Platinum or gold rated psu?

[DominicNikon]

Hello, i'm getting a new npower supply for my  build and i am trying to decide between two power supplies.  The corsair hx1000i (platinum) or the rmx1000 (gold) power supplies. Is a platinum rated psu worth the $50 extra over the gold rated? My specs are an AMD Ryzen 9 3900x 2 gtx 980s and 32gb ddr4 all of the parts will be overclocked with a custom loop and a total of 12 fans. 

[Samfisher]

Gold is enough.

[Spotty]

The HXi also offers digital monitoring (iCue) and ability to switch between single rail and multi rail modes.

[DominicNikon]

Just now, Spotty said:

The HXi also offers digital monitoring (iCue) and ability to switch between single rail and multi rail modes.

What is the benefits of that?

[Spotty]

Just now, DominicNikon said:

What is the benefits of that?

The digital monitoring allows you to view information in software about the power supply, such as how much power the system is drawing, efficiency, etc. The power supply has a cable that plugs in to a motherboard USB header and reports those values in Corsair's iCue software.

 

Single rail is where all of the power on 12V is delivered over a single rail on the power supply. For the 1000W PSUs you're looking at, that's up to 83A (1000W). In theory if there's a certain type of failure it could be possible for something to draw 83A through a single cable and the PSU will be thinking "This is fine". It'll only be when it exceeds that and OPP (Over Power Protection) trips that the PSU shuts down, or if another protection trips before...

With multi rail that 1000W for the 12V is split up in to multiple smaller 12V rails. In this case they're limited to a max of 40A each (480W) so if a rail is drawing more than 40A OCP (Over Current Protection) will trip the PSU to shut it down. It varies depending on how the power supply is configured, but just as an example you might have one rail for CPU power connectors, another 1 or 2 rails for GPU power, and another rail for motherboard & peripheral.

Though the type of failures where this would happen are rare, and you can still have situations where you ruin your PSU long before OCP trips as well, like when using SATA to PCIe adapters trying to power a graphics card. The cable will fry since it's not rated for that load even though it might only be drawing 15A through the rail that handles peripheral connections, well below the 40A OCP limit. (Which is probably what happened here and here where you can see the 12V pin has melted)

 

Most power supplies on the market are single rail, and some companies don't even sell multi rail power supplies. Multi rail (especially how Corsair implements it here being able to toggle between single rail and multi rail) is more expensive which is why it's a feature only available on their high end premium models.

For more (better) explanation see this video:

 

There is also the HX1000 which lacks digital monitoring but is still 80+ Platinum and allows for switching between single rail and multi rail modes. It should be priced in between the RMx and HXi. There's also the RM1000i which is 80+ Gold has digital monitoring and and switch between single rail and multi rail and should be priced between the RMx and HX. Plus plenty of non-Corsair power supplies that can be considered as well.

[Guest]

2 hours ago, DominicNikon said:

Hello, i'm getting a new npower supply for my  build and i am trying to decide between two power supplies.  The corsair hx1000i (platinum) or the rmx1000 (gold) power supplies. Is a platinum rated psu worth the $50 extra over the gold rated? 

No.  Because what you are paying for is not Gold vs. Platinum, but the fact that the HX1000i has digital monitoring and control of fan speed, voltage, current, etc. and RM1000x is just a standard analog PSU.

[DominicNikon]

18 hours ago, jonnyGURU said:

No.  Because what you are paying for is not Gold vs. Platinum, but the fact that the HX1000i has digital monitoring and control of fan speed, voltage, current, etc. and RM1000x is just a standard analog PSU.

ok, the digital monitoring sounds cool. off topic but for the hardware i listed is 1000watts a good size or should i go lower? psu calculators put me at around 550 watts but one put me at 800 watts. 

[Guest]

35 minutes ago, DominicNikon said:

ok, the digital monitoring sounds cool. off topic but for the hardware i listed is 1000watts a good size or should i go lower? psu calculators put me at around 550 watts but one put me at 800 watts. 

If any "PSU calculator" put you at 550W, then 550W ~ 650W is the most you need.  

 

The 800W calculator sounds like it's on crack unless you're using SLI or multiple workstation cards.  We don't know what your build is.

 

[DominicNikon]

36 minutes ago, jonnyGURU said:

If any "PSU calculator" put you at 550W, then 550W ~ 650W is the most you need.  

 

The 800W calculator sounds like it's on crack unless you're using SLI or multiple workstation cards.  We don't know what your build is.

 

my build is:

amd ryzen 9 3900x (overclocked)

2 sli GTX 980 (overclocked)

32gb 3200mhz DDR4

1SSD

2 7200rpm HDD

12 rgb static pressure fans

30 watt pump (at full power)

 

[Spotty]

12 minutes ago, DominicNikon said:

my build is:

amd ryzen 9 3900x (overclocked)

2 sli GTX 980 (overclocked)

32gb 3200mhz DDR4

1SSD

2 7200rpm HDD

12 rgb static pressure fans

30 watt pump (at full power)

 

rough guestimates, probably overestimating a little...

CPU = 150W (under CPU intensive load, gaming probably be <100W)
GPU = 2x200W (let's round up to 250W each since its OC'd under liquid)
Ram = 10W

SSD = 3W
2x HDDs = up to 20W (when spinning up)

12 RGB fans = 2W each (25W total)

30W pump = 30W

Motherboard + USB peripherals etc = 30W or so probably

 

 

You probably won't be running Prime95 + Furmark + CrystalDiskMark all at the same time so you probably won't ever get close to that figure in real world use though. I'd personally go for at least 750W, which is usually when you get the 4x PCIe connectors required for your 2 graphics cards anyway. The HXi series you were considering starts at 750W models. I don't think you'd be wasting money if you went with an 850W or even the 1000W you were planning, since I think the price difference between 750W and 850W models is only like $10.

 

If you already have the system and are using it with a different power supply you are replacing then you could just grab a wall power meter and see how much power it's drawing from the wall and work off that.

[DominicNikon]

7 minutes ago, Spotty said:

I don't think you'd be wasting money if you went with an 850W or even the 1000W you were planning, since I think the price difference between 750W and 850W models is only like $10.

out of 750 850 or 1000w which one would you go for? Do i need to worry about the psu's not using full efficiently at idle from the psu being too big?

[Spotty]

13 minutes ago, DominicNikon said:

out of 750 850 or 1000w which one would you go for? Do i need to worry about the psu's not using full efficiently at idle from the psu being too big?

You're still considering the HXi? Having a quick look at prices on Newegg, the 750W is $193, the 850W $201, and 1000W is $240. I'd go the 850W since it's only an extra $8, but I don't think the 1000W for an extra $47 is going to give you any worthwhile benefit.

 

You can look up detailed efficiency testing for various power supplies at cybenetics.com. Top graph is overall efficiency graph and bottom table shows more detailed low load efficiency. Even at only 60W system power draw it still reaches 84% efficiency. I'd guess that your system with 2 cards would idle higher than that. So yeah, I don't think you'd have any issues with efficiency drop off at low loads.

[DominicNikon]

48 minutes ago, Spotty said:

I'd go the 850W since it's only an extra $8, but I don't think the 1000W for an extra $47 is going to give you any worthwhile benefit.

Ok, thank you. i think i will get the hx850i powersupply