How do servers deliver power?

[TubsAlwaysWins]

Ok so ive been having a mini debate in my mind about server power supplies. Here it is:

If a server has redundant power supplies, each is 500W (so 2x500W PSU's), and the server itself has a CPU and HDD's or something that draws 500W exactly, (So on a normal computer a 500W PSU is delivering 500W), do the power supplies (in the server):

A. Draw 500W each, so drawing 1000W from the wall

B. Draw 250W each for a total of 500W from the wall

C. One draws 500W while the other draws 0W from the wall

 

Just never could figure it out. Sorry if its confusing

 

[themctipers]

depends.

[TubsAlwaysWins]

7 minutes ago, themctipers said:

depends.

?

[tt2468]

17 minutes ago, TubsAlwaysWins said:

Ok so ive been having a mini debate in my mind about server power supplies. Here it is:

If a server has redundant power supplies, each is 500W (so 2x500W PSU's), and the server itself has a CPU and HDD's or something that draws 500W exactly, (So on a normal computer a 500W PSU is delivering 500W), do the power supplies (in the server):

A. Draw 500W each, so drawing 1000W from the wall

B. Draw 250W each for a total of 500W from the wall

C. One draws 500W while the other draws 0W from the wall

 

Just never could figure it out. Sorry if its confusing

 

That totally depends on the server. number one isn't physically possible, as the spare 500w has to o somewhere.

[Electronics Wizardy]

17 minutes ago, TubsAlwaysWins said:

Ok so ive been having a mini debate in my mind about server power supplies. Here it is:

If a server has redundant power supplies, each is 500W (so 2x500W PSU's), and the server itself has a CPU and HDD's or something that draws 500W exactly, (So on a normal computer a 500W PSU is delivering 500W), do the power supplies (in the server):

A. Draw 500W each, so drawing 1000W from the wall

B. Draw 250W each for a total of 500W from the wall

C. One draws 500W while the other draws 0W from the wall

 

Just never could figure it out. Sorry if its confusing

 

Depends on the server

With 2 servers here are you options(max 500w due to redundancy

1. Both psu's are always running at half power.

2. With some servers there is a option to use one psu with another idling. This saves power.

 

With 3 or more psu's you have 1 always in standby. so 2+1. 

 

You limited to the power of all the psu's -1

[themctipers]

Just now, TubsAlwaysWins said:

?

if you wired one to the motherboard and another to the hdds, it would be similar to option B

A is probably not likely, i dont know tho.

C if all of the components were connected to one PSU

[TubsAlwaysWins]

3 minutes ago, themctipers said:

if you wired one to the motherboard and another to the hdds, it would be similar to option B

A is probably not likely, i dont know tho.

C if all of the components were connected to one PSU

So what about on something like a Dell C2100?

[themctipers]

Just now, TubsAlwaysWins said:

So what about on something like a Dell C2100?

dunno

[leadeater]

Depends on both the server, the current load and the configuration you order the server in.

 

Servers with multiple power supplies have a distributor that the power supplies connect to, power is delivered from this. These are either active/active or active/passive style, or N -1 for 3 or more.

 

For example with an active/active style distributor if the server has two 500W power supplies and you are drawing 500W then each power supply will be delivering 250W, if you then go above 500W you have now lost resiliency so in the event of a power supply failure the server will shut off. Some servers will not let you draw more than what a single power supply can give and this is can either be configurable in the bios or one time configured at purchase (hardware), I call this active/passive when really it's not but makes it clear you cannot go above the draw of 1 PSU.

 

There is typically monitoring connectivity of the power distributor that connects to the motherboard so the bios can control the power etc. These advanced power control features are found only on products from HP/IBM/Dell and not whitebox/build your own.

[TubsAlwaysWins]

3 hours ago, leadeater said:

Depends on both the server, the current load and the configuration you order the server in.

 

Servers with multiple power supplies have a distributor that the power supplies connect to, power is delivered from this. These are either active/active or active/passive style, or N -1 for 3 or more.

 

For example with an active/active style distributor if the server has two 500W power supplies and you are drawing 500W then each power supply will be delivering 250W, if you then go above 500W you have now lost resiliency so in the event of a power supply failure the server will shut off. Some servers will not let you draw more than what a single power supply can give and this is can either be configurable in the bios or one time configured at purchase (hardware), I call this active/passive when really it's not but makes it clear you cannot go above the draw of 1 PSU.

 

There is typically monitoring connectivity of the power distributor that connects to the motherboard so the bios can control the power etc. These advanced power control features are found only on products from HP/IBM/Dell and not whitebox/build your own.

So if the server is redundant with 2x500W PSU's it can only draw 500W max. But if it is redundant does it do 250W a PSU and can instantly switch over once one fails?

[gamerking]

1 hour ago, TubsAlwaysWins said:

So if the server is redundant with 2x500W PSU's it can only draw 500W max. But if it is redundant does it do 250W a PSU and can instantly switch over once one fails?

some use both some only will use 1 psu other is idle till a failure happens. if its under the load of a single psu can handle and you have  redundant  the other one takes the full load without shutting the server off. like the phanteks thing for using 2 psu's to power one system that's the consumer version in my eyes as a redundant psu for a homemade server out of non enterprise parts