what are the advantages of 64 bit programs
do they run faster or something
someone plz explain

Well, 64 bit programs can process the information at 2x the speed that we can now because it gets twice the flow from the processor.

think of them as channels... if you open up twice the amount of channels, twice the data can flow through at once.

But you need a 64 bit machine to run them on.

A CPU processes data and instructions. In a 64-bit world the larger data chunks and larger more complex instructions both result in more being done in less time.

The reason people say what good is a 64-bit cpu in a 32-bit world is because today's programs and their data chunks can all fit fine within the 32-bit registers of a 32-bit cpu.

Today's world is like a one-armed man juggling one ball. Tomorrow's world will be like a two-armed man juggling two balls. Until that second ball enters the equation (programs written in 64-bits instead of 32), his extra arm (a 64-bit cpu) is of little value.

64-bit programs aren't twice as fast. It's not that simple. With 64 bits, one can address more than 4Gb of RAM. At one time there was a 32-bit filesize limit also, but they've worked around that (see NTFS vs. FAT32). Memory is more difficult.

Cyrptography and some compression algorithms will benefit from 64 bits because they use 64-bit numbers. Most programs don't use 64-bit math as heavily, so there is little increase in performance.

An interesting area where we could see a performance increase is programs that could use 64 bit integers rather than larger data types (related to the above advantage). A 64-bit integer would be much faster because it would only take up one register. I read that games might be able to do this. It would require rewriting game engines, but it could give that 2x performance increase subrogate mentioned.

The real reason AMD's 64-bit CPUs are about 20% faster in 64-bit mode is more registers. x86 CPUs have too few registers and AMD's 64-bit extensions add many. AMD figured if they're going to make a new standard, why not add more than just basic 64-bit funtionality.

The difference is not speed but bandwidth.

You can think of it as a freeway. You can fit twice the amount of cars on a 8lane freeway then a 4lane freeway but thay all still go 55miles an hour.

32bit is 4lane and 64bit is 8lane.

As Jake points out the biggest advantage is memory addressing.

The folks who are rushing out to get 64bit systems for home use... can you say premature. Silly to think you are getting more with 2.4ghz 64bit processor than a 2.4ghz 32bit processor. Fact is until they have 64bit programs its a waste. And 2.4ghz is 2.4ghz

"Fact is until they have 64bit programs its a waste."

AMD's 64-bit extensions may be a waste without 64-bit programs (for Windows anyway), but not the entire CPU. Athlon 64s and Opterons are significantly faster at 32 bit code on 32 bit OSs than Athlon XP/MPs.

well microsfot just released a free trial version of Win64
has anyone tried it?