[geeks] Ran the numbers - V240

[Lionel Peterson]

On a whim, I googled "HDMI kvm" and found that such beasts do exist, and if I
can keep my 'RPi Datacenter' down to 4x machines, this $70 KVM would give me a
full local console on each RPi:

https://m.ebay.com/itm/Bytecc-KVM-4UHM-4X1-USB-HDMI-KVM-Switch/251941213985

As a bonus, it includes HDMI and USB cables, and carries audio in/out of the
RPis to 1/8"...

And the Etsy 4x desktop Case looks like this:

https://www.etsy.com/listing/271008828/tiny-raspberry-pi-server-rack-cluster

And for 'super compute applications' 12x RPi in a 2U rackmount enclosure, this
is available:

https://www.etsy.com/listing/544554171/raspberry-pi-storage-rack-rackmount

Of course, this 2U rack option precludes the use of the HDMI connectors on the
RPis, but then again, who 'needs' a local GUI console on a Linux server? I'm
not sure how the 12x rack chassis powers the RPis, perhaps jumpers to header
pins? Maybe you have to source some right angle micro USB power leads...

There are many additional options, these are just representative samples.

Lionel

> On Nov 9, 2017, at 8:17 AM, Lionel Peterson <lionel4287 at gmail.com> wrote:
>
> Wow.
>
> So last night I sat down and ran the numbers, and I can see why sun
> V240 are available so cheaply... The cost to run them is quite high!
>
> Here in Texas, using a state average of 9 cents/KWhr, the numbers look
> like this:
>
> 24 hours/day x 365 days/yr equals 8,832 hr/yr
>
> The fully-loaded V240 consumes 385 watts/hr, based on an in-line
"watt-a-meter".
>
> So to run this machine for a year the cost is:
>
> 385 watts/hr x 8,832 hr/yr equals 3,400,320 watts/yr, and when divided
> by 1,000 watts/KW
> give you an annual power appetite for the V240 as 3,400 KWhr/yr.
>
> Multiply the 3,400 KWhr/yr times the cost per KWhr of $0.09/KWhr and
> you are looking at $306/yr.
>
> Divide that $306 by 12, and that means running the machine for a month
> will add about $25.20 to my monthly power bill.
>
> Wow.
>
> For my 24x7 purposes, I was going to run a handful (5) of small VMs,
> serving up small personal websites - I can almost justify the monthly
> cost (it would work out to $5/month per site), but then something
> caught my fancy, a nifty rack that is no bigger than a half gallon
> carton of milk that holds 6x Raspberry PI boards for about $30, and
> that got me thinking...
>
> I googled "power consumption raspberry pi 3" (no quotes) and found
> that at 400% CPU load (all 4x cores running at 100%, worst-case), the
> Pi 3 consumes about 750 ma/hr or 3.7 watts/hr.
>
> Running the same calculations again, a single RPi 3 consumes about 34
> KWhr/yr, and at a cost of $0.09/KWhr, a single RPi 3 is about
> $3.94/yr, or about $0.75/month. And thinking about my application, a
> single RPi 3 could likely handle the any worst-case load any of my
> sites would ever see, so the numbers come down to this:
>
> To run the V240 on older Solaris without access to security patches
> (but scoring booku "Geek Points for running a public Solaris web
> server at home) would cost me $5/month. Hardware costs are zero, I
> have the server already.
>
> To run 5x Raspberry Pi 3 running Linux on them, with full access to
> security patches (and scoring slightly fewer "Geek Points" for having
> a Raspberry Pi datacenter on my desktop) would cost about $3.75/month.
> Hardware costs are steeper:
>
> 5x Raspberry Pi 3B at $35/each = $175
> 5x 32 Gig microSD cards at $10/each = $50
> 1x multi-port cellphone charger (6x USB ports, 60 Watt capacity) = $20
> 5x micro USB to USB cables (power for RPis) = $10
> 5x 1 ft Cat 5 cables = $10
> 1x 8 port Ethernet switch = $15
> 6x RPi rack from etsy = $30
>
> Total Hardware cost: $310
>
> Total first-year cost is nearly identical ($0 + $306 = $306/yr for
> V240, $310 + (5x $4/yr for 5 RPi) = $330/yr for the desktop RPi
> datacenter, but for year 2 of operation the cost is another $306 for
> the V240 vs $20 for the RPi datacenter...
>
> Looks like I may be going out shopping for some Raspberry Pis!
>
> Thought others might find the math/numbers interesting.
>
> Lionel
> --
> Lionel Peterson
> lionel4287 at gmail.com