2015? Cortex A7 was released in 2011 to be a lower performance energy efficient in-order core. It's significantly slower per clock than Cortex A9 released in 2007!
If you want fairness, just compare it to any Xeon available in 2007 running with just a few watts.
The power efficiency and core count has increased tremendously on Intel CPUs with Sandy Bridge first and late with Haswell. For the same TDP you easily get 8-12 HSW cores these days.
ARM CPUs have likely improved to a similar extent, but given that CPUs are getting "wider" and more sophisticated in terms of caches, power efficiency, etc. it is very hard to extrapolate from assessments made based on hardware that uses >5y old technology.
https://www.arm.com/about/newsroom/arm-unveils-its-most-ener...
> Broadcom BCM2836 (quad-core A7 + VideoCore IV GPU), designed specifically for Raspberry Pi 2[7]
No, it says BCM2836 was designed specifically for Raspberry Pi 2. Cortex A7 is a pretty old design, probably that way RPi 2 costs could be kept low.
Edit:
Here's Anandtech 2011 article about Cortex A7:
http://www.anandtech.com/show/4991/arms-cortex-a7-bringing-c...
Wikipedia's Cortex series DMIPS/MHz table. It says Cortex A7 (1.9 DMIPS/MHz) is roughly as fast per clock as Cortex A8 (2.0 DMIPS/MHz) released in 2003:
"Might it be feasible to replace our current infrastructure¹ with an arm based solution², and at the same time: Can we benefit from more cores, lower clock speeds"
1: The article uses their current dev system - there's no reason to buy a shiny new setup if that dev system works fine today and is 'fast enough'
2: The article explicitly mentions upcoming arm8 server boards but uses RPi2s as a general (and low) approximation for 'cheap arm performance' and to test their setup in a multi-node environment (vs. 'one single vm')
I think the article explains quite well what it wanted to do and doesn't claim 'arm is better' or anything like that. For their workload, using Erlang/OTP and their real world application, a multi-node arm-based architecture might be feasible.
Stupid.
ARM design cores since years as IP cores. Then there are chip makers who decide to use these cores or not depending on business opportunities.
Actually come to think of it, CPUs from five years ago are not bad; I can see a future in a secondhand CPU market, given how CPU's don't really break from usage (normally).
As usual, this follows a statistical distribution. An old CPU isn't guaranteed to break, but it is more likely to, especially if it's been overclocked and/or run without good cooling.
That iSCSI SAN was probably bloody expensive, yet a pair of SSDs today which are orders of magnitude cheaper would run circles around it. OP is storing text documents, so doesn't need a huge disk.
If you'd go for maximum CPU matching the quoted price instead, you'd easily get 8-16 cores each faster than the old Xeon cores in question depending on CPU model and other specs.