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10/5/2009
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If you are accessing a distant web-page from home the performance (speed of response) you get depends on a lot of things. Many of them you can do nothing about, but some you can. So, why don't you?
The things you can do are listed later, but the background comes first because if you don't understand a few basics you still won't get it right.
Introduction, bits and bytes, the client/server model, the server, the network, the client, cookies, applets, cache, operating system, PC hardware, you, a summary of things to do, references.
First you need to understand that there are a lot of links in the chain. Let's simplify them into three areas: the client, the network and the server. Clients and servers mean some specific things to purist techies but we'll take a more general view to start with. By client we mean everything at your end. By server we mean everything at the other end. And by network we mean everything in-between.
Before we move on don't forget the difference between bits and bytes.
A bit is the basic item of computerised information and the transmission rate of information transferred between computers is usually expressed in bits per second or bit/s (in the USA abbreviated to bps). Units of thousands, millions and a thousand million are commonly used: these are kbit/s, Mbit/s and Gbit/s respectively (or kbps, Mbps or Gbps in the USA). Your modem will be rated by its maximum bit-rate, e.g. 56 kbit/s.
A byte is a collection of bits frequently referred to in the context of storage or file size. Bytes also often come in multiples of thousands, millions and a thousand million called kBytes, MBytes or GBytes. Your hard-disk drive will be rated by its maximum storage capacity e.g. 10 Gigabytes.
There are 8 bits in a byte. So if you downloaded a 100 kB file at 50 kbit/s there would be 800,000 bits (100,000 x 8) to ship across at 50,000 per second and it would take 16 seconds.
The simple model can be broken down further. Here are some of the component parts of each:
CLIENT:
- you
- your PC hardware
- your PC operating system
- your browser
- your modem
NETWORK:
- your access network hardware (such as copper telephone wires, cable-tv, how long the link is, and so on)
- the way your network provider connects between you and your Internet service provider
- the way your Internet service provider connects to the wider Internet
- how congested common links are
- where the distant computer is
- the way the computer the web-page is on connects into the web (a bit like the first three items in this section the other way round).
SERVER:
- the hardware making up the computer that the web-page is on
- the software used by the computer the web-page is on
- the way the hardware and software are set-up by the system administrator
- the software used to create the web-page
- the way the web-page creator used the web-page creation software
- the content on the page - especially the use of adverts, cookies, graphics, and "advanced" features like Flash and Java.
The things you have the most control over are the client issues and your choice of network provider and Internet service provider. But what you do on the client side still depends on the rest, so we'll look at the issues in reverse order.
The server end.
There is very little that you can do about what happens at the server end but it helps if you understand a couple of things.
One is that you can't tell where the server is just from the URL (the uniform resource locator, or the web-page name, that you type in the browser address box). The network converts the name to an IP address using a domain name server (DNS) look-up and the IP address can be anywhere. (Techies can find it out using ping and/or traceroute but that's another story). A .co.uk URL may be hosted on, or forwarded from, a computer in the USA or anywhere else. It may be more likely to be in the UK but that's about it, nothing is certain. Wherever it is, the peak time for congestion will depend on time zones. The best time in Europe to do heavy surfing, or software downloads, from USA sites is in the morning before east coast America wakes up by lunchtime in Europe. It gets worse by late afternoon when west coast America wakes up.
The other is to know is that the provider of the web site may have completely different aims to you. You may want to see what's there, get to it fast and move on. They might want to keep you there as long as possible - especially if they get funding from advertisements, of which they want you to see as many as possible. They may want to track what you do using cookies and think you want to be entertained when you don't.
Some sites are meant to look good to Corporate chiefs who don't understand the merits of fast response times. These are often heavily graphics intensive and are most annoying with Flash 'movies' that you can't bypass before they finish or with java applets that you can't stop loading. Life gets more difficult on this front with some broadband users actually wanting the heavy stuff, most users not wanting it and mobile WAP (wireless application protocol) users wanting even lighter-weight pages. TV users will add even more confusion to this scene soon with different display needs, but the best sites give you choices depending on your client capability or even pre-detect it.
The best sites are put together by people who understand all this. Unfortunately there are a lot that don't. The references give a book that gives tons of good advice for people running big web-sites.
You may be lucky enough to have a broadband link - such as ADSL, a cable modem or even a 10 Mbit/s Ethernet connection if you live in a few favoured apartments in Scandinavia or the USA. But most users still have dial-up (analogue phone-line) connections into the Internet so we'll concentrate on that here. Most of the advice holds for ISDN (digital phone-line) which is sort of in-between.
Remember that you are only using the network when you send data (as in requesting a web-page, or sending an e-mail) or receiving data (when a web-page or e-mail is being downloaded). If you are just reading a web-page or an e-mail there is no network activity. Of course if you use the Internet for listening to a radio station then data is continually being downloaded (streamed). Voice telephony use is in-between.
If you use Microsoft Windows you can usually find the bit rate that you get in practice on your dial-up connection by putting your cursor over the tiny "two linked computers" icon visible at the bottom right of the screen. (If you blink and miss the information just reposition the cursor and return it again). If you have a 56 kbit/s modem don't assume that you will get 56 kbit/s - in fact it is highly unlikely. The bit rate can vary from connection to connection but will generally be determined by your line and exchange (central office) characteristics and you'll get to know what is normal for you. Rarely will it be better than 33 kbit/s and often it can be less than 15 kbit/s but 56 kbit/s is the highest standard you can get over a standard copper analogue dial-up line.
The end-to-end performance you are getting from the network at a particular time can sometimes be determined - e.g. use a watch to time downloading software of known size (but don't forget the bytes to bits conversion). Even users of high-speed company data-links accessing the public Internet discover that they sometimes only average about 6 kbit/s due to all the other performance constraints.
You can also use the information from the "two linked computers icon" again. This also counts the bits in and the bits out. If you want to see how little you use of the capability during an on-line session, multiply the time you are on in seconds by the link bit-rate to get the theoretical maximum throughput. Then see how much you have really used - probably just a few percent for general surfing. Now did you really need a broadband connection?
Electrons travel at the speed of light (300,000 kilometres/sec or 186,000 miles/sec) but this is only in free-space. Your Internet bits travel over cables with equipment at the ends. This slows it all down due to optical to electrical translations at the ends of optical fibre cables but on top of this there is the way the bits get from one end to the other. All the data on a web-page is sent in packets and these are routed in the network by devices called routers. These are themselves computer driven and check every packet for its destination and send it on in the right direction. Not all packets go the same way so they have to be collected and re-assembled in the right order before they appear on your screen. All this checking and re-assembly takes time which causes delay - fortunately the delay is not noticeable a lot of the time. When it is noticeable it can be due to a data intensive page and/or to congestion on the network - that is, a lot of people trying to send or receive data at the same time clogging up the router computing capacity. Congestion is more likely the more data that has to be sent and the more the number of links the packets pass through to arrive.
The client
Lets go through the opening list for the client in the reverse order too.
Your modem
We've already looked at modem speeds under the network heading. If your dial-up line is fairly good and you do not have a 56 kbit/s modem you may be losing out. Check your modem spec and check the speed you usually get when connected. If you run at the maximum speed of your modem and it is less than 56 kbit/s then consider upgrading your modem.
Your browser
When you first connect to the Internet with your browser you get an opening page. A default is usually chosen by the browser producer (mainly Microsoft or Netscape) or by your Internet service provider if they gave you a free copy of the browser software. If you like it fine - but it is probably a complex page which takes a while to load giving you delay right at the start. Research shows many people never change it and many don't know how to.
Some popular advice says the quickest is to use a blank page. This is true, but I prefer to use a simple page with no adverts or cookies from a well-built high capacity site. That way you do at least know that your connection and the wider Internet is working (but see caching below). If you have an old slow computer and a poor access line then maybe the blank page is for you. You change the opening page in Netscape via Edit, Preferences, Navigator, in MS Internet Explorer (IE) 3 via View, Options, Navigation, Customise and in MS IE5 via Tools, Internet Options, General.
Another way to speed-up hunting for information, as opposed to looking at pictures and pretty graphics, is to switch the browser to text only. In Netscape go to Edit, Preferences, Advanced and uncheck the auto load images box. In MS IE3 go to View, Options, General, Multimedia and uncheck the show pictures box. (IE5 via Tools, Internet Options). This will cut out lots of adverts as well. If you do want an image then just double click the image marker to load it.
Cookies
You will get better performance with cookies enabled. But I object to sites collecting info from me without me knowing. I prefer to have the cookie filter on and take the performance hit. Switch it on in Netscape 4.7 via Edit, Preferences, Advanced, Cookies, and in MS IE3 via View, Options, Advanced, Warnings. Most shopping sites will need you to enable cookies (legitimately to add to your cart) so for those just say yes instead of no to the filter request. A few sites will not work without accepting cookies - for those you can decide whether or not to go ahead. I just usually move on to another site. You can control cookies through some firewall programs like Norton Personal Firewall instead if you have it installed (and if you haven't you should).
Java applets
A java applet is a small program that is downloaded from the source of the web-page and runs on your computer. Generally if it starts loading you have to wait for it to finish before you can do anything else. It is better to download these by your choice rather than someone else's. You can set these through similar settings to those shown above (e.g. in IE5 via Tools, Internet Options, Security) or through a firewall program.
Cache
A cache is a temporary store and your browser will almost certainly be set up to store all the text and images associated with the web-pages you have looked at in previous sessions up to a certain limit. This (adjustable) limit can be quite large running to thousands of file entries. There are two sides of this from a performance point-of-view. The browser can be set-up to pull out the files from the cache if you have accessed the URL (page) before and then to verify from the original web-site that the data is the same. There are several actions here: checking the URL in the cache first, then retrieving the page from the original site, then doing a comparison, then updating it if appropriate. There are two possible ways of cutting out these actions. One is to set the browser not to check with the original site and live with possible out of date material. The other is to delete the files from the cache from time to time. The latter means that there is less to check first but the latest material is always downloaded. Go to Netscape go via Edit, Preferences, Advanced, Cookies, in MS IE3 to View, Options, Advanced, Temp Internet Files, Settings, Empty, and in IE5 via Tools, Internet Options, advanced.
Your operating system
This applies to Microsoft users - if you are not using MS-based products you probably don't need advice from this page. Tuning the operating system needs some good technical advice but there are a couple of things you can do to keep your computer at its best. One is running scandisk now and then. The other is to defragment the hard disc now and then. Find them under the Start menu (bottom right button), then Programs, then Accessories, then System Tools. Allow a lot of time for a disk defrag if it needs doing (typically when stored program data is more than 10% fragmented). For a several Gbyte disk allow an hour or so and leave it to it. This should improve your computer performance generally, not just when using your browser.
You might want to clear out temporary files from Windows from time to time as well.
Your PC hardware
It is easy to get hyped up on PC specs. If you want the latest and best, especially for gaming, that's fine but the rest of us get by with a PC of some years standing. If you have a PC with a processor speed measured at more than 100 MHz and some RAM (temporary storage) of 32 Mbytes or more you should find the rest of the Internet is slower than your computer. If not it might be time to think about a change. The PC is a complex beast and there are limitations not covered by the specs that appear in the newspaper and magazine adverts but a new higher spec one will be a noticeable improvement over one that is 5 or 6 years old. Unsung parts like the graphics card can have a measurable effect on perceived Internet performance.
You
Lots of people do not realise that you can open multiple windows in most browsers. This means that you can start loading one page in one window and then move on to another to read what is already there. It is common for computers to do multiple tasks at once. People are capable of multi-tasking too - some psychologists say that women are better at it than men and a few have produced humorous books on the subject. Working the two together means that the computer can be busy loading the next few pages whilst you look at what is there already.
You open a new window in MS Explorer and Netscape by going to the top of the screen and opening File, New Window. Then using minimise (the "-" button in the top right of the screen for the window you are working in). They appear on the bottom row until you call them back again by clicking on them.
Summary of things to do
- Check what access speed your modem normally runs at over a few sessions.
- Consider changing your comm's provider if you are not happy.
- Upgrade to a 56 kbit/s modem if you have a slower one that consistently runs at maximum speed on your connection.
- In Europe do software downloads from the USA in the morning (get up earlier at weekends!).
- Use a blank or simple (short, advert free and cookie free) start page on your browser.
- Switch-off loading graphics for fast information hunting.
- Either don't check for new page data from cache or clear the cache from time to time.
- Do housekeeping on your PC from time to time like clearing temporary files, running scandisk and doing 'defrag'.
- Open multiple windows.
References:
Web Performance Tuning, Patrick Killelea, O'Reilly & Associates Inc, ISBN 1-56592-379-0 (mostly concentrates on the server end)
Good description of the principles of the Internet: click on Vol !8 No 3, then the article by S Challinor: An introduction to IP networks, here.
Information is provided in good faith but the responsibility for making use of it is all yours and there is no warranty that it will work and no liability for any consequential problems.
Copyright, Ian Dufour 2001
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Written 17/4/2001, Updated 26/4/2003