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Speed is Important Connection Speed Download Time Display Time Measuring Download Time Reduce Download Time Get Faster Display |
Speed is ImportantEnd of November 2009 Google announced the download speed is getting more important. Google's ranking algorithms are going to include the download speed as one factor for ranking websites. You can check Download speed for your own website, pictures are not included in this test. Beginning of April 2010 Google made a new announcement: speed is now included as one ranking factor. In fact, it's not correct to talk about increasing download speed. The download speed is outside your control so you cannot increase it. What you can do, is to reduce download time. This you do by keeping as simple and short code as possible plus reducing file size for every necessary image. Naturally you wouldn't include any unnecessary pictures on your pages. Because people are getting more and more "frenzied" when surfing on the net the surfers want everything immediately. We can therefore soon expect to see slow downloading webpages to slide down wards in the search engine results pages ( SERPs ) being replaced with faster downloading web pages. Recent research shows 8-10 seconds is a strong limit for the download time even with broadband. Connection SpeedThe speed is counted in bytes/sec. or KB/sec. (1 KB = 1024 bytes) and is specific for each computer and connection. Depending on the traffic volume at different Internet Service Providers ( ISP ) the speed is variable. It is higher or lower at certain times of the day/week. You can check the connection speed for any computer / connection at browserhawk.com/. With a broadband / DSL cable connection you can expect about 20 - 30 KB/sec. or even considerably more, while a modem + telephone line connection often is as low as about 2 KB/sec.The connection speed you get is a theoretical one and is measured by sending a certain quantity of data over the connection you are using. Which way and via which intermediate servers / ISP's your connection goes each time your browser connects to an internet website is out of your control. The greater number of intermediaries the lower is the connection speed. You can use the connection time value to rank different computers / connections in your hometown. To get the real total display time for a certain page you must, however, use a stopwatch. The real total display time can be divided thus:
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| Check Menu | Download TimeThere can easily be much more than 100 customers at the same server at any one time, each one downloading from a different site. To optimize the server's service, each page code is split up into packages delivered as a train with several wagons. One can imagine the process as follows.If the file requested is large, the file itself can easily be split into several packages, as, for instance, "interlaced .gif" pictures, which are delivered by and by in several slices, very often 3 slices. Each page code is sent in packages so that each customer gets a small package at his turn. Between each package coming to your computer there can then be a hundred or more customers receiving their small packages. That's why the download time gets long when the server is busy (= very many customers in line). The server is optimizing the total service time for all customers at each point in time.
The browser has to request each file, like external files (.css or .js), separately, same as with picture files. If the external file is your style sheet may be it comes in two packages and your text cannot be displayed before these files have been processed. As the text is displayed first directly from the downloaded "main" code and the external files may be come later, it will have an effect of parts of the page like floating around and looking for their final resting place. While this goes on your visitor has to wait because he/she cannot start reading before the process is done. The modern browsers do save the style sheet files in the cache, although Explorer 6 sometimes refuses to up-date a saved style sheet. So how to know what code to use and when? When choosing between CSS and HTML, ask yourself if you can get same or almost same display with simple HTML. If you can, then use HTML because the code is shorter and therefore the download time is also shorter. It also explains why it is important to indicate to the browser the physical size of the pictures ( in pixels ). When that is specified your browser simply reserves a place for each picture and displays the text around it while still downloading the picture code. When you arrange some text in the beginning of the your page as well as between the pictures, your visitor have something to occupy himself / herself with (= reading the text ) while the picture(s) are downloading. Display TimeOnce your browser has received a package, it starts processing the data and at the same time downloads the next package etc. To a human it seems like the browser is doing 2-3 different things at the same time, which is in fact exactly what the browser is doing.
The process of receiving your files could look like in Diagram 2 above. "Text #" and "Pic #" are the separate requests received from among the middle of other customers. Text #1 can be imagined as being your request from Diagram 1 above. Diagram 2 explains why external files (.css or .js) increases download time. The browser has to request each file separately, same as with picture files. If the external files are your style sheets may be they come in two packages and your text cannot be displayed before these files have been processed. Mixing JavaScript, external CSS, and HTML makes page elements like seeking their place on the page before the display is processed and the page settles down. On average people wait only 8-10 seconds before leaving your page. In this time your background, your logo, and at least some of the first text should be displayed. Measuring Download TimeTo measure the real download time you need a stop watch.First you type in the URL for the page you want. At the same time as you hit "enter" you start the stopwatch Then you look in the lower left corner of your screen. First you will see: "Downloading ...". By and by when more of the page is displayed you can scroll down. Once the screen (down in the corner) says "Done" it still takes a short while before the last is displayed At same time as the last is displayed you stop your stopwatch and now you have the total display time of that page on your computer with the actual connection you are using. You can do the same test on some public computers with different connections in your hometown. When you check your own site/page this way, be prepared for some negative surprise. When you check your own pages, try to use as many different browsers, browser versions, and connections you can find. Older browser versions usually finish the display after a longer time, compared with the latest versions. |
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| "Advanced" Tables Code | Optimize your Webpage | | Cascading Style Sheets - Pro and Con | | Reduce Picture File Size | |
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