too much as what you're thinking is fine.

 

[bignastyid]

Nothing wrong with getting an overkill PSU especially where you are planning to upgrade later. However I would advise against the Corsair CX series, while they are not bad to the point of being a danger to the system they are not very reliable due to poor secondary capacitors. You can get a 550w EVGA GS which is a much higher quality unit, fully modular and more efficient(gold rated) for a couple bucks more(after mir).
http://pcpartpicker.com/part/evga-power-supply-220gs0550v1
Or the 520w Antec HCG which would be cheaper(after mir) and is also a higher quality unit.
http://pcpartpicker.com/part/antec-power-supply-hcg520m

 

[mee_wanton]

Nothing wrong with getting an overkill PSU especially where you are planning to upgrade later. However I would advise against the Corsair CX series, while they are not bad to the point of being a danger to the system they are not very reliable due to poor secondary capacitors. You can get a 550w EVGA GS which is a much higher quality unit, fully modular and more efficient(gold rated) for a couple bucks more(after mir).
http://pcpartpicker.com/part/evga-power-supply-220gs0550v1
Or the 520w Antec HCG which would be cheaper(after mir) and is also a higher quality unit.
http://pcpartpicker.com/part/antec-power-supply-hcg520m

Thanks. Although I didn't pick this as the solution you have also been very helpful

 

[mee_wanton]

a 500w will be fine for an a10 with possibility to upgrade to an entry level graphics card down the road. i would not be throwing any very high end power hungry cards in there a the cx's really arent that great of a psu (passable) but for your needs it should work. i'd rather see you use a seasonic/xfx unit as they are more reliable but that is your choice.

its true about efficiency. at both low and high load efficiency drops off. for example https://tpucdn.com/reviews/Corsair/CX430_V2/images/efficiency.jpg which is the cx430 efficiency curve. its also true that the power savings is also going to be very minimal. i wouldnt worry about it too much as what you're thinking is fine.

Thanks. I'm now thinking of getting a Seasonic G-series 550W PSU What kind of GPUs can this handle?

 

[Mr5oh]

Thanks. I'm now thinking of getting a Seasonic G-series 550W PSU What kind of GPUs can this handle?

SeaSonic is always a good choice. Even the GTX 980 only recommends a 500 watt power supply. Nvidia cards are much more efficent than AMD cards though.