On Tuesday, Intel introduced the server variant of their Atom processor. Formerly known under the codename Centerton, it will now be advertised as Atom S1200 series and is available immediately from launch and the company reportedly has 20 design wins.
From a technical standpoint, the launch is not very exciting. Unlike other Atom SKUs aimed at consumer products, Intel simply enabled all of the capabilities that laid dormant in the silicon. Namely 64-bit technology and hardware-assisted virtualization, both of which were part of the Atom architecture from the start but disabled on most SKUs, in addition to that Centerton supports ECC memory up to 8GB. It is unknown whether ECC support was technically present in other Atom memory controllers, but given that Intel has a lot of experience with memory controllers, it probably was not hard to add.
| Model | Clock | TDP | Price |
| Atom S1260 | 2.0 GHz | 8.1 W | $64 |
| Atom S1240 | 1.6 GHz | 6.1 W | $64 |
| Atom S1220 | 1.6 GHz | 8.1 W | $54 |
The Atom S1200 models are dual-core chips featuring Hyper-Threading, thus four CPUs will be exposed to the operating system. The chip features 1MB of L2 cache (512KB per core). The integrated memory controller only supports a single channel and can function up to DDR3-1333 with standard voltage (1.5V) modules and up to DDR3-1066 with low voltage (1.35V) SO-DIMMs. As the table shows, the main differentiation is clock speed, TDP and price. The S1240 can be considered a low-voltage version of the S1220 and thus comes in at a price premium.
While the company keeps citing the 6W number over and over, the CPUs in this new range of products actually span over a TDP range starting at 6.1W up to 8.5W. Given that Centerton is actually a SoC integrating the I/O and chipset functionality, this is still impressive considering that even the chipsets for the entry level Xeon series are specced at TDPs in excess of 6W (e.g. the C216 chipset is specced at 6.7W TDP). Of course we are talking about a richer feature-set in the case of the Xeon chipsets.
Speaking of I/O features, the Atom S1200 integrates 8 lanes of PCIe 2.0 over as many as four controllers as well as SPI, UART, LPC and GPIO interfaces, that traditionally sit in the chipset. However, there is no SATA, USB, or Ethernet functionality integrated into the chip. Servers that need such interfaces need to be extended with additional chips.
Intel sees the applications of this new product in microservers (e.g. web hosting), communications (e.g. basic L2 switching), and low end storage solutions. In a webcast presentation Intel?s Diane Bryant boasted that one of their 20 design wins is even a conversion of a former ARM product line. She also stressed that up until now there was no such thing as an ARM-based enterprise server, pointing out that the essential features in this space are reliability, 64-bit, and virtualization. That is not to say the company doesn’t acknowledge the developments and investments going on in this space, but for now Intel believes itself the leader of the pack. So much about Intel not feeling threatened by the architecture from a certain British IP licensing company.
Intel is actually quite open about the strengths of their various products. While the Atom S1200 series allows up to 5x more dedicated nodes per rack (that is VM instances with at least 1 virtual core), a rack full of Xeon E3 1265v2 will deliver twice as many transactions per minute. An HP representative later explained that in the right workloads, Atom S1200 delivers more than double the performance per watt compared to low-voltage Xeon E3 processors. At the same time, in computation-intensive apps, the Xeon E3 enjoys a similar 2x performance per watt advantage.
Given that example, Intel would make $32.9k in CPU revenues in the case of the Xeon-based server and about $35.8k on the Atoms. These numbers are based on a full rack filled with systems. However, this excludes chipset revenues, that are working in Xeons favor. The key takeaway point is that Intel in the end doesn’t care which chip it sells; the company knows that in the respective target segments of Atom, higher volumes offset the lower per chip revenues. That doesn’t even factor in the considerable difference in die size, which also affects profitability.
At the end of the presentation, a roadmap outlining future plans was shown. In 2013 Intel aims to replace Centerton with a new 22nm chip called Avoton. Avoton will feature a much improved out-of-order execution core and also integrate fabric technology. It was raised during the call that the line between Atom SoC CPUs and low power Xeon CPUs will blur a bit performance-wise. Intel pointed out that they are committed to both product lines. While the roadmap already shows a 14nm follow-up to Avoton for 2014 or later, at this point Intel remains tight-lipped about the future beyond 22nm.
