How important is 64 bit?
I've got a MacBook at the moment. 2.0ghz CoreDuo. I want to buy the new iMac when Leopard comes out so i'll have the Core2Duo with Leopard's 64 bit setup. Am I reading too much into this? How much faster will it actually be?
If the difference is minor then i'll probably use the cash for the touch! No iPhone in the UK yet
If the difference is minor then i'll probably use the cash for the touch! No iPhone in the UK yet
Comments
64 bit means it can utilise over 3gb of RAM. leopard will work fine on 32 bit machines, so unless you need to use over 3gb of RAM the difference is trivial.
A 32-bit machine can easily access well in excess of 3 GB of RAM. However, a 64-bit machine can handle extremely large databases and such.
64 bits only comes into play if you have *one chunk* that is in excess of 4GiB, such as, yes, a database file, a movie you're editing in HD, or other large data sets. (I've had my own work produce analyses in excess of 1GB of process space for a few data structures. That *hurt* on a 512MB machine. Oh god, the swap thrashing was horrible.)
Bottom line: 64 bits doesn't really get you anything in speed, and only gets you data access capabilities that most people will never use. But, like, it's bigger and stuff.
A 32-bit machine can easily access well in excess of 3 GB of RAM. However, a 64-bit machine can handle extremely large databases and such.
um no it can't. name a 32bit macintosh which can address more than 3gb of RAM.
kthx
On Windows machines the problem is complicated by people who can't or won't use a 64 bit version of XP or Vista because of crappy or nonexistent drivers. All of those 64 bit machines will probably never see 64 bit code ever.
Back on the memory improvements, it'll be a while before 2GB laptop RAM prices come down to be really reasonable. Do 4GB SODIMMs exist yet?
um no it can't. name a 32bit macintosh which can address more than 3gb of RAM.
kthx
Bogus question. My 32-bit MBP can't address more than 2GB. But that's nothing to do with the number of bits in the addresses.
Bogus question. My 32-bit MBP can't address more than 2GB. But that's nothing to do with the number of bits in the addresses.
makes no difference considering that the OP was asking what the difference between 64 bit and 32 bit for mac os X. And the main difference is address space. 32 bit macs can only use 3gb RAM. 64 bit macs can use a huge amount.
in any case the theoretical limit is still 2^32 bits (4gb for 32 bit), which is obviously somewhat less than 2^64 bits (around 17 billion gb for 64 bit
um no it can't. name a 32bit macintosh which can address more than 3gb of RAM.
kthx
krispie is correct. The limit is governed by the number of memory slots, not by the address space of the processor. Every G5-based Mac was setup to accept at least 2 GB RAM. All Power Mac G5s and are setup to accept at least 4 GB RAM. Late model PM G5s and current Mac Pros can accept up to 16 GB RAM. However, the thing that you don't seem to understand is that MacOS X is not MS-DOS. It is a preemptive, multitasking virtual memory operating system. Applications access memory. Whether the memory is physical RAM or virtual memory, it is all part of a unified memory address space.
krispie is correct. The limit is governed by the number of memory slots, not by the address space of the processor. Every G5-based Mac was setup to accept at least 2 GB RAM. All Power Mac G5s and are setup to accept at least 4 GB RAM. Late model PM G5s and current Mac Pros can accept up to 16 GB RAM. However, the thing that you don't seem to understand is that MacOS X is not MS-DOS. It is a preemptive, multitasking virtual memory operating system. Applications access memory. Whether the memory is physical RAM or virtual memory, it is all part of a unified memory address space.
I'm afraid you are confused. 32 bit architecture means a process cannot use more than 32bit address space. Its that simple. 32 bit address space = 2^32 = 4gb. In other words any 32 bit application can use a maximum of 4gb RAM. 64 bit applications can use a lot more, but you need 64 bit architecture to run it.
Also applications do not simply "access" memory without regard for whether or not its physical or virtual. That would be cripplingly inefficient.
As you noticed, g5s can use 16gb of memory ... because they are 64 bit. G4s were always limited for RAM because they were 32bit. Even if you had enough slots to put 16 gb of RAM in g4, most of it would sit around doing nothing, because any 32 bit application will always be limited to 4 GB RAM.
Bottom line: 64 bits doesn't really get you anything in speed, and only gets you data access capabilities that most people will never use. But, like, it's bigger and stuff.
I dunno, I think a lot of people will find using more than 4gb RAM pretty useful. Some software really chews through RAM
Yes, "some" software chews through RAM. And "most" people don't use it.
k?
k.
99% of the ZOMG! 64bitz! hype that I see is spouted by clueless folks who assume that 64 > 32, therefore it's bettah, it will make their computer run faster, and angels will come down to trumpet their way to glory.
64 bits, right now, is strictly useful for folks who deal with extremely large datasets. For anyone else, it's somewhere between complete overkill and the geek version of the penis extension sports car. Bottom line: if you're not sure if you need it, you don't. It's strictly for future proofing at the moment, and irrelevant for the vast majority of people.
I dunno, I think a lot of people will find using more than 3gb physical RAM pretty useful. Some software really chews through RAM
is there any macs right now that are set up for 64bit?
is there any macs right now that are set up for 64bit?
any g5, core2duo or xeon is 64 bit. worth remembering that the architecture being 64 bit is not enough in itself.. the software has to be written to use it.
Bottom line: if you're not sure if you need it, you don't. It's strictly for future proofing at the moment, and irrelevant for the vast majority of people.
thats true... at present
... 32 bit address space = 2^32 = 4gb. In other words any 32 bit application can use a maximum of 4gb RAM. ...
2^32 memory locations. Last time I checked, there were four (4) bytes in every 32-bit word. Perhaps things are different on your planet.
2^32 memory locations. Last time I checked, there were four (4) bytes in every 32-bit word. Perhaps things are different on your planet.
Mr. Me if you don't believe me then ask Apple:
"the 64-bit Intel Xeon processors can manage the precision needed for floating-point mathematics that express integers up to 18 billion billion. They also allow Mac Pro to surpass the 4GB memory limit of 32-bit processors."
or maybe Apple is wrong too.. after all they only design the OS and the computer
Mr. Me, so you saying we have to do 4^32?
No, I am saying 4 (bytes/word)*2^32 words, which is 2^34 bytes.
To address Archstudent's point, this assumes that memory is addressed 32-bit word by 32-bit word. If it is addressed at the byte level, then the amount of addressable memory is limited to 4 GiB. Archstudent links to an Apple website for his authority. Apple plays a little fast and loose with its language by not specifying which 32-bit processors it is referring to. This Wikipedia page is a little clearer than Apple's.