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> Keep in mind that this Xeon (E5620) was released in 2010, whereas the Cortex A7-Quad seems to be from 2015? 2015? Cortex A7 was released in 2011 to be a lowe

by vardump 11y ago

> Keep in mind that this Xeon (E5620) was released in 2010, whereas the Cortex A7-Quad seems to be from 2015? 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.

claudius 11y ago
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 The point is, the Xeon is definitely outdated and the Cortex A7 seems to be a little bit dusty as well, so…what exactly was the point of this comparison?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.
PinguTS 11y ago
To back that up, it was release in October 2011: https://www.arm.com/about/newsroom/arm-unveils-its-most-energy-efficient-application-processor-ever-with-biglittle-processing.php https://www.arm.com/about/newsroom/arm-unveils-its-most-ener...
slizard 11y ago
I think the comparison is still quite dangerous: possibly unfair, probably telling little about current hardware. 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.

by vardump 11y ago

claudius 11y ago

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.

PinguTS 11y ago

To back that up, it was release in October 2011: https://www.arm.com/about/newsroom/arm-unveils-its-most-energy-efficient-application-processor-ever-with-biglittle-processing.php https://www.arm.com/about/newsroom/arm-unveils-its-most-ener...

slizard 11y ago

I think the comparison is still quite dangerous: possibly unfair, probably telling little about current hardware. 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.