[ACCEPTED]-What are the advantages of a 64-bit processor?-cpu

Accepted answer
Score: 34

There's a great article on Wikipedia about the differences and benefits 3 of 64bit Intel/AMD cpus over their 32 bit 2 versions. It should have all the information 1 you need.

Some on the key differences are:

  • 16 general purpose registers instead of 8
  • Additional SSE registers
  • A no execute (NX) bit to prevent buffer overrun attacks
Score: 24

The main advantage of a 64-bit CPU is the 40 ability to have 64-bit pointer types that 39 allow virtual address ranges greater than 38 4GB in size. On a 32-bit CPU, the pointer 37 size is (typically) 32 bits wide, allowing 36 a pointer to refer to one of 2^32 (4,294,967,296) discrete 35 addresses. This allows a program to make 34 a data structure in memory up to 4GB in 33 size and resolve any data item in it by 32 simply de-referencing a pointer. Reality 31 is slightly more complex than this, but 30 for the purposes of this discussion it's 29 a good enough view.

A 64-bit CPU has 64-bit 28 pointer types that can refer to any address 27 with a space with 2^64 (18,446,744,073,709,551,616) discrete 26 addresses, or 16 Exabytes. A process on 25 a CPU like this can (theoretically) construct 24 and logically address any part of a data 23 structure up to 16 Exabytes in size by simply 22 de-referencing a pointer (looking up data 21 at an address held in the pointer).

This 20 allows a process on a 64-bit CPU to work 19 with a larger set of data (constrained by 18 physical memory) than a process on a 32 17 bit CPU could. From the point of view of 16 most users of 64-bit systems, the principal 15 advantage is the ability for applications 14 to work with larger data sets in memory.

Aside 13 from that, you may get a native 64-bit integer 12 type. A 64 bit integer makes arithmetic 11 or logical operations using 64 bit types 10 such as C's long long faster than one implemented 9 as two 32-bit operations. Floating point 8 arithmetic is unlikely to be significantly 7 affected, as FPU's on most modern 32-bit 6 CPU's natively support 64-bit double floating 5 point types.

Any other performance advantages 4 or enhanced feature sets are a function 3 of specific chip implementations, rather 2 than something inherent to a system having 1 a 64 bit ALU.

Score: 3

This article may be helpful:


This one is 3 a bit off-topic, but might help if you plan 2 to use Ubuntu:


And this pdf below contains 1 a detailed technical specification:


Score: 2

Slight correction. On 32-bit Windows, the 13 limit is about 3GB of RAM. I believe the 12 remaining 1GB of address space is reserved 11 for hardware. You can still install 4GB, but 10 only 3 will be accessable.

Personally I think 9 anyone who hasn't happily lived with 16K 8 on an 8-bit OS in a former life should be 7 careful about casting aspersions against 6 some of today's software starting to become 5 porcine. The truth is that as our resources 4 become more plentiful, so do our expectations. The 3 day is not long off when 3GB will start 2 to seem ridiculously small. Until that day, stick 1 with your 32-bit OS and be happy.

Score: 1

About 1-3% of speed increase due to instruction 1 level parallelism for 32-bit calculations.

Score: 1

Just wanted to add a little bit of information 1 on the pros and cons of 64-bit CPUs. https://blogs.msdn.microsoft.com/joshwil/2006/07/18/should-i-choose-to-take-advantage-of-64-bit/

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