I am trying to improve the load speed of my Magento store http://www.jinkou.info the load time for the front page on pin开发者_开发百科gdom tools is 13 seconds! It seems that the delay in the pingdom readout is the green section after "connect"

What is likely to be causing this bottleneck?

First of all, you need to make sure that Magento cache is enabled. You can do it in Admin -> System -> Cache Management. All cache data should be enabled there.

If it didn't help, you need to enable Profiler, and this will help you to see bottlenecks as a table in the footer. You can do it in 2 steps:

1. Go to Admin -> System -> Configuration -> Developer -> Debug, and enable Profiler.

2. Edit Magento's index.php file, and uncomment this line:

   Varien_Profiler::enable();

After steps 1 and 2 has been done -- go to any page, a look at the footer.

Magento certainly does like to use the database a lot and every query means a roundtrip to the disc while nothing else is being done. Make sure MySQL has query cache turned on and has lots of memory assigned to it, for large sites several gigabytes are needed. This is why a dedicated server is best.

From tests I find that the biggest CPU cost is running PHP. Even when using an opcode cache it is still an interpreted language and that is expensive. Run PHP as a separate FastCGI process. If following the traditional three-tier approach this would also be a dedicated server.

Only use Memcache if you have more than one PHP server, otherwise just mount var/cache/ as tmpfs.

Lastly as rpSetzer has said - and no doubt others will say - use block caching.
More block caching.
Page caching.

Hard to say, here are a few tips that can certainly help:

• use APC
• use Memcache for caching
• make use of block caching

Magento caching must be enabled when the site gets loaded. But what really makes a difference is a PHP cache. We use APC and its a major difference. Also make sure to tune your database! MySQL tuning makes a uge improvement. Google for MySQL tuning and you will find.

with the help of magento speed analyzer module you can able to find each block load time.

with the help of speed analyzer module you can able to find each block load time. http://www.magentocommerce.com/magento-connect/speed-analyzer.html