64-Bit Computing
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
computer science crazy
Super Moderator

Posts: 3,048
Joined: Dec 2008
22-09-2008, 10:47 AM

The question of why we need 64-bit computing is often asked but rarely answered in a satisfactory manner. There are good reasons for the confusion surrounding the question.That is why first of all; let's look through the list of users who need 64 addressing and 64-bit calculations today: oUsers of CAD, designing systems, simulators do need RAM over 4 GB. Although there are ways to avoid this limitation (for example, Intel PAE), it impacts the performance. Thus, the Xeon processors support the 36bit addressing mode where they can address up to 64GB RAM.

The idea of this support is that the RAM is divided into segments, and an address consists of the numbers of segment and locations inside the segment. This approach causes almost 30% performance loss in operations with memory. Besides, programming is much simpler and more convenient for a flat memory model in the 64bit address space - due to the large address space a location has a simple address processed at one pass. A lot of design offices use quite expensive workstations on the RISC processors where the 64bit addressing and large memory sizes are used for a long time already. oUsers of data bases.

Any big company has a huge data base, and extension of the maximum memory size and possibility to address data directly in the data base is very costly. Although in the special modes the 32bit architecture IA32 can address up to 64GB memory, a transition to the flat memory model in the 64bit space is much more advantageous in terms of speed and ease of programming. oScientific calculations. Memory size, a flat memory model and no limitation for processed data are the key factors here. Besides, some algorithms in the 64bit representation have a much simpler form. oCryptography and safety ensuring applications get a great benefit from 64bit integer calculations.

The labels "16-bit," "32-bit" or "64-bit," when applied to a microprocessor, characterize the processor's data stream. Although you may have heard the term "64-bit code," this designates code that operates on 64-bit data. In more specific terms, the labels "64-bit," 32-bit," etc. designate the number of bits that each of the processor's general-purpose registers (GPRs) can hold. So when someone uses the term "64-bit processor," what they mean is "a processor with GPRs that store 64-bit numbers." And in the same vein, a "64-bit instruction" is an instruction that operates on 64-bit numbers. In the diagram above black boxes are code, white boxes are data, and gray boxes are results. The instruction and code "sizes" are not to be taken literally, since they're intended to convey a general feel for what it means to "widen" a processor from 32 bits to 64 bits.

Not all the data either in memory, the cache, or the registers is 64-bit data. Rather, the data sizes are mixed, with 64 bits being the widest. Note that in the 64-bit CPU pictured above, the width of the code stream has not changed; the same-sized opcode could theoretically represent an instruction that operates on 32-bit numbers or an instruction that operates on 64-bit numbers, depending on what the opcode's default data size is. On the other hand, the width of the data stream has doubled. In order to accommodate the wider data stream, the sizes of the processor's registers and the sizes of the internal data paths that feed those registers must be doubled.

Now let's take a look at two programming models, one for a 32-bit processor and another for a 64-bit The registers in the 64-bit CPU pictured above are twice as wide as those in the 32- bit CPU, but the size of the instruction register (IR) that holds the currently executing instruction is the same in both processors. Again, the data stream has doubled in size, but the instruction stream has not. Finally, the program counter (PC) has also doubled in size.
For the simple processor pictured above, the two types of data that it can process are integer data and address data. Ultimately, addresses are really just integers that designate a memory address, so address data is just a special type of integer data. Hence, both data types are stored in the GPRs and both integer and address calculations are done by the ALU.Many modern processors support two additional data types: floating-point data and vector data. Each of these two data types has its own set of registers and its own execution unit(s).

Report to moderator
Use Search at http://topicideas.net/search.php wisely To Get Information About Project Topic and Seminar ideas with report/source code along pdf and ppt presenaion
Rupesh Chouksey
Active In SP

Posts: 1
Joined: May 2011
03-05-2011, 02:14 PM


Important Note..!

If you are not satisfied with above reply ,..Please


So that we will collect data for you and will made reply to the request....OR try below "QUICK REPLY" box to add a reply to this page

Quick Reply
Type your reply to this message here.

Image Verification
Please enter the text contained within the image into the text box below it. This process is used to prevent automated spam bots.
Image Verification
(case insensitive)

Possibly Related Threads...
Thread Author Replies Views Last Post
  difference between soc and aoc in mobile computing jaseelati 0 341 20-12-2014, 01:12 PM
Last Post: jaseelati
  Cloud Computing abstract seminar tips 4 5,292 20-06-2014, 03:40 PM
Last Post: s.vmurugan@yahoo.com
  Towards Secure and Dependable Storage Services in Cloud Computing FULL REPORT seminar ideas 5 4,152 24-03-2014, 02:51 PM
Last Post: seminar project topic
  Introduction to Cloud Computing project uploader 4 4,675 22-03-2014, 05:27 PM
Last Post: navasfiroz
  Green computing; balancing energy in processing, storage, and Transport PPT seminar projects maker 0 520 26-09-2013, 04:09 PM
Last Post: seminar projects maker
  Report on Autonomic Computing  seminar projects maker 0 419 19-09-2013, 04:44 PM
Last Post: seminar projects maker
  Perceptive Computing ppt seminar projects maker 0 342 19-09-2013, 04:11 PM
Last Post: seminar projects maker
  Mobile Learning (mLearning) Based on Cloud Computing: mLearning as a Service (mLaaS) seminar projects maker 0 472 11-09-2013, 03:40 PM
Last Post: seminar projects maker
  Pervasive Computing: Vision and Challenges pdf study tips 0 417 14-08-2013, 02:58 PM
Last Post: study tips
  Green Cloud Computing in Developing Regions pdf study tips 0 457 12-08-2013, 04:59 PM
Last Post: study tips