I want to know whether T9300 penryn processor is 32 bit or 64 bit? I read somewhere that it supports 64 bit but surly it is not IA-64.
 
So what is it?

It is a 64 bit processor.  Now if your question is does it also run in 32 bit mode than the answer is yes.  If you throw a 64 bit OS in their it will be 64 bit and with a 32 bit it will be running in 32 bit mode.

That page says that it has EM64T support. Is it different from IA-64?

 
No it will run all your 32 bit and 64 bit apps.  In other words it is backward compatible.

EM64T is different from IA-64. They are both 64-bit architectures though and most people will never see a IA-64 processor. EM64T is Intels variant of AMD64. There are some slight differences though regarding the memory management. Intel has to emulate the addressrange above 4GB while AMD does that in hardware.  
 
The bottom line is EM64T processors can run 64 and 32 bit applications.

Now that we are on this topic, a little clarification would be appreciated. Forgive me if the  question has be obviously answered.
I am in the process of building a new computer and cannot decide on the operating system. Will 64 bit be backwards compaible with 32 programs. If so, is there any disadvantage to using a 64 bit operating system with 32 bit programs.
 
Thanks in advance

Thanks. good information I received

 
Yes, if the operating system chooses to support them.
 

 
Yes. The 32-bit programs will run slower because of the 32->64-bit translation layer for operating system calls; for example, if your operating system wants a 64-bit memory address and your 32-bit program passes a 32-bit memory address, the translation layer has to convert between them.
 
However, unless you're doing something performance-intensive like games, you won't notice. I run 32-bit Firefox on 64-bit Linux due to lack of a 64-bit Flash plugin, and there's no difference in performance over running 64-bit Firefox.

Thanks for you informative reply.
Since I do not play games, would I be better off with a 32 bit operating system?

No go with 64 bit

 
 
IMO You will be better off 32 bit OS for compatibility reasons.  I.E. it's harder to find 64 bit drivers.  My advice would be to stick with 32 unless you absolutly need over 4 gigs of memory for some reason.

Actually, I meant that unless you're playing games or something else CPU-intensive you won't notice the performance hit of running 32-bit applications on a 64-bit OS . So in that case there's no reason not to run a 64-bit OS.

Of course if you're not doing anything CPU or memory-intensive you won't see any immediate benefit from 64-bit either aside from a few security improvements (the large address space can be used to eliminate DLL address relocation and to randomise the addresses which are used, and I think the 'no execute' bit only works in 64-bit or in 32-bit with PAE enabled?).

How about chipset, memory, bus and other components? Should they be 64-bit compatible?

Ok, even I am getting confused by all the replys.
 
Its simple.
 
If you are using 3GB of ram or less stick with 32bit O/S
If you are using 4GB of ram or more you need a 64bit O/S
 
Between 3 and 4GB its your call, 32bit O/S will not see all of 4GB but you wont loose much.
 
As for speed. I have some programs that run alot faster under Vista64 than Vista32 and they are 32bit (and one is a game that goes 80% faster on the graphics due to the graphics driver using 64bit calls), I also have some programs that run very slightly slow (at most 1% slower so its not noticeable really).
 
Drivers were a problem with early 64bit O/S's but Vista64 is becoming main stream and the drivers are now usually available in the same way 32bit drivers are. I don't think I have come across a driver problem for a long time where I could not get hold of Vista64 drivers but a Vista32 one was available.
 
All current and modern systems are fully 64bit compatible. there may be some really old Intel chips that dont support 64bit O/S's but all Intel, AMD, ATi and nVidia chipsets, processors and graphics cards for the last 2 years have had full support for 64bit O/S.

I only ever upgrade an OS when the first service pack comes out, never before like many pro's in the IT industry. I have upgraded to Vista64 and use 64 bit CAD and 3D programs on it and basically I damm love it!! People were moaning about Vista but the only thing I had to resolve was my motorola SB5100 cable modem, which basically needed a $3 Ethernet cable as apposed to USB, that's it!! 64 is backward compatible with 32 bit software with caveats, so check to see all your important software will be ok.