Hi,
you think your server is performing poorly and you want to improve the output speed of Joomla. This article should give you some things to check and solve to sometimes drastically enhance your servers performance. Lets make a list:

General Optimizations:

• Hosting package
• HTML code
• Images
• PHP accelerators

Joomla specific Optimizations

• Used extensions
• Database
• Debugging your site
• SEF/SEO

General Optimizations:
Hosting package
A lot of people out there buy a shared hosting package and expect to be able to run a site with hundreds of hits per second on that one. We have to make it clear here, that Joomla is not static HTML. You may be able to service hundreds, if not thousands of users per second with static HTML pages, but Joomla needs quite some CPU power and if you plan a site with more than about 5 hits per second, you should directly look for a dedicated server, even more hits, and you should think about a load balancing system, several servers and a MySQL cluster. There is an interesting thread on this one here. For a normal set up, look around in this forum, there are several threads with the experience of the users. Especially the experiences with different providers are very interesting.

HTML code
When you create your page, you should pay attention to two things. First, use valid code. The more bugs your code consists of, the longer a browser needs to render it. Second, use less objects. A lot of people are using to many images, flash and javascript on their site. There have been great improvements in the connection speed of a lot of users and broadband connections exceeding 1 MBit are not as uncommon as just a few years ago, but the vast majority of all users are still dial-ups with a modem or ISDN connection. If you don't want to exclude 90% of the web community, you should keep your site small. There are several services out there that can analyze your site, I will only mention the Web Page Analyzer from Websiteoptimization. For the validation of your HTML code and Javascript, I can only recommend the Web Developer Extension for Firefox. You can get it here.
These things can improve your sites speed drastically and you should really look into this!

Images
As I wrote in the previous paragraph, small is beautifull. This also applies to images. Take a look at your images and see if you really need them in a resolution of this size. Wouldn't a picture with half the dpi look as good? Often people don't notice that they are using images the size of lower Manhattan because they set the size in the HTML code to something way smaller and their browser has the images in his cache, but others first have to load a huge image and then it gets reduced to the size of a stamp. This takes a lot of time for them and they don't want to wait that long. So see to a reasonable size of your images both in pixel and in bytes.
Another thing that's often slowing down the performance are missing images. If you have a reference to a non-existent file, the server will need a lot of time to notice that and answer with a 404. In some cases your server is configured that way that you are redirected to the frontpage when the server can't find the file and in that case the browser receives a complete new page each time he requests a missing file. Imagine just one page with an image that is used at a dozen places in the layout and is not present. This can slow down the delivery to up to half a minute!

PHP accelerators
If you can't afford a new server and you are on your performance limit, think about buying a PHP accelerator. There are again numerous available, like Zend or APC. Just look in this forum for further information. They can do little wonders about your performance.

Joomla specific Optimizations
Used extensions
You have installed Joomla and you have found all those neat little extensions available on extensions.joomla.org. You have installed numerous of them and think your site looks really cool, but lately you have to wait several seconds till your site pops up.
Again, this is another example of small is beautifull. Joomla needs a lot of extra time for each module or plugin it has to load. I guess you can think where this is heading: Use less extensions and try to make the best out of the few you really need.
In this regard, you should take a look at your extensions and see if any of those uses an external datasource. If your server first has to load the data from another server, process it and then send it to you, this can take up several seconds. Try to find an extension that does the same but stores the data on your server. If the other server has a failure or is getting DoSed, your server will not be affected by this, too, since it is just reading from its local data source.

Database
Great potential lies within the database. In general we recommend you to allways use the latest version of Joomla, since for example there were big improvements from 1.0.7 to 1.0.8 and there are even bigger improvements coming in 1.5. (1.0.8 uses about half as much queries as 1.0.7 and 1.5 does the same trick with about a quarter of the amount of queries from 1.0.7)
If this is not enough for you, you can also enable query caching in MySQL. This will cache a lot of queries in the RAM of your server and make it fast as a bullet, but be carefull, you really need A LOT of RAM. 2 GByte is not uncommon and more like the lower starting point for this. This is nothing for shared hosting!

Debugging your site
I also recommend switching on error reporting in PHP and setting it to its highest setting. You will probably have to correct some errors in the code to get them all away, but they, too, are wasting precious CPU time and therefore performance.
If you switch on debugging in the Joomla backend, you get a list of all queries executed for this site in the frontend. If you see a number thats to high, you should hunt those down and see what can be done about reducing that number.

SEF/SEO
Last but not least we have SEF/SEO. This takes a lot of CPU power and if you have problems with your server, you should switch that off as the first emergency measure. Due to some errors in erlier Joomla versions, SEF sometimes produced dozens or even hundreds of useless queries.

With these things you should have your server going a lot faster than previously. If you still have problems, please post into this board and we will try to give you specific help on this one.

　日前，媒体报道Win10政府版未通过政府审核，然而很多地方却开始推广Win10政府版。出现这种现象其实和CPU方面，自主CPU得不到重点扶持，技术引进CPU却能拿到巨额经费类似，都是当下对自主可控缺乏统一标准和认识的体现。由于国家缺乏宏观规划，结果自然是"八仙过海"，地方政府在短期利益和利益集团的驱动下，Win10政府把未过审核就试用也就见怪不怪了。

WIN10中国政府专用版是什么鬼

　　Windows 10中国政府版由微软在中国大陆成立的合资公司神州网信开发，合资公司主要任务是为中国政府和企业定制Windows 10系统，根据微软和中电科的合作声明，主要包含三点内容：

　　新成立的公司（神州网信）将作为中国境内微软产品的唯一代理；

　　双方将展开合作，为中国政府机构和负责国家基础设施的国有企业提供操作系统技术与服务；

　　中国电科相关子公司将加盟"微软合作伙伴网络"，签署"微软开发者高级支持服务协议"，微软将对其提供Windows部署、支持和最佳实践方面的技术培训与认证。

　　虽然中国电科占股51%，但实际上中方根本没有掌握Windows 10的技术知识产权——微软和中电科的主要合作内容并没有涉及核心技术和知识产权，也不涉及Windows系统内核开发能力培训、以及技术共享和转让。而微软Windows和设备集团副总裁Yusuf Mehdi也表示，"微软将保留所有关于Windows 10的技术知识产权"。

　　铁流猜测，所谓WIN10中国政府专用版是删除或者屏蔽了一些中国政府容易被关注或者比较明显的的模块，比如某些云功能，部分安全模块，但屏蔽多少，删除多少，仍然不透明。

　　如果猜测属实，那么，WIN10中国政府专用版，本质上就是WIN10的马甲，所谓"中国政府专用版"则犹如皇帝的新衣，是国内买办意图将WIN10引入党政军市场的遮羞布。

Win10政府版未通过安全审核却被地方政府采购

　　在斯诺登事件之后，政府进一步加强对国内网络安全的审查，自主可控等政策相继出台。Windows8就因为存在安全隐患被党政机关禁止采购。由于Windows10和Windows8属于同一个架构，因而同样存在安全风险。倪光南院士指出，Win10系统存在被监控、被劫持、被攻击、被禁售、密钥和证书失控、无法加固、无法打补丁、不支持国产CPU等安全风险。

　　权威测评机构对Win10也做过分析、测评，证明Win10和Win8属于同一架构，名称的不同只是为了销售的需要，因此政府采购早些时候对Win8的禁令适用于Win10。特别是Win10捆绑微软可信技术，其内涵违反中国的《电子签名法》和《商用密码管理条例》。

　　另外，倪光南院士还在多个场合批判过所谓的Windows10政府版。沈昌祥院士也表示：审查小组提出3个原则，电子证书系统国产化、应使用中国的商用密码系统、应使用中国的可信计算技术（原可信计算技术下，第三方软件要经过微软的认证才能运行），由于违背这3个原则，Win10政府系统并未审查通过。推广Win10将直接威胁网络空间国家主权。

　　即便如此，微软依旧通过运作，通过神州网信这个代理人，把Win10政府版操作系统打入党政市场。目前，山东、上海的一些单位已经开始试用Win10政府版，联想则有望成为首个预装Win10政府版的厂商。

将对自主CPU和国产操作系统造成冲击

　　近年来，自主CPU发展迅速，不仅在通过深耕嵌入式芯片在商业市场上养活了自己，在技术上也不断取得突破，在党政市场的应用中，也逐步完成从"不好用"到"可用"的转变。

　　目前，自主基础软硬件在CPU方面有了龙芯和申威；在操作系统方面有了中标麒麟和深度；在数据库方面有了达梦、金仓；在办公软件方面有了WPS和永中......已经初步具备了自主研发软硬件的能力，虽然没有Wintel好用，但也可以满足基本的办公需求。

　　如果在买办的帮助下，使Win10政府版堂而皇之的进入党政市场，一方面会给国家信息安全带来隐患。另一方面也会使自主基础软硬件收到冲击。

　　毕竟国产操作系统相较于Windows如同是让成年人与幼儿同场竞技，必然导致国产操作系统的全面溃败，等于是前功尽弃。

　　由于软件和硬件的高度一体化，这将对自主CPU造成巨大冲击，毕竟自主CPU跑不了Win10政府版，当年Wintel软硬件捆绑可是把一众RISC处理器搞死搞残，刚刚初具雏形的自主基础软硬件被扼杀于萌芽状态。

亡羊补牢为时未晚

　　历史已经多次证明，虽然产品可以买到，但技术是买不到的，自主技术能力更是买不来的。自Win8开始，Windows就被政府采购所禁止，但如今却在带入党的带领下，有可能重新进入政府采购，着实让我辈草民匪夷所思。

（会议横幅值得深思）

　　美国制裁中兴尚历历在目，而中国却对美国公司大放水：

　　银行业的IOE运动不了了之，而且相关部门在没有进行网络安全审查程序的前提下，却把涉及网络安全、信息安全和金融安全的苹果支付放进中国市场；

　　IBM、ARM、Intel、高通、微软等选择与国内合作/合资，穿马甲后全部成为"自主知识产权"；

　　《反恐法》最终版本中有关数据本地化的条款也顺利消失了；

　　多年来没法进入政府采购的思科产品居然借助与浪潮的合资，开始重新回归政府采购目录

　　......

　　前事不忘后事之师，希望决策者能够吸取教训，亡羊补牢。