C4 Instances
C4 instances are ideal for compute-bound applications that benefit from high performance processors. C4 instances are well suited for the following applications:
Batch processing workloads
Media transcoding
High-traffic web servers, massively multiplayer online (MMO) gaming servers, and ad serving engines
High performance computing (HPC) and other compute-intensive applications
Hardware Specifications
C4 instances are based on custom 2.9 GHz Intel® Xeon® E5-2666 v3 (Haswell) processors,
optimized specifically for Amazon EC2. With Intel® Turbo Boost Technology, the processor clock
speed in C4 instances can reach as high as 3.5Ghz with 1 or 2 core Turbo Boost on
c4.8xlarge instances.
The following table highlights the feature set of the Intel® Xeon® E5-2666 v3 processor. For more information, see Intel and Amazon Web Services.

| Feature | Specification |
|---|---|
| Processor Number | E5-2666 v3 |
|
Intel® Smart Cache |
25 MiB |
|
Instruction Set |
64-bit |
|
Instruction Set Extensions |
AVX 2.0 |
|
Lithography |
22 nm |
|
Processor Base Frequency |
2.9 GHz |
|
Max All Core Turbo Frequency |
3.2 GHz |
|
Max Turbo Frequency |
3.5 GHz (available on |
|
Intel® Turbo Boost Technology |
2.0 |
|
Intel® vPro Technology |
Yes |
|
Intel® Hyper-Threading Technology |
Yes |
|
Intel® Virtualization Technology (VT-x) |
Yes |
|
Intel® Virtualization Technology for Directed I/O (VT-d) |
Yes |
|
Intel® VT-x with Extended Page Tables (EPT) |
Yes |
|
Intel® 64 |
Yes |
|
Idle States |
Yes |
|
Enhanced Intel SpeedStep® Technology |
Yes |
|
Thermal Monitoring Technologies |
Yes |
|
AES New Instructions |
Yes |
|
Secure Key |
Yes |
|
Execute Disable Bit |
Yes |
For more information about the hardware specifications for each Amazon EC2 instance type, see Amazon EC2 Instances.
C4 Instance Features
The following is a summary of the features for C4 instances:
C4 instances are EBS-optimized by default, and deliver dedicated block storage throughput to Amazon EBS ranging from 500 Mbps to 4,000 Mbps at no additional cost. EBS-optimized instances enable you to get consistently high performance for your EBS volumes by eliminating contention between Amazon EBS I/O and other network traffic from your C4 instance. For more information, see Amazon EBS–Optimized Instances.
You can enable enhanced networking capabilities. Enhanced networking provides significantly higher packet per second (PPS) performance, lower network jitter, and lower latencies. For more information, see Enabling Enhanced Networking on Linux Instances in a VPC.
You can cluster C4 instances in a placement group. Placement groups provide low latency and high-bandwidth connectivity between the instances within a single Availability Zone. For more information, see Placement Groups.
The
c4.8xlargeinstance type provides the ability to control processor C-states and P-states on Linux. C-states control the sleep levels that a core can enter when it is inactive, while P-states control the desired performance (in CPU frequency) from a core. For more information, see Processor State Control for Your EC2 Instance.
C4 Instance Requirements
The following are the requirements for C4 instances:
C4 instances require 64-bit HVM AMIs. They have high-memory (up to 60 GiB of RAM), and require a 64-bit operating system to take advantage of that capacity. HVM AMIs provide superior performance in comparison to paravirtual (PV) AMIs on high-memory instance types. In addition, you must use an HVM AMI to take advantage of enhanced networking.
You must launch your C4 instances into a virtual private cloud (VPC); they are not supported on the EC2-Classic platform. Amazon VPC enables you to launch AWS resources into a virtual network that you've defined. For more information about EC2-Classic and EC2-VPC, see Supported Platforms For more information about launching a VPC-only instance, see Instance Types Available Only in a VPC.
There is a limit on the total number of instances that you can launch in a region, and there are additional limits on some C4 instance types. For more information, see How many instances can I run in Amazon EC2?
If you need more C4 instances, you can request them using the Amazon EC2 Instance Request Form.
Support for 36 vCPUs
The c4.8xlarge instance type provides 36 vCPUs, which might cause
launch issues in some Linux operating systems that have a vCPU limit of 32.
We strongly recommend that you use the latest AMIs when you launch
c4.8xlarge instances.
The following Linux AMIs support launching c4.8xlarge instances
with 36 vCPUs:
Amazon Linux AMI 2016.03 (HVM)
Ubuntu Server 14.04 LTS (HVM)
Red Hat Enterprise Linux 7.1 (HVM)
SUSE Linux Enterprise Server 12 (HVM)
If you must use a different AMI for your application, and your c4.8xlarge
instance launch does not complete successfully (for example, if your instance status
changes to stopped during launch with a
Client.InstanceInitiatedShutdown state transition reason), modify your
instance as described in the following procedure to support more than 32 vCPUs so that you
can use the c4.8xlarge instance type.
To update an instance to support more than 32 vCPUs
Launch a C4 instance using your AMI, choosing any C4 instance type other than
c4.8xlarge.Update the kernel to the latest version by following your operating system-specific instructions. For example, for RHEL 6, use the sudo yum update -y kernel command.
Stop the instance.
(Optional) Create an AMI from the instance that you can use to launch any additional
c4.8xlargeinstances that you need in the future.Change the instance type of your stopped instance to
c4.8xlarge(choose Actions, select Instance Settings, choose Change Instance Type, and then follow the directions).Start the instance. If the instance launches properly, you are done. If the instance still does not boot properly, proceed to the next step.
(Optional) If the instance still does not boot properly, the kernel on your instance may not support more than 32 vCPUs. However, you may be able to boot the instance if you limit the vCPUs.
Change the instance type of your stopped instance to any C4 instance type other than
c4.8xlarge(choose Actions, select Instance Settings, choose Change Instance Type, and then follow the directions).Add the
maxcpus=32option to your boot kernel parameters by following your operating system-specific instructions. For example, for RHEL 6, edit the/boot/grub/menu.lstfile and add the following option to the most recent and activekernelentry:default=0 timeout=1 splashimage=(hd0,0)/boot/grub/splash.xpm.gz hiddenmenu title Red Hat Enterprise Linux Server (2.6.32-504.3.3.el6.x86_64) root (hd0,0) kernel /boot/vmlinuz-2.6.32-504.3.3.el6.x86_64maxcpus=32console=ttyS0 ro root=UUID=9996863e-b964-47d3-a33b-3920974fdbd9 rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 xen_blkfront.sda_is_xvda=1 console=ttyS0,115200n8 console=tty0 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_NO_LVM rd_NO_DM initrd /boot/initramfs-2.6.32-504.3.3.el6.x86_64.imgStop the instance.
(Optional) Create an AMI from the instance that you can use to launch any additional
c4.8xlargeinstances that you need in the future.Change the instance type of your stopped instance to
c4.8xlarge(choose Actions, select Instance Settings, choose Change Instance Type, and then follow the directions).Start the instance.

