Most broadband packages these days offer “Up to 8MB“…however most people get an average of about 4MB at least, from that. It all depends on how far away you live from the telephone exchange.
However if there is something wrong, your speeds can be greatly reduced.

Some Problems you may be experiencing:

• Constant slowdowns during peak times
• Regular disconnections (More than say three times a day)
• Slow downloads

Step 1: Check Your Internet Speed

You can test the internet speed you’re getting by going to speedtest.net.

Make sure you have nothing running in the background that may be using the internet. Then put your mouse over the yellow star, and click the nearest city to you.

If you find you’re getting an extremely terrible result, something like less than 1.00 MB/s or even 2.00MB/s, I advise you put in a complaint with your ISP (Internet Service Provider), there is likely something wrong with your telephone line, or something going on at their end.

Step 2: Complain to your ISP (Internet Service Provider)

Give them a call and explain you’ve done a speed test, let them know what the result was, and explain that you’re very unhappy with your broadband performance. They should then run a “line test” and see if theres anything wrong.

If your problem is constant disconnections, obviously explain this problem too.

Here are some ISP Broadband helplines and their respective Broadband Web pages:
BT Broadband: 0800 111 4567 – Weblink
Orange Broadband: 0844 873 8586 – Weblink
AOL Broadband: 0844 499 5555 – Weblink
Virgin Broadband: 0845 454 1111 – Weblink
Sky Broadband – 08442 410 515 – Weblink

Step 3: If Your ISP don’t seem to be Helping

If your ISP insists on being useless and fails to improve your speed or reliability, explain to them that you’re extremely unhappy with their service and you’d like a MAC code. You are within your rights to ask for this whether you’re in a contract or not, since they’re not delivering a satisfactory service.
A MAC code is needed to change broadband providers.

Step 4: Change ISPs (My Recommendation is Be Broadband)

I used to use BT Broadband and we were with them for over four years, to our detriment. They provided a god awful service, constant slowdowns during peak times (below 0.5mb/s) and frequent disconnections. We’d had enough, rang up BT and asked to cancel our broadband, and wanted a MAC Code. They begged us to stay and offered a discount per month. We refused and since then we’ve used various other ISPs.

We’re now using Be Broadband, who are by far the best ISP we’ve experienced. The price is reasonable for “up to 24MB” and there’s pretty much no download limit. I have downloaded ALOT and have yet to recieve a warning. Click the animated Link above to check out their website.

Step 4a: Alternatively Try O2 Broadband

Be is owned by O2 broadband, and therefore provide a very similar service. I advise you give them a try.
Link: http://broadband.o2.co.uk/home/index.jsp