The Power of Intel E5 Processors
When you’re looking for a virtual server provider, critical infrastructure such as RAM, disk space, transfer quota, and CPU cores have to be considered and compared.
In this blog post, I’ll focus on the CPU power of a virtual private server.
What Do You Get?
Different plans with differing prices typically have different amounts of CPU cores. Your need for a virtual server will help determine how many cores you should acquire with a plan.
If you’re already using a virtual server, you can run commands to find out what kind of processor is running, although this isn’t always guaranteed by the provider. You can usually find this information stored in the /proc/cpuinfo file.
More Cores Aren’t Always Better
Not all CPU cores are created equal. In many instances, a single, stronger core can outperform two weaker cores.
Several years ago, Linode offered 8 CPU cores with each plan. Sounds pretty crazy, right? For $20 a month, you got 8 CPU cores. When Linode upgraded that 1GB plan to a 2GB plan, CPU cores reduced to two.
Many users were skeptical of this supposed downgrade, but after taking the upgrade and running the benchmarks, they found that their CPU power increased. Why was that?
At the time of this upgrade (March 2014), Linode had finished deploying a newer generation of processors in all of its servers. These new plans, albeit now with fewer CPU cores, were running stronger processors.
Before the 2014 upgrade, one of the more common processors Linode’s cloud fleet ran was the Intel Xeon L5520. After the upgrade, our fleet was using the Intel Xeon E5–2670. Cpubenchmark.net showed a CPU Mark score of 4,377 for the L5520 jump to 12,479 for the E5 — that’s nearly a three-fold increase!
For the large percentage of users whose processing rarely maxed out even one L5520, getting the immense performance of a new E5–2670 more than satisfied their CPU needs.
Before the 2014 upgrade, many Linode users hardly ever used one full core, let alone eight. That much CPU power was pretty much overkill for a basic web server and database.
If you were running an application that was specifically threaded to run across multiple cores at once, you would start to see better performance from additional CPU cores. With this being relatively uncommon, the large percentage of users not exceeding one CPU core of a L5520 saw a huge increase when moving to a E5–2670.
Furthermore, decreasing the amount of cores available on our less expensive plans helped prevent abuse of our systems. When eight cores were the standard, a user could sign up for our low cost service, hammer away on all eight cores, and cause more steal and CPU contention for other customers on the same host.
After the 2014 upgrade, CPU steal issues were pretty much eliminated. Everyone regained full access to the cores they deserved.
What is ECU and GCEU?
When looking at other popular cloud hosts, AWS identifies its processor power as ECU, rather than with a name or model number. Likewise, Google Compute Engine lists its processor power as GCEU. What do each of these units mean?
The given definition of an Amazon ECU (EC2 Compute Unit) is that 1 ECU equals the compute power of a 1.0–1.2GHz 2007 server CPU. This proprietary processing power measure is very tough to compare directly since no Intel Xeon has been clocked in the 1.0–1.2GHz range since the Pentium III-based Xeons in 2000.
Regardless, lets choose the processor with the slowest clock speed in 2007 and use that as a conservative example. The Intel Xeon E5405 came out in Q4 2007 and clocked in at 2GHz with a CPU Mark of 2,908. For our comparisons, we’ll consider that 1 ECU equals 2,908 CPU Mark benchmark score.
The given definition of GCEU (Google Compute Engine Unit) is that 2.75 GCEUs represent the minimum power of one virtual CPU — hardware hyper-thread — on the Sandy Bridge, Ivy Bridge, and Haswell processor platforms. The first Sandy Bridge Xeon to be released was the Xeon E3–1220L, rated with a CPU Mark score of 3,563. With this in mind, we can approximate that 1 GCEU equals 1,296 CPU Mark benchmark score.
Compare the ECU and GCEU to a Xeon E5–2680v3
Little more than two years after the upgrade, most of Linode’s servers are now equipped with the E5–2680v3 processor, which sports a CPU Mark score of 18,890 — another 50-percent performance jump from the previous upgrade.
A single E5–2680v3 core on our smallest plan would give one of our cloud hosts an approximate ECU of 6.5. Amazon’s general EC2 plans don’t reach 6.5 ECU until their m4.large plan. Smaller AWS plans list available ECU as “variable,” a vague term that leaves you suspecting just how much CPU power is available.
Compared to GCEU, a single E5–2680v3 core would equate to approximately 14.5 GCEU. This level of processing power falls roughly between the n1-standard-4 and n1-standard-8 plans on Google Compute Engine, which have 4 and 8 CPU cores respectively, while the E5–2680v3 on Linode requires just one core to approach this power.
Choose Quality and Performance
CPU power is essential to an optimally performing cloud server. Without clearly defined specs, you won’t know just how much performance your host can supply. Choose wisely.
When you’re evaluating your next cloud host and discover that its server fleet is powered by the Intel Xeon E5 family processors, you know you will be gaining control of quality operation and optimal performance. You can expect to find the powerful Intel Xeon E5 processors equipped in all of Linode’s servers.
If you have any questions or comments about Linode’s use of E5 processors, feel free to tweet us, @Linode, or contact our 24/7 support: http://linode.com/support.
