Redis vs Memcache vs Memcached

July 18, 2012 • 9 minutes read

I decided to test the performance of two popular cache servers. This is Redis and Memcached. I used phpredis, Memcache and Memcached.

Hardware

I decided to test them on two different PCs for the better results reliability

PC №1:

PC №2:

Tests

Below you can see the script that I wrote for the tests

$records = 100000;
$redis = new Redis();
$redis->connect('localhost', 6379);
$memcache = new Memcache();
$memcache->addServer('localhost');
$memcached = new Memcached();
$memcached->addServer('localhost', 11211);
$startRedis = microtime(true);
for($i=0; $i<$records; $i++)
{
    $value = sha1(mt_rand(10000,20000));
    $redis->set($i, $value);
}
$endRedis = microtime(true) - $startRedis;
$startMemcache = microtime(true);
for($i=0; $i<$records; $i++)
{
    $value = sha1(mt_rand(10000,20000));
    $memcache->set($i, $value);
}
$endMemcache = microtime(true) - $startMemcache;
$startMemcached = microtime(true);
for($i=0; $i<$records; $i++)
{
    $value = sha1(mt_rand(10000,20000));
    $memcached->set($i, $value);
}
$endMemcached = microtime(true) - $startMemcached;
echo 'Redis: '.$endRedis."\r\n";
echo 'Memcache: '.$endMemcache."\r\n";
echo 'Memcached: '.$endMemcached."\r\n";

Script has been changed for multi sets:

$records = 100000;
$redis = new Redis();
$redis->connect('127.0.0.1', 6379);
$memcached = new Memcached();
$memcached->addServer('127.0.0.1', 11211);
$array = array();
for($i=0; $i<$records; $i++)
{
    $value = sha1(mt_rand(10000,20000));
    $key = "key".$i;
    $array[$key] = $value;
    $arrayKeys[] = $key;
}
//multi set
$startRedis = microtime(true);
$redis->mset($array);
$endRedis = microtime(true) - $startRedis;
$startMemcached = microtime(true);
$memcached->setMulti($array);
$endMemcached = microtime(true) - $startMemcached;
echo 'Redis multi set: '.$endRedis."\r\n";
echo 'Memcached multi set: '.$endMemcached."\r\n";
//multi get
$startRedis = microtime(true);
$result = $redis->mget($arrayKeys);
$endRedis = microtime(true) - $startRedis;
$startMemcached = microtime(true);
$result = $memcached->getMulti($arrayKeys);
$endMemcached = microtime(true) - $startMemcached;
echo 'Redis multi get: '.$endRedis."\r\n";
echo 'Memcached multi get: '.$endMemcached."\r\n";

Test results:

Results for PC №1:

Results for PC №2:

Conclusions

• the performance and capabilities of Memcache are poor in comparison with Redis and Memcached. I think we can safely reject it
• in operations with sets Redis exceed Memcached
• in operations with gets Redis loses to Memcached
• Redis is significantly worse to Memcached with multi gets at high volumes that more than 100000. I think you should not use the multi gets in Redis with such volumes
• the results for a Redis and Memcached are similar on multi gets for small volumes, like 1000 or 100 entries
• despite the superiority of Memcached, in some cases, I still choose the Redis because of its broader functional and convenient features