What is a “Server-Class” SOC?

As reported in various outlets yesterday, Intel has released their S1200 line of Atom SOC’s targeting the microserver market with the tagline: “Intel Delivers the World’s First 6-Watt Server-Class Processor”. The first notable point here is that they had to use 6 Watts, because 5 was already taken. The second notable point is their definition of “Server-Class”. Looking at the list of features on the Atom S1200, there are key “Server-Class” features missing:

  • Networking: Intel’s SOC requires you to add hardware for networking
  • Storage: Once again, there is no SATA connectivity included on the Intel SOC, so you must add hardware for that
  • Management: Even microservers need remote manageability features, so again with Intel you need to tack that on to the power and price budgets.

Unless you add additional hardware on top of it, Intel’s SOC allows you to boot and not much else. Let’s also consider the fact that you’ve got a total of 8 lanes of PCI Express Gen 2 on each SOC. If you’d like to add the Server-Class items listed above, choose wisely, because those 8 lanes will go fast. Add all of that hardware, plus memory, and 6 W is simply not possible.  And of course these additional components add cost and take space as well.

Let’s expand that thought to an actual Atom S1200 powered system, like the Quanta S900- X31A. Each node includes a Marvell 88SE9130 SATA controller at a TDP of 1W, an Intel i350 1GB controller at 2.8W TDP, an AST2300M estimated at a conservative 1W, and an SODIMM at roughly 1.2W (Using the same number we at Calxeda have used). That adds at least 6 more watts per node, almost doubling the 6.1W TDP of the processor. Multiply that across 48 nodes and you just tacked on 288W to each chassis. In a 42U rack full of them, you just added 4kW to each rack! By no means is that a limitation or shortcoming of the Quanta design, which is actually quite good, but rather an indication of the excess baggage that all vendors will need to deal with in putting together an S1200 powered system.

The currently shipping Calxeda ECX-1000 Server-Class SOC ships with SATA, Ethernet fabric links, IPMI-based management, and 8 lanes of PCI Express Gen 2, standard at 3.8W (5W including 4GB DDR3). It’s also worth pointing out that Calxeda’s integrated fabric switch provides more than just the Ethernet ports missing on the Atom S1200.  Applied at the system and rack level, it can dramatically reduce Top of Rack Switch ports and cabling complexity, while increasing internode bandwidth by 10-fold.  You can have all of that in a 5W server. Not 5W + additional components. Why not take that 12W budget you need for each S1200 node and get two Calxeda nodes with all of the Server-Class features included?

In the end, Intel may simply be claiming 64-bit as the main benchmark for Server-Class. When matching microservers to the appropriate workloads, we’ve found that there is surely a place for 32-bit in the datacenter. We’ll be providing a blog post on that very topic in the near future.


  1. You forgot to mention cost. What is the added cost of all these additional components needed to build an equivalent Calxeda system?!

    • Steve Croce says:

      You raise a good question. All of those additional components will add cost to the Atom solution, but by integrating them on the die with our SOC, we’ll be able to remove many of the costs associated with adding discrete motherboard components. The result is that, in general, Calxeda is able to deliver a more cost-effective solution that consumes less power with the same (or better) feature set. Naturally, your price will vary based on volume, but the higher level integration should allow Calxeda’s partners to price very competitively against Atom S1200.


  1. […] What is a “Server-Class” SOC? [‘ARM Servers Now’ blog from Calxeda, Dec 12, 2012] […]

  2. […] is rightfully annoyed by these claims and put up a blog about it. Marvell seem to simply not understand the press, so we have no idea what they think, but you can […]

  3. […] there are a number of Intel competitive posts on Calxeda’s ‘ARM Servers, Now!’ blog:- What is a “Server-Class” SOC? [Dec 12, 2012]- Comparing Calxeda ECX1000 to Intel’s new S1200 Centerton chip [Dec 11, 2012]which […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: