Comment by stoltzmann

3 years ago

>While the machine itself isn’t expensive, it is not cheap if you consider the cost to operate. A machine like this is very power-hungry. Suppose the power consumption is 1000W per hour.

Alright, a server will be more power hungry than e.g. your desktop, but... This specific Dell R630 has 2x 750W PSUs in it. That 750W is the maximum rating of one power supply, and there's 2 of them for redundancy - not for increased power intake. That server will run at 750W maximum - but that is the absolute, absolute maximum power it should draw. It's when you have all the rails loaded to the limit and running the server to the ground.

A more realistic scenario would be e.g. 100W or so on average.

The worse problem if running this server at home would be the terrible small high-RPM fans they have in 1RU servers. The loud high-pitched whine of them will drive you nuts. A better idea would be to get either a lower-power 1RU pizza box, or something larger that can take larger fans - replacing the fans with something quieter and adjusting the fan controller to spin at lower RPMs.

>1000W per hour

This is just wrong.

7 comments

stoltzmann

mysteria 3 years ago

I run rack servers at home and I 100% call BS on that 1000W number. My older Ivy Bridge Xeon servers only consume 50W on idle, 100W with some load, and <200W with all cores fired running P95 or something. The noise is a concern but it's not an issue if you put it in your basement.

buffington 3 years ago

I couldn't do it with a single R420. When that first booted up in my basement - good lord I wasn't prepared. There wasn't a soul in my house who wasn't suddenly in there with me trying to understand what had just happened.
Adjusting the RPMs in software helped a little, but even at the lowest speeds, it was a hovercraft. It had to go.

livueta 3 years ago

Yeah, I have a bunch of fully loaded R720XDs and with 12 3.5" SATA drives they sit at about 120-140W, both according to the lights-out console and wall wart meters.

mmastrac 3 years ago

I swapped out the screamer fans for Noctuas on a 1U server and it's significantly better. Needed a custom mini PCB and a bios setting to ignore fan speed feedback but it's extremely quiet and runs cool.

I don't think it uses much power when idle either. I think that rack servers being expensive is a myth.

strobe 3 years ago

noise actually not that bad with some bios configuration tricks - I used to run dell r720 and r420 together with ~20 HDDs near my desk table and most of the day noise was close to some non-silent gaming PC/workstation. Only problem was if is some need to reboot it, in that case it just blow fans to full power and it's loud like vacum cleaner that you for sure don't wanna to use at middle of the night.

november84 3 years ago

An addition, you have the ability to chain the PSUs for increased total power at the loss of redundancy.

justsomehnguy 3 years ago

> and there's 2 of them for redundancy - not for increased power intake

Ahem:

    System Headroom
        Statistic       Reading 
        Instantaneous   1528 W | 5215 BTU/hr 
        Peak            1346 W | 4594 BTU/hr

That's R720 with dual "PWR SPLY,750WP,RDNT,FLX" PSUs. You can configure them for the redundancy mode and you can cap the maximum power per PSU:

    Hot spare is a power supply feature that configures redundant Power Supply Units (PSUs) to turn off depending on the server load. 
    *This allows the remaining PSUs to operate at a higher load and efficiency.*
    This requires PSUs that support this feature, so that it quickly powers ON when needed.

    Redundancy Policy:

         Not Redundant — In this mode, failure of a single PSU can power off the system.

         Input Power Redundant — In this mode, the system is functional in the event of failure of a PSU input circuit,
         provided the PSUs are connected to different input circuits. This is also called AC redundancy.

> This is just wrong.

But yes, these guys idle at 150W at have around 300W under load with dual CPUs and a lot of RAM.