Originally posted by: Gooberlx2
Originally posted by: AndyKH
Originally posted by: LuckyTaxi
still dont understand the point of running 64bit. most apps arent even 64bit ... yet. waste of money.
There is more to Vista 64 bit than just being able to run 64 bit programs: The most important feature besides being 64 bit is the ability to handle lots of memory. If you install 4 GB RAM in Vista x86 or XP x86, you will not be able to use more than ~3.3 GB - the rest is lost. Also, with a 64 bit OS it's easier to get around the problem with the 2 GB virtual memory limit in 32 bit OSes. Granted you can change the limit, but that might result in instability.
In addition, IIRC from my old CS days (didn't pay the greatest of attention), 64-bit is inherently better at number crunching, which should translate in to better performance for things like audio/video encoding. Is that right?
Yes, that's right. For many applications you're just doing things like clearing
large memory regions to a specific value, or searching for data within a memory region,
etc. If you use 64 bit registers and memory operations it'll tend to go faster than issuing
twice as many 32 bit operations for the same kinds of tasks that need to operate on
large multiples of 32/64 bits worth of data.
Of course if you use 32 bit registers and your program occasionally needs 64 bit
integer precision e.g. an "long int" variable, it'll have to emulate the 64 bit arithmetic
checking for carry, etc. with several additional instruction steps and use
doubled-register source and destination encodings whereas with 64 bit native registers
it just does the operation in one simple instruction.
Of course there are things like SSE instructions to operate on wider or vector
data sets even under 32 bit execution mode for applications that benefit from
those. So in special cases like that or using FPU registers that are inherently
80 bit / 64 bit in double precision more there's less difference between operating
the main instruction set in x32 vs x64.
I just installed vista x64 on my PC with 8GB of memory and it's working more or less
nicely for both 32 bit mode and 64 bit mode programs so far... LINUX x64 still seems
a lot more powerful, though.