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Wikipedia¹ lists a Cortex A7 „designed specifically for Raspberry Pi 2“. The Raspberry Pi 2 was released in 2015, so the CPU was released in 2015? [1] https://

Wikipedia¹ lists a Cortex A7 „designed specifically for Raspberry Pi 2“. The Raspberry Pi 2 was released in 2015, so the CPU was released in 2015? [1] https://en.wikipedia.org/wiki/ARM_Cortex-A7 https://en.wikipedia.org/wiki/ARM_Cortex-A7

vardump 11y ago
From the Wikipedia article: > 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-cheaper-dualcore-more-power-efficient-highend-devices 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: https://en.wikipedia.org/wiki/Comparison_of_ARMv7-A_cores https://en.wikipedia.org/wiki/Comparison_of_ARMv7-A_cores
- claudius 11y ago
  Interesting. So how would a reasonably new ARM core compare to this? The point is, the Xeon is definitely outdated and the Cortex A7 seems to be a little bit dusty as well, so…what exactly was the point of this comparison? Two CPUs from two different (or equal, if you take 2010/2011) points in time are roughly comparable?
  - darklajid 11y ago
    I feel the point of the comparison was answering the question "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.
    - vidarh 11y ago
      But then pointing out the cost of their current system is confusing matters - as I've pointed out in another comment, a similar performance system today can easily be had for 1/5th of the price they list. They're comparing against a system that is old, slow and expensive.
PinguTS 11y ago
Yeah, Wikipedia says, that ARM designed a processor specifically for the Raspberry so it must be right. 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.

vardump 11y ago

From the Wikipedia article: > 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-cheaper-dualcore-more-power-efficient-highend-devices 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: https://en.wikipedia.org/wiki/Comparison_of_ARMv7-A_cores https://en.wikipedia.org/wiki/Comparison_of_ARMv7-A_cores

claudius 11y ago
Interesting. So how would a reasonably new ARM core compare to this? The point is, the Xeon is definitely outdated and the Cortex A7 seems to be a little bit dusty as well, so…what exactly was the point of this comparison? Two CPUs from two different (or equal, if you take 2010/2011) points in time are roughly comparable?
- darklajid 11y ago
  I feel the point of the comparison was answering the question "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.
  - vidarh 11y ago
    But then pointing out the cost of their current system is confusing matters - as I've pointed out in another comment, a similar performance system today can easily be had for 1/5th of the price they list. They're comparing against a system that is old, slow and expensive.

PinguTS 11y ago

Yeah, Wikipedia says, that ARM designed a processor specifically for the Raspberry so it must be right. 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.