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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  • azazel1024 - Tuesday, October 29, 2013 - link

    Granted, it is in no way comparable as the multithreaded performance probably falls WAY short, but as an interesting power consumption comparitor, my home server is based on a G1620 Ivy Bridge chip, uATX board (I forget the make, but H77 based, I want to say Gigabit?), 8GB of memory (2x4GB 1.25v), a pair of Intel CT gigabit NICs (motherboard port disabled), 60GB SSD for a boot/app disc and a pair of 2TB Samsung F4EG drives in RAID0 and a 80+ Bronze 350w PSU.

    Whole thing pulls down 21w at idle and 32w with the drives spun up streaming. During heavy computational loads (as a simple test) the whole system pulls down a hair over 50W with both cores at 90+% and the HDD spun up.

    I'd personally love to see the system as a whole pull down half those numbers. I really am curious looking, more from a comodity/lower requirement stand point, the newer Atom based Celeron and Pentium chips.

    I'd be curious to see if anything exists with at least four SATA 6Gbps ports, RAID0/1/5 support, soldered on Atom based Pentium chip and at least one Intel based GbE port (with the option to stick another CT NIC in the PCI-e slot). Something tells me though that the newest celeron and pentium based atoms don't have support for 4 SATA 6Gbps ports though.
  • Gondalf - Tuesday, October 29, 2013 - link

    At least IMO, Calxeda is sandbagging a little about power consumption. A15 core is very power hungry, expecially over 1.6Ghz and Silvermont core has clearly showed a far lower power consumption under load.
    Dear Johan i can see a lot of marketing in Calxeda data, its pretty clear that this round is won by Intel with a wide margin.
    Maybe we need to wait some SPECpower submissions before any judgment. "Rough estimates" means nothing beacause Calxeda do not gives TDP data but only "average consumption" figures.
  • JohanAnandtech - Wednesday, October 30, 2013 - link

    Last time, Calxeda marketing was simply wrong about their servers being good memcached or CDN servers. But we found that their power numbers were pretty close to reality. So they deserve the benefit of the doubt...We won't know until we unleash our server workloads on real machine, of course.
  • Drumsticks - Tuesday, October 29, 2013 - link

    Does calxeda do any custom changes to the A15? Or do they just straight up use what arm effectively gives them?
  • JohanAnandtech - Wednesday, October 30, 2013 - link

    They do not alter the core AFAIK, most of the engineering goes to the uncore. And IMHO that is the right way to do it for a company like Calxeda
  • twotwotwo - Tuesday, October 29, 2013 - link

    The thing about the preannouncement of the A53/7 and Intel's roadmap is that it's always hard not to wonder how microservers based on the *next* uarch will do. :)
  • DARBYOTHRULL - Tuesday, October 29, 2013 - link

    My question is, where can you buy these processors? I wouldn't mind using one for a personal server.
  • JohanAnandtech - Wednesday, October 30, 2013 - link

    The problem is that the integrated fabric might be a bit too complicated (= expensive mobo) for your usage model. There are probably better solutions for you on the market.
  • DARBYOTHRULL - Wednesday, October 30, 2013 - link

    That is probably true, and thank you for your comment. If only I knew where to find them, it just seems difficult to build a custom Atom system.
  • chavv - Wednesday, October 30, 2013 - link

    What OS/apps are these server SOCs supposed to run on?

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