Nehalem-EP: Your Best Consolidation Option?April 21, 2009
Intel’s Nehalem is new and sexy, but currently limited to 2P platforms. This fact is forcing Intel to refer customers to their aging Xeon 7400 series (based on the older “Core” architecture, not Nehalem) for 4P solutions and those seeking higher consolidation ratios. Still, leading equipment and solution vendors are scrambling to build offerings around the 2P-only Nehalem due to its significant value proposition over aging, dead-end Intel technology that can not keep-up in an increasingly virtualized world.
Intel asks you to “replace nine (single-core) servers” with one 2P Nehalem system and promises to “deliver ROI in 8-months” based on power savings alone. This “enhanced value proposition” is a compelling component of a solution providers’ foot-in-the-door strategy to lay-out system, storage and virtualization refreshes. The goal: higher consolidation rates and better virtualized performance promised by Nehalem (better results can be achieved with AMD Shanghai – see below). But with no 4P or 8P offerings is Nehalem the only option? Better yet, is it even a cost effective “refresh” option?
To understand the value proposition of Nehalem in an increasingly virtualized world, we need to identify the key benefits of the technology and how a single 2P system can replace 9 2P/1C systems. Simply put, Nehalem represents the most current virtualization hardware offering from Intel, finally bringing it to parity with AMD’s quad-core offering which has proved itself over the last 18-months. Its updated quad-cores, IPC, bus architecture and hardware assisted virtualization technologies deliver capabilities that older single-core systems can not match.
EPT and RVI – Hardware Virtualization Enhancements
AMD introduced its hardware assisted virtualization in 2006 with AMD-V (code named Pacifica) available in all processors supporting Socket-F and AM2 platforms (except the low-end Semperon). This technology enabled Xen-based hypervisors – lacking broad binary translation engines – to virtualize operating systems without modification. Intel later countered lead with Intel VT-x in its Itanium and Pentium D 662/672 desktop processors in 2005. Intel added VT-x capability to Xeon processors in 2H/2006. Intel makes VT-x available in some Core and Core2 processors, Xeon 3000/5000/7000 and Core i7 processors. No Celeron, Pentium Dual-Core (prior to 662) or Pentium M processors have this feature.
While AMD-V and Intel VT-x provided Xen with the tools to make closed source operating systems like Windows hypervisor friendly, like binary translation these technologies provided little to accelerate virtualization. For the most part, hypervisors had to managed complex context switching in software which created significant performance differences between virtualized and bare-metal platforms.
In 2007, AMD followed-up with Rapid Virtualization Indexing (RVI) in its 65nm Barcelona quad-core and vastly improved this technology with the release of the 45nm Shanghai quad-core in early 2008. With RVI support in VMware, Xen and Hyper-V, the processor intensive “book keeping” associated with context switches is offloaded to hardware translation look-aside buffers (TLB) with significant performance gains in virtualized environments. This technology effectively closes the gap between hypervisor and bare-metal performance, increasing consolidation ratios and enabling nearly 100% of workloads to be virtualized.
With the launch of the Core i7 in Q4/2008 Intel introduced its analog to AMD’s RVI: Intel’s Enhanced Page Table or EPT. Nehalem borrows this technology from Core i7 to deliver 2-processor (2P) solutions supporting EPT and ECC, suitable for virtualization systems. The combination of improved IPC (over Core and earlier micro architectures), addition of QPI for bus and memory access (similar to AMD’s HyperTransport) and EPT bring Nehalem into parity with AMD’s Shanghai Opteron.
Rip-Up and Re-Try?
There are no “drop-in” upgrades available to Intel customers: Nehalem is rip-up-and-retry only. Furthermore, the inclusion of Nehalem into a virtualization eco-system would imply that “performance sensitive” applications be bound to 2P systems. However, Intel still refers to the older, front side bus “Dunnington” 6-core processor as its best option for virtualization and consolidation. Why? Systems based on 4P platforms provide better consolidation ratios and scalability than 2P platforms.
However, for AMD customers, any server system made in the last 3-years that is based on the Socket-F platform can take advantage of RVI today with Shanghai and very soon with Istanbul. This option provides a consistent refresh across not only 2P systems, but all the way through 8P systems, and with significant savings over Nehalem.
If Nehalem Replacement Yields ROI in 8-months, Shanghai Refresh Delivers ROI in 2-months
The cheapest 2P Nehalem system (2P, 2.66GHz and 32GB of RAM) weighs-in at $5,436 according to Dell on-line. Intel’s marketing campaign indicates this will be paid for by power savings over 8-months when replacing “nine, dual processor, single-core (Intel) systems.” But what if your virtualization infrastructure is AMD-based?
An AMD socket-F refresh incorporating two 2.6GHz Shanghai processors and 16GB of RAM (assuming existing dual-core and 16GB memory) weighs-in at $1,346 – a 75% CAPEX savings over Nehalem system replacement – and delivers comparable power savings. This results in a 2-month ROI using Intel’s math and requires no fork-lift or waste disposal charges.
If Nehalem Replacement Yeilds ROI in 8-months, Istanbul Replacement Delivers ROI in 4-months
Assuming Istanbul delivers at Shanghai’s cost plus 50% (per processor), a Nehalem-equivalent Dell 2P Istanbul system will weigh-in at just under $4,400 (estimated). This leads to a 50% increase in capacity over Nehalem 2P (Istanbul’s 12-cores vs. Nehalem’s 8-cores) and subsequently delivers ROI in just over 4-months (based on Intel’s math). It also results in fewer servers, potentially accelerating ROI even further. Better still, Istanbul will drop into 2P, 4P and 8P systems allowing the enterprise to refresh all aspects of its infrastructure – not just the 2P segment.
Istanbul: Refresh ROI in Less Than 2-months
An Istanbul refresh incorporating two 2.6GHz processors and 16GB of RAM (assuming existing dual-core and 16GB memory) could weigh-in at $1,846 (estimate)- a 75% 66% CAPEX savings over Nehalem system replacement – and delivers comparable power savings while delivering 50% more capacity. This results in an ROI of 1.6 months using Intel’s math and requires no fork-lift or waste disposal charges given existing Socket-F systems in the infrastructure.
If a Nehalem proposition works for your company’s revenue model, ask your system integrator about a Shanghai (and later Istanbul) alternative. This pits proven technology – at equivalent performance and feature levels – against early adoption hardware with unknown failure modes or compatibility issues. Given ROI wins for both Shanghai and Istanbul in replacement and refresh, AMD appears to feed the bottom line while offering significant performance and upgrade benefits.
Nehalem represents a good choice in the modern virtualization marketplace. However, only when Nehalem is available in 4P and 8P systems will it offer a complete solution for enterprise computing. When that time comes, AMD’s Istanbul needs to have several months of successful refreshes in its favor to maintain AMD’s value proposition against Nehalem.