How to find out AES-NI (Advanced Encryption) Enabled on Linux System


The Intel Advanced Encryption Standard (AES) or New Instructions (AES-NI) engine enables high-speed hardware encryption and decryption for OpenSSL, ssh, VPN, Linux/Unix/OSX full disk encryption and more. How do I check support for Intel or AMD AES-NI loaded in my running Linux in my Linux based system including OpenSSL?

he Advanced Encryption Standard Instruction Set and the Intel Advanced Encryption Standard New Instructions allows specific Intel/AMD and other CPUs to do extremely fast hardware encryption and decryption.

Please note that the AES-NI support is automatically enabled if the detected processor is among the supported list as above. For a list of processors that support the AES-NI engine, see Intel ARK/AMD/ARM (vendor)/VIA padlock site and documentation. The AES-NI is an extension to the x86 instruction set architecture for microprocessors from Intel and AMD. It increases the speed of apps performing encryption and decryption using the AES. Several server and laptop vendors have shipped BIOS configurations with the AES-NI extension disabled. This page shows you how to check that your CPU supports AES-NI on Linux. You may need a BIOS update to enable AES/AES-NI or change the BIOS settings. The following CPUs are supported:

  1. Intel Westmere/Westmere-EP (Xeon 56xx)/Clarkdale (except Core i3, Pentium and Celeron)/Arrandale(except Celeron, Pentium, Core i3, Core i5-4XXM).
  2. Intel Sandy Bridge cpus (except Pentium, Celeron, Core i3).
  3. Intel mobile Core i7 and Core i5.
  4. Intel Ivy Bridge processors All i5, i7, Xeon and i3-2115C only.
  5. Intel Haswell processors (all except i3-4000m, Pentium and Celeron).
  6. Intel Coffee Lake/Kaby Lake and so on
  7. AMD Bulldozer/Piledriver/Steamroller/Jaguar/Puma/Ryzen-based processors.
  8. AMD Geode LX processors.
  9. VIA PadLock (a different instruction set than Intel AES-NI but does the same thing at the end of the day).
  10. ARM – selected Allwinner and Broadcom using security processor. There are few more ARM based processor.

How to find out AES-NI (Advanced Encryption) Enabled on Linux System

One can find out that the processor has the AES/AES-NI instruction set using the lscpu command:


Type the following command to make sure that the processor has the AES instruction set and enabled in the BIOS:

grep -o aes /proc/cpuinfo


grep -m1 -o aes /proc/cpuinfo

Sample outputs:

Sample output LSCPU
Sample output /proc/cpuinfo

The aes output indicates that I have the AES-NI support enabled by Linux.

Check if AES-NI is enabled on Linux with cpuid

Another option is to use the cpuid command:

cpuid | grep -i aes | sort | uniq

Sample outputs:

 AES instruction                         = true

How do I verify that all my CPU supports AES NI?

The output of the following two commands should be same:

lscpu | grep '^CPU(s):'


grep -o aes /proc/cpuinfo | wc -l

Is Intel AES-NI instructions optimized driver loaded for my Linux server/laptop/desktop?

Type the following command to check for AES-NI support on your processor:

sort -u /proc/crypto | grep module

Sample outputs:

module       : aesni_intel
module       : aes_x86_64
module       : crc32_pclmul
module       : crct10dif_pclmul
module       : ghash_clmulni_intel
module       : kernel

Is Intel AES-NI enabled for openssl enabled?

Now that we have verified support, it’s time to test it. Is my AES-NI/VIA padlock engine supported?

openssl engine

Sample outputs from VIA based cpu that supports the AES:

(padlock) VIA PadLock (no-RNG, no-ACE)
(dynamic) Dynamic engine loading support

Another output from Intel based system that support the AES-NI:

openssl engine
(aesni) Intel AES-NI engine
(dynamic) Dynamic engine loading support

Test: AES-NI CPU vs Normal CPU without the AES-NI/Packlock support

In this example, serverA has the AES-NI and serverB has no support for hardware encryption:

dd if=/dev/zero count=1000 bs=1M | ssh -l vivek -c aes128-cbc serverA "cat >/dev/null"
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 10.6691 s, 98.3 MB/s


dd if=/dev/zero count=1000 bs=1M | ssh -l vivek -c aes128-cbc serverB "cat >/dev/null"
vivek@localhost's password:
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 31.6675 s, 33.1 MB/s

Test: For the benchmark my openssl performance?

Again run the following commands on both the systems:

openssl speed


openssl speed aes-128-cbc

For latest version of openssl, try the following two commands (the 2nd command should have higher

openssl speed aes-256-cbc
openssl speed -evp aes-256-cbc

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