Our review of the Boston Viridis, one of the first Calxeda ECX-1000 based servers, was a pretty weird one. Instead of trying out different server workloads, we deliberately went for one of the few scenarios where the server might make sense: hosting light webservers. There were a few others like Content Delivery Network server or storage server, but those were about it. The quad ARM Cortex A9 inside the ECX-1000 was faster than the contemporary Atom SoCs, but missed the RAM capacity and raw performance of low power Xeons to be an alternative in most server workloads. The measured (!) 8 Watt per server node was however simply spectacular and the network fabric was one of the best in the industry. Calxeda was on the right track - they only needed more RAM and single thread performance in a server node. 

Calxeda has announced its second generation server SoC yesterday, the EnergyCore ECX-2000. Based upon the more powerful ARM Cortex A15, this new SoC should be able to deliver up to twice as much performance at 1.8 GHz than the ECX-1000 at 1.4 GHz and offer four times more RAM (16 GB per node). Although we will not believe the performance claims until we have tested them ourselves, it is not impossible to speculate. Anand compared the Google Nexus 10 with the Samsung Galaxy Tab 3 8.0: the former has a Samsung Exynos 4 based upon a dual Cortex A15 at 1.7 GHz inside, the latter a very similar Samsung design, the 4212 based upong a dual Cortex A9 at 1.5 GHz. 

Benchmark A15 vs A9
Sun Spider 1.0 140%
Mozilla Kraken 176%
Octane v1 168%

It is impossible to estimate the performance of server SoCs by looking at browser benchmarks on tablet SoCs, but it gives us rough idea of how much extra crunching power the A15 delivers. At 7-zip.com we can compare an A15 at 1.7 GHz (Samsung Exynos 5250) with an A9 at 1.4 GHz (Samsung Exynos 4412):

Benchmark A9 A15 A15 vs A9
LZMA compression 1200 2270 189%
LZMA decompression 2400 3560 148%

As we posted before, the LZMA compression does have some similarities with typical server workloads. A Xeon "Sandy Bridge EP" 1.8 GHz scored 2793 with one thread, an EnergyCore ECX-1000 at 1.4 GHz scored 833 according to our own benchmarking. So we can estimate that a ECX-2000 would probably score around 1600, or similar to a modern Xeon at 1 GHz. Not earth shattering, but when you start looking at power consumption these numbers start to make sense.


While the ECX-1000 needed 5 (1.1 GHz) to 6W (1.4 GHz per SoC), according to Calxeda the ECX-2000 needs about 7 to 10W (1.8 GHz). This equates to about 2.5 W per 1.8 GHz core. The best low power Xeon, the Xeon E3-1230L V3, has 4 cores (with HT) at 1.8 GHz with a TDP of 25W, or around 6W per physical core. Even though we do not know exactly what kind of server performance the ECX-2000 at 1.8 GHz will deliver, the limited data that we have makes it very likely that the ECX-2000 is going to be very interesting from a performance/watt point of view.

Of course, the real challenge will be the newly released Intel Atom C2000. Let us compare the new Calxeda SoCs with Intel's second generation of Server SoCs.

Intel Atom C2000 versus Calxeda ECX-2000
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  • Khato - Tuesday, October 29, 2013 - link

    Awwwww, from the title I was all excited to see an actual review of these two server SoCs, not just a feature comparison. Oh well, just have to wait awhile longer for that to come eh?
  • krumme - Tuesday, October 29, 2013 - link

    Johan just couldnt wait :). I understand him. From this arm generaion on its starting to become interesting. When was the last time something this happened?
  • Khato - Tuesday, October 29, 2013 - link

    If by interesting you mean a performance bump in line with expectations and the ability to address enough memory for it not to be a major limitation, than sure, this generation becomes interesting. Personally I found the first iteration more interesting for the simple fact that it actually beat Intel to the punch and provided a superior solution for the particular niche it was good for. Whereas this time around, well, the C2530 is almost at the bottom of Intel's Avoton lineup - only the one dual core model is below it. The more important point being that for any reasonably threaded workload Intel offers 8 core SKUs which, due to the fixed power consumption per node, greatly increase performance while only bumping up power consumption by ~33%.

    The next round might be a bit more interesting but I doubt it. Note how the ECX-2000 projected performance increase is pretty much exactly as much as the projected power increase over the ECX-1000? And that's with going from a 40nm process to 28nm. Why exactly should we expect anything more from the next generation?
  • JohanAnandtech - Wednesday, October 30, 2013 - link

    Your reasoning has some good points. However: the higher RAM capacity and CPU performance really allows that new kind of apps run on this thing. Apps that can benefit from the excellent network fabric for example. It will be interesting to see which realworld apps are bottlenecked by the limited CPU power and which ones are bottlenecked by network. Realworld server applications can sometimes be extremely different from the typical benches used. The ECX-2000 will not win any raytracing bench, but Calxeda does have a fighting chance turn as a Content Delivery Server or Drupal based server. All I am saying is, don't judge on raw performance or perf/watt.
  • wsw1982 - Wednesday, October 30, 2013 - link

    So, the point is "don't judge on the performance, don't argue on the perf / watt, don't judge on the software, don't judge on the availability, don't judge on the power consumption (no data is given)." But see, "we have 10 g eth"
  • JohanAnandtech - Wednesday, October 30, 2013 - link

    I am saying that raw perf/watt does not translate in realworld perf/watt when running realworld server apps. The S1260 looked on par with the ECX-1000 in the benchmark: about the same raw performance (integer crunching benches) and 8.5W vs 6W. The reality was that a S1260 server node needed 15 to 20W (vs 8W) and performed up to twice as slow in real server loads. That is 4-5 (!!) worse perf/watt ratio than expected from integer benches and TDP. Not saying the C2000 will be the same, just illustrating how far real server workloads can be from the other benchmarks.
  • hoboville - Thursday, October 31, 2013 - link

    He's saying the ARM chip, like all good RISC chips is good for certain applications like CDN. Real world and on other applications it might not hit its stride.

    Real world also means that, because the ARM has less RAM and fewer cores, it has the potential to be bogged down in scenarios where there is a higher demand than the cache / RAM / threads can handle. It may be that those requests only require a small amount of network bandwidth, but if the processor can't schedule those tasks...then the CPU is a problem. However, if the CPU is handling a simple decode of a massive file, it can stream the results faster than network bandwidth. Real world perf is subject to a large degree of variability in task type.
  • JohanAnandtech - Wednesday, October 30, 2013 - link

    I understand. We simply have to wait until the ODM solutions on ECX-2000 are validated.
  • geekfoo - Friday, November 1, 2013 - link

    wow, whoever they have laying out these moonshot module/sleds wants shooting :)

    you could easily get 8 or even 16 SoC in that same space today im sure, perhaps even more.

    Oh and Johan as you say you cant really compare OC but you should probably go into petty cash and get a few cheap Hardkernel ARM big.LITTLE A7 + A15 Exynos 5410 Octa-Core ODROID-XU's for generic testing etc

  • geekfoo - Friday, November 1, 2013 - link

    i find these older cortex tests interesting too
    and PandaBoard bearing an OMAP4430 with 1.0GHz Cortex-A9 MPCore)

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