It costs roughly the same to build an openstack cluster to server 600 m3.mediums as it does to use AWS. The openstack cluster is not better, but it is good enough. As you add more compute, the DIY solution becomes significantly cheaper, although probably not better.
The original poster used a silly piece of hardware, with no disk, 8GB of ram , and by far the most expensive CPU (in $/CPU) possible, with 18 cores.
The spreadsheet assumes a sane server with 128G of ram and a 300GB disk, which can fit 34 m3.mediums.
I assume you can hire a consultant at $10k/mo on a 3 year contract to spec, install, and operate this system, which, by the way, fits in 1 rack.
I assume you buy a 1gbps internet link for $3k/mo; and you have a budget of $10k for the switch, which should include maintenance.
These numbers show it would cost $222k in capital; which depreciated over 3 years (or do a 3 year lease) would cost around $6200/mo v. the AWS cost of 30k/mo with on demand.
Add $10k for the consultant, and you're at $16k v. $30k (AWS).
Assume a 50% discount for using Reserved Instances, and the solutions break out about even.
But, notice that 2/3 of your cost is that consultant at $10k/mo. So when you grow larger than the 600 VMs, things get cheaper as marginal costs increase.
There's no question AWS is valuable and the right solution a lot of the time.
The OP made some properly wrong assumption in how to build a hosted compute system, which, when corrected, show a much better cost comparison.
My numbers are also imperfect, but not as imperfect.
Comments
It costs roughly the same to build an openstack cluster to server 600 m3.mediums as it does to use AWS. The openstack cluster is not better, but it is good enough. As you add more compute, the DIY solution becomes significantly cheaper, although probably not better.
Here's my rough spreadsheet..
http://bit.ly/18KOlyd
The original poster used a silly piece of hardware, with no disk, 8GB of ram , and by far the most expensive CPU (in $/CPU) possible, with 18 cores.
The spreadsheet assumes a sane server with 128G of ram and a 300GB disk, which can fit 34 m3.mediums.
I assume you can hire a consultant at $10k/mo on a 3 year contract to spec, install, and operate this system, which, by the way, fits in 1 rack.
I assume you buy a 1gbps internet link for $3k/mo; and you have a budget of $10k for the switch, which should include maintenance.
These numbers show it would cost $222k in capital; which depreciated over 3 years (or do a 3 year lease) would cost around $6200/mo v. the AWS cost of 30k/mo with on demand.
Add $10k for the consultant, and you're at $16k v. $30k (AWS).
Assume a 50% discount for using Reserved Instances, and the solutions break out about even.
But, notice that 2/3 of your cost is that consultant at $10k/mo. So when you grow larger than the 600 VMs, things get cheaper as marginal costs increase.
There's no question AWS is valuable and the right solution a lot of the time.
The OP made some properly wrong assumption in how to build a hosted compute system, which, when corrected, show a much better cost comparison.
My numbers are also imperfect, but not as imperfect.