Amazon AWS EC2 C5 Instances with Custom Intel Xeon Scalable CPUs

Amazon AWS EC2
Amazon AWS EC2

In what may be the least surprising release this year, Amazon AWS EC2 now supports Intel Xeon Scalable CPUs with a new generation of C5 instances. Amazon AWS is certainly considered one of the major consumers of server infrastructure so it is little surprise to see that they are not using an off-the-shelf CPU. We know Intel does customizations for its largest customers and disables IP blocks/ alters features for retail CPUs. This is the latest example of that trend.

New Amazon AWS EC2 C5 Instances

Here are the quick specs on the new instance types including pricing.

Model vCPU Memory (GiB) Storage EBS Bandwidth $/hour
(US East)
c5.large 2 4 EBS Optimized Up to 2,250 Mbps 0.085
c5.xlarge 4 8 EBS Optmized Up to 2,250 Mbps 0.17
c5.2xlarge 8 16 EBS Optimized Up to 2,250 Mbps 0.34
c5.4xlarge 16 32 EBS Optimized 2,250 Mbps 0.68
c5.9xlarge 36 72 EBS Optimized 4,500 Mbps 1.53
c5.18xlarge 72 144 EBS Optimized 9,000 Mbps 3.06


Amazon AWS EC2 C5 instances are powered by 3.0GHz CPUs with a max single core turbo boost of 3.5GHz. At the time of this writing, Intel has three listed CPUs with that base clock, the Intel Xeon Platinum 8158, the Gold 6154 and Gold 6136. All three CPUs have a 3.7GHz max turbo frequency. Intel and Amazon did not comment on the model number as they have done with previous generations.

What AWS and Intel did discuss was the fact that the new instances have more memory, more vCPUs and more memory to vCPUs than the previous generation C5 instances. AWS also touts that customers can use the new AVX-512 instruction set for 2x the FLOPS per cycle. This makes us believe that they are using dual port FMA AVX-512 as found on the Intel Xeon Platinum and Gold 6100 series.

If you want to read more about the AWS C5 compute instance type you can read more here. Overall new instance types are a good thing but we now see Amazon having to do something that on-prem IT admins have done for decades, differentiating features based on hardware generation even for simple compute nodes.


  1. The cpuinfo output of the C5 machines is as follows:

    processor : 0
    vendor_id : GenuineIntel
    cpu family : 6
    model : 85
    model name : Intel(R) Xeon(R) Platinum 8124M CPU @ 3.00GHz
    stepping : 3
    microcode : 0x100013a
    cpu MHz : 3000.000
    cache size : 25344 KB
    physical id : 0
    siblings : 2
    core id : 0
    cpu cores : 1
    apicid : 0
    initial apicid : 0
    fpu : yes
    fpu_exception : yes
    cpuid level : 13
    wp : yes
    flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm mpx avx512f rdseed adx smap clflushopt clwb avx512cd xsaveopt xsavec xgetbv1 ida arat
    bugs :
    bogomips : 6000.00
    clflush size : 64
    cache_alignment : 64
    address sizes : 46 bits physical, 48 bits virtual
    power management:

    Three noteworthy features of the C5 instance types:
    – ENA (Elastic Network Adapter) is mandatory
    – OS needs to have NVMe drivers
    – Instance creation is instantaneous with supported AMIs


Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.