you can boot a knoppix to perform those benchmarks or my debian 8 based ideal-linux-usb-stick image.

BE CAREFUL WITH KNOPPIX ON SYSTEMS WITH NTFS AND LSI RAID ADAPTERS!!! (you might lose your partition table)

apt-get install sysbench; # install it
sysbench --test=cpu --cpu-max-prime=20000 run; # run it
sysbench 0.4.12: multi-threaded system evaluation benchmark
Running the test with following options:
 Number of threads: 1
Doing CPU performance benchmark
Threads started!
 Done.
Maximum prime number checked in CPU test: 20000
 Test execution summary:
 total time: 29.8547s
 total number of events: 10000
 total time taken by event execution: 29.8524
 per-request statistics:
 min: 2.90ms
 avg: 2.99ms
 max: 6.04ms
 approx. 95 percentile: 3.31ms
Threads fairness:
 events (avg/stddev): 10000.0000/0.00
 execution time (avg/stddev): 29.8524/0.00

script it:

per default it uses only one core – to use automatically all cores

vim /scripts/bench_cpu.sh

#!/bin/bash

NUM_CORES=$(grep -c ^processor /proc/cpuinfo)

echo "============ CPU MIPS and FLOPS"

cat /proc/cpuinfo | grep -ie hardware;
cat /proc/cpuinfo | grep -ie model;
cat /proc/cpuinfo | grep -ie mips;
cat /proc/cpuinfo | grep -ie flops;
echo "============ CPU BENCHMARK"

sysbench --test=cpu --cpu-max-prime=20000 run --num-threads=$NUM_CORES

or download it from here. bench_cpu.sh

:wq save and quit

wget http://dwaves.de/wp-content/uploads/2017/05/bench_cpu.sh_.txt; # download script
mv bench_cpu.sh_.txt bench_cpu.sh; # rename
chmod +x /scripts/bench_cpu.sh; # make script executable
/scripts/bench_cpu.sh; # run it

CPU Benchmarks example results:

CPU Blowfish
CPU Blowfish
This Machine 2253 MHz 5.037
Intel(R) Celeron(R) M processor 1.50GHz (null) 26.1876862
PowerPC 740/750 (280.00MHz) (null) 172.816713
CPU CryptoHash
CPU CryptoHash
This Machine 2253 MHz 286.729
CPU Fibonacci
CPU Fibonacci
This Machine 2253 MHz 1.806
Intel(R) Celeron(R) M processor 1.50GHz (null) 8.1375674
PowerPC 740/750 (280.00MHz) (null) 58.07682
CPU N-Queens
CPU N-Queens
This Machine 2253 MHz 5.500
FPU FFT
FPU FFT
This Machine 2253 MHz 0.908
FPU Raytracing
FPU Raytracing
This Machine 2253 MHz 19.235
Intel(R) Celeron(R) M processor 1.50GHz (null) 40.8816714
PowerPC 740/750 (280.00MHz) (null) 161.312647
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