Advantages of 64 bit OS...???

[kenr77]

I also posted this in the Software/XP forum but have yet to get a reply.

Does Having the OS take advantage 64 Bit hardware make a Difference..??? Does a 64 bit OS run faster than a 32 bit on a 64 bit CPU and MoBo..?? I know the applications that are 32 bit will/should run about the same, I think.? I don't think the 64 bit version of XP cost any more than the 32 bit version. I am considering using an old 32 bit W2k Pro for my new build, but will probably get XP pro for comparison.

Thanks for information.

 

[jackluo923]

Running 64bit OS let use use more than 4gb of ram, let you use 64bit programs, doesn't run 16bit programs which is a good thing because it wipes out most of the virus, isn't compatible with some of the 32bit program, the OS of the future.

If you have a new build, usually 64bit OS will not have compatibility problems. Only the old hardware such as the a 8 year old scanner, 7 year old digital camera, no name brand webcame and other outdated accessories will have compatibility issues.

 

[YO_KID37]

http://www.pcworld.com/article/id,111508-page,1/article.html

This was the first article I read to help me understand 64-bit computing and it's advantages. Explains that it won't make anything faster, only allow you to utilize more memory, if you have it.

 

[udontnome]

Depending on the application, if at the last build of that application register variables are turned on, there will be some speed improvement for most every application, some a huge amount if the code is also adequately profiled. The reason is 64 bit code has access to 16 true general purpose registers where non-64 has only 8 semi-dedicated registers. The following is cut from the Wiki article on amd64 and rather than make the uninitiated dig to find it...

'Additional registers: In addition to increasing the size of the general-purpose registers, the number of named general-purpose registers is increased from eight (i.e. eax,ebx,ecx,edx,ebp,esp,esi,edi) in x86-32 to 16. It is therefore possible to keep more local variables in registers rather than on the stack, and to let registers hold frequently accessed constants � this should be a significant area of speed improvement for software with computationally intensive deeply nested loops; arguments for small and fast subroutines may also be passed in registers to a greater extent.'

This doesn't even refer to stack frames which are huge clock stealers that a competent programmer could easily minimize with the profiler.

A look at the x86 register file - http://www.electronics.dit.ie/staff/tscarff/8086_registers/8086_registers.html

Both refer to the x86 registers as general purpose. They are anything but, mostly dedicated though some are not as much as others. 64 bit registers are truly general (exceptions of course being stack and instruction pointer), meaning any register can be used to do anything any other one can. AMD added the additional 8 registers with their 32 bit processors.

 

[MU_Engineer]

I also posted this in the Software/XP forum but have yet to get a reply.

That's a lot less heavily trafficked than the CPU forum is.

Does Having the OS take advantage 64 Bit hardware make a Difference..??? Does a 64 bit OS run faster than a 32 bit on a 64 bit CPU and MoBo..??

That all depends. A 64-bit OS always has three advantages over a 32-bit OS:

1. It lets you use more than ~3.3 GB RAM.
2. The code can be compiled with much better optimizations than generic i686 code can be without risking incompatibility with certain older processors. SSE2 particularly comes to mind here.
3. Integers are by default 8 bytes rather than four. This makes some math applications more efficient and gets rid of the need to explicitly compile programs with large file support to make >2 GB files. This isn't really an issue unless you code...and then it can be a real help.

It also always has one disadvantage: 64-bit code will always use more RAM than 32-bit code due to integers and pointers being 8 bytes rather than 4. Many programs use a full 8-byte integer to store single-digit numbers (e.g. loop counters) and less than 1/100 millionth of the storage capacity of the variable is used. This leads to more bloat.

Other than that, your experiences will vary OS to OS and program to program. Hardware support varies widely by OS for 64-bit support. Linux has 99.9999% of the same hardware and software supported in x86_64 as it does in 32-bit x86, but 64-bit builds of Windows have far fewer drivers and programs available than the 32-bit builds. Solaris has pretty decent x86_64 support, and I hear the BSDs do as well.

I know the applications that are 32 bit will/should run about the same, I think.? I don't think the 64 bit version of XP cost any more than the 32 bit version. I am considering using an old 32 bit W2k Pro for my new build, but will probably get XP pro for comparison.

32-bit applications will run just fine on most x86_64 OSes. The only thing that's required is multilib support so that a 32-bit program keeps its 32-bit libraries separate from 64-bit libraries. Windows has this and so do most UNIX-type OSes, at least by default. You can have a purely 64-bit system on a UNIX-type OS if you install it without 32-bit library support (which means no "lib32" folder, analogous to no "i386" folder in Windows.)

Your suggestion to use Windows 2000 is a good one, provided that you do not want to run more than 3 GB of RAM and have hardware that has Windows 2000 drivers. Most stuff that will run on XP will work on 2000 as well, but a lot of hardware that's sold for use with Vista by OEMs (particularly laptops) do not have XP or 2000 drivers. Caveat emptor.

 

[deerhunter716]

I will have 4 GB of RAM in my new rig. If I go with 32 bit does that mean ONLY 3.3 GB or so will only be used and the rest of it is not used at all?

I will be running Vista Home Premium.

 

[MarkG]

I will have 4 GB of RAM in my new rig. If I go with 32 bit does that mean ONLY 3.3 GB or so will only be used and the rest of it is not used at all?

The 3GB limit is per application; other applications or the operating system will be able to use the rest of the memory.

 

[deerhunter716]

So basically if I am gaming and have Zone Alarm Internet Security Suite in the background; then theoretically the game could use 3 GB while the OS and Zone Alarm use the other 1 GB?

Are their games that use more than 3 GB of RAM or is that a rarity? My new pc will be only for gaming so trying to decide on 32 vs. 64 bit. Thanks a ton.

 

[elbert]

I will have 4 GB of RAM in my new rig. If I go with 32 bit does that mean ONLY 3.3 GB or so will only be used and the rest of it is not used at all?

I will be running Vista Home Premium.

Could mean you have even less as 3.3 as the best you can get. A GPU with a lot of memory could bring you crashing all the way down to 2.5GB's. Many things are counted in on this not just your GPU's memory. Your CPU's cache, thumb drives, and so on with just about everything with volatile memory counted.

 

[zenmaster]

1) 3.3 is not the best you can get. 3.5Gb is common.

2) It is nothing to do with "Volatile Cache Space" or anything to do with cache. It's work space for drivers. Popping the Thumb drive into Windows does not drop memory. In fact my System with onboard video and the one with the 512mb video card both show 3.5Gb available.

You only see the large drop in memory to the 2.5gb you mentioned with SLI configurations. I'm not sure who wrote the SLI drivers, but they clearly are woeful.

 

[bboysil]

What is "volatile cache"? As i see it it is some cache in the ram, but which devices use it and how?

 

[Hatman]

Its better because you can use lots of ram which is always good, ya never got enough ram!

Tbh i dont know why ya shouldnt use 64bit OS, I've used it for 4 - 5months now and the only drivers issues Ive found are wireless networks, they dont hardly work at all, but that was solved by a £5 cable and a couple of staples.


All games I have tried have worked on it...I actually think all therse driver problems were invented by guys who hated 64bit for some odd reason, heh.

 

[zenmaster]

Just a slight misquote on the previous poster's term of "Volatile Memory".

It's tough to answer your question because it does not apply in the least to this thread. Plugging in Cameras, Thumb Drives, Swapping Video Cards with different amount of memory, etc.. etc.. etc... all have nothing to do in the least with the available memory to Windows.

In essence, there is always some "dead" memory space in Windows XP 32-bit addition and Vista 32-Bit editions just below 4gb. Windows and the Hardware devices reserve logical space of for addressing hardware. This logical space is used in the same fashion regardless if there is physical memory there. The physical memory in that location is just not used for any purpose.

Disabling Hardware devices such as USB Buses (Not unplugging USB Devices), AGP Slot, etc.. etc... may yield more memory but not always and usually not a difference maker if it does. The amount of memory available is usually between 3.2-3.5Gb but the number varies and often depends upon the MB and Bios. Systems with SLI tend to really require alot of scratch space and the amount of memory is well below 3gb in most cases.

As a result, dont consider 4gb and SLI unless you are going to a 64-bit OS.
Pick one or the other.

If not doing SLI, going to 4gb can be worthwhile, just realize that you will not get all 4gb and that most folks do not need it but some may if they are doing things such as virtualization and/or serious graphic artist type of work.

 

[elbert]

1) 3.3 is not the best you can get. 3.5Gb is common.

2) It is nothing to do with "Volatile Cache Space" or anything to do with cache. It's work space for drivers. Popping the Thumb drive into Windows does not drop memory. In fact my System with onboard video and the one with the 512mb video card both show 3.5Gb available.

You only see the large drop in memory to the 2.5gb you mentioned with SLI configurations. I'm not sure who wrote the SLI drivers, but they clearly are woeful.

I'm not sure what volatile cache space is but I can guess its cache that losses it data when power is lost.

Here is M$ reason for 32bit not using passed 3.12GB's of RAM.

For example, if you have a video card that has 256 MB of onboard memory, that memory must be mapped within the first 4 GB of address space. If 4 GB of system memory is already installed, part of that address space must be reserved by the graphics memory mapping. Graphics memory mapping overwrites a part of the system memory. These conditions reduce the total amount of system memory that is available to the operating system.

The reduction in available system memory depends on the devices that are installed in the computer. However, to avoid potential driver compatibility issues, the 32-bit versions of Windows Vista limit the total available memory to 3.12 GB. See the "More information" section for information about potential driver compatibility issues.

If a computer has many installed devices, the available memory may be reduced to 3 GB or less. However, the maximum memory available in 32-bit versions of Windows Vista is typically 3.12 GB.

Just like the video cards memory the CPU's cache over writes a small part of the memory map for system memory. Many other devices also use memory mapping space and are generally of the volatile nature. Some even like the bios also must be included.

http://support.microsoft.com/kb/929605

 

[zenmaster]

Nice Quote, but the poster was writing about XP not Vista.
Yes, Vista is lower than XP. But in no Windows OS is the limit 3.3gb as you stated.

Additonally, the bold highlights were added by you to add emphasis where it did not in the original artical.

The memory mapping for video cards is not dependent upon video memory on the card. 128mb, 256, 512..... it would use the same amount of memory. There is actually a very small chunk of reserved space that is used to relay memory to/from the card. I still remember the days when you manually set those communication locations and sizes.

Have you ever used a system with 4Gb of memory?

You have actually witnessed available memory drop as you add in the thumb cards? Simply put, it does not happen. The OS at boot reserves memory for USB communication. It does not matter what is hooked to that device or if that device has any form of memory itself. It does not even matter if nothing is ever connected to the USB device.

 

[elbert]

Nice Quote, but the poster was writing about XP not Vista.
Yes, Vista is lower than XP. But in no Windows OS is the limit 3.3gb as you stated.

Additonally, the bold highlights were added by you to add emphasis where it did not in the original artical.

The memory mapping for video cards is not dependent upon video memory on the card. 128mb, 256, 512..... it would use the same amount of memory. There is actually a very small chunk of reserved space that is used to relay memory to/from the card. I still remember the days when you manually set those communication locations and sizes.

Have you ever used a system with 4Gb of memory?

You have actually witnessed available memory drop as you add in the thumb cards? Simply put, it does not happen. The OS at boot reserves memory for USB communication. It does not matter what is hooked to that device or if that device has any form of memory itself. It does not even matter if nothing is ever connected to the USB device.

I use systems all the time with more than 4GB's of RAM as I build systems. Memory mapping for video cards use the same amount if not more for the GPU's memory. SLI isnt needed just pop in a 1GB HD2900XT and restart to a big lose in RAM.

For example, if you have a video card that has 256 MB of onboard memory, that memory must be mapped within the first 4 GB of address space. If 4 GB of system memory is already installed, part of that address space must be reserved by the graphics memory mapping. Graphics memory mapping overwrites a part of the system memory. These conditions reduce the total amount of system memory that is available to the operating system.

Have you witnessed available memory rise from not using a thumb drive? LOL!!! Twisting someones words is fun. I didnt state it dropped by using one. The thumb drives drivers takes space away from memory mapping like you state just not the GPU. A thumb drive isnt volatile and doesnt need the whole space mapped unlike the GPU.

Please a notable link showing that small chunk of memory used for GPU memory.

 

[djgandy]

One word(well actually 3). DMA.

And 64bit pointers are not 8 bytes long. There was no point making them that long so I think they ended up making them 40bits.