Corsair RM850 vs Corsair AX860

[Hipstair]

Hello all,

I'm not to far from building a new pc. Right now, i plan to use a 4770K overclocked to 4.4 ghz, 2x8GB Memory, 1 gtx 780 ti (ill be able to add one or two more in the future), 1 HDD, 1 SSD, and some 120mm fans. I plugged my plan into this psu calculator: http://www.extreme.outervision.com/psucalculatorlite.jsp and it came out with a recommended 855 watts for the power supply. I was just wondering if the rm850 would handle it, or whether i should step up to the ax860 or higher wattage power supply. Thanks in advance!

[Erik4boss]

I say since you want three graphics cards, you should get 1100 watt +!

[helping]

RM850 can do it.

 

AX860 (non -i), V850, Pro series (non core) 850 are more favorable though, IMO. 

basically anything KM3, including Seasonic's own units, obviously.

 

like said above, 3 on an 850w is kind of pushing it, and 3 way SLI is almost always...er not good (putting it nicely)

 

If your recommended wattage is 855, I will suggest you to go for at least a 1000W PSU. PSU are only reliable for 80% of their rated capacity. Overloading your PSU can wreck your system in no time.

eh, no

not at all.

 

I'll probably never put a third graphics card in, but I want to be sure I can do it if I ever decide to add it.

you probably are best off assuming you won't for both practical and financial reasons.

why you shouldn't bother is an entire other topic, but if you absolutely must (I implore you not to) 3 way SLI, then a 1000w unit is the way to go.

[Createinator]

Hello all,

I'm not to far from building a new pc. Right now, i plan to use a 4770K overclocked to 4.4 ghz, 2x8GB Memory, 1 gtx 780 ti (ill be able to add one or two more in the future), 1 HDD, 1 SSD, and some 120mm fans. I plugged my plan into this psu calculator: http://www.extreme.outervision.com/psucalculatorlite.jsp and it came out with a recommended 855 watts for the power supply. I was just wondering if the rm850 would handle it, or whether i should step up to the ax860 or higher wattage power supply. Thanks in advance!

If your recommended wattage is 855, I will suggest you to go for at least a 1000W PSU. PSU are only reliable for 80% of their rated capacity. Overloading your PSU can wreck your system in no time.

[Hipstair]

RM850 can do it.

 

AX860, V850, Pro series 850 are more favorable though, IMO. 

 

 

like said above, 3 on an 850w is kind of pushing it, and 3 way SLI is almost always...er not good (putting it nicely)

I'll probably never put a third graphics card in, but I want to be sure I can do it if I ever decide to add it.

[LIGISTX]

For gaming, tri SLI is pretty pointless as stated above. You just don't get enough for your money. Say in two years you want to step up from SLI to tri SLI. You will be better off selling the 2 780ti's and getting 2 more of the new cards, instead of dropping like 500 even then on a third one. It just isn't practical (unless you are building a PC for show, then sure).

 

I say go normal SLI as a plan and the PSU will be fine.

[quan289]

Personally, I would get the AX860, as it is a better build power supply overall. The RM850 would work for you system though.

 

If you want an alternative, it would be helpful to know where you are able to buy from (links). If you are in the US, I would have a look at the EVGA Supernova 850 G2 that's on sale and ends today for $129.99 or $109.99 after MIR. http://www.ncixus.com/products/?usaffiliateid=1000031504&sku=94404&promoid=1320

[WoodenMarker]

If your recommended wattage is 855, I will suggest you to go for at least a 1000W PSU. PSU are only reliable for 80% of their rated capacity. Overloading your PSU can wreck your system in no time.

No, psus are supposed to be able to output at least whatever wattage they label it with--basically 100% or more.

The 80 Plus rating is the efficiency. The unit will draw more wattage out of the wall than what it outputs. 

[Createinator]

No, psus are supposed to be able to output at least whatever wattage they label it with--basically 100% or more.

The 80 Plus rating is the efficiency. The unit will draw more wattage out of the wall than what it outputs. 

Thanks for the clarification!

Will using 100% of the rated capacity of the PSU affect it in any way?

[WoodenMarker]

Thanks for the clarification!

Will using 100% of the rated capacity of the PSU affect it in any way?

More wear and tear but it should be fine if it isn't a crappy unit to begin with. 

[samosnik]

Corsair RM1000

[quan289]

Thanks for the clarification!

Will using 100% of the rated capacity of the PSU affect it in any way?

 

More wear and tear like WoodenMarker had said. It also depends on the unit, as not all power supply are built the same. For example, I don't have a problem running a Seasonic G 550w or the TX550M at 100% output (not that I'm suggesting it btw), but I don't not recommend you do so with a CX600M in practice, as it's not design to do so in which you may experience some stability issues.

 

There are also units that are capable of outputting much more than what they are rated as well. Like the Antec HCP-1200 had shown to be able to power a i7-980x and quad SLI 580s, in which it had pull 2200w from the wall. That equate around 1700wDC.

In which Chiphell had tested it with a 50% overload while still staying well within the excellence range of ATX specification.

[seiny]

No, psus are supposed to be able to output at least whatever wattage they label it with--basically 100% or more.

The 80 Plus rating is the efficiency. The unit will draw more wattage out of the wall than what it outputs. 

Can you explain a little more please, I still don't get it

[WoodenMarker]

Can you explain a little more please, I still don't get it

Ex: If a psu is labeled to output 500w, it should be able to output 500w.

What a psu does is convert AC from the wall to DC for your components. The conversion is not 100% efficient due to some of the power is lost to heat. An 80 Plus certified psu will operate with an efficiency of at least 80%. Higher ratings have higher efficiency curves which change depending on how much load the psu is at. http://en.wikipedia.org/wiki/80_Plus

 

[quan289]

Can you explain a little more please, I still don't get it

 

A power supply job is to take in AC power from the wall outlet and convert it to DC power for your computer to used. This process isn't 100% efficient, in which some of that power will be lost and being wasted as heat. So if your PSU is drawing at 850w at the wall and the PSU is 80% efficient at that load, the PSU is supplying around ~680wDC.

 

Any proper power supply are rated at DC output, so a good 650w continuous PSU is capable to output 650w continuously for your system. If this was a gold unit, that PSU would be pulling around 750w from the wall.

[atrash]

WoodenMarker, on 23 Apr 2014 - 3:59 PM, said:

Ex: If a psu is labeled to output 500w, it should be able to output 500w.

What a psu does is convert DC from the wall to AC for your components. The conversion is not 100% efficient due to some of the power is lost to heat. An 80 Plus certified psu will operate with an efficiency of at least 80%. Higher ratings have higher efficiency curves which change depending on how much load the psu is at. http://en.wikipedia.org/wiki/80_Plus

 

 

i think you got that switched.

[WoodenMarker]

i think you got that switched.

Whoops--thanks for pointing that out.

Fixing it.

[jiyang1018]

Between the 2, I would choose RM. AX series is over priced.

For your build, I would get a Seasonic 1000W Platinum.