32 bit or 64 bit OS?

It's a common misconception that you need 64 bit applications to run on a 64 bit OS. This is not true.

The only applications that fail to run under the 64 bit version of windows are old 16 bit applications. This can, occasionally, be a problem because even some 32 bit applications had a 16 bit installation program. But it's pretty rare to run into those apps anymore.

If you have a 16 bit application you really need, then there's always running in XP Mode.

Another common myth is that you need 64 bit apps to run well, or that 32 bit apps are significantly slower than their 64 bit counterparts.

This is only true if an an application can benefit from more registers and/or more memory. Databases, for instance, are usually a great candidate for 64 bit. Photoshop is another great 64 bit candidate (and there is a 64 bit photoshop in CS4).

Most apps simply would not be noticably faster as 64 bit, as such there is little to no reason for the authors to create 64 bit versions of them. It's just more work for the author, and twice the maintenance.

Even if you have a 64 bit CPU, you should only run a 64 bit OS if you have more than 3GB of memory. 64 bit applications (including the OS) require more memory to support the larger pointer sizes and data sizes. They use typically 50% more memory than 32 bit apps. So using a 64 bit OS with only 2GB of memory is largely wasting memory. You won't see a huge performance boost, and you will be able to do less because you will run out of memory faster than with a 32 bit OS.

So the simple rule of thumb. Don't install a 64 bit OS unless you have more than 3GB of memory and a 64 bit CPU, or if you plan to upgrade to more than 3GB of memory relatively soon.

golden039 said:

What are the Pros and Cons of a 32 vs. 64 bit OS? It's my understanding that nothing works on a 64 bit OS which will of course use the 64 bit registers of your system. The software just isn't developed for the 64 or is there something I'm missing. I find it hard that the 64 is backwards compatible with the 32 but who knows and that's why I'm asking?

Well, IDK about others but when I installed 64-bit my system CONSTANTLY overheated. Due to this reason, I switched to 32-bit and since then my system has never overheated. Not even when Playing Crysis on Very high settings, no lag.

gamepro127 said:

Well, IDK about others but when I installed 64-bit my system CONSTANTLY overheated. Due to this reason, I switched to 32-bit and since then my system has never overheated. Not even when Playing Crysis on Very high settings, no lag.

That's strange. Your OS being 64-bit wouldn't cause hardware to overheat. What overheated exactly? Processor? Video card? What type of hardware do you have?

DataMan47 said:

The memory overhead is not nearly that high. Yes, there is an extra memory overhead in the world of 64, and it comes from these three sources:

I misspoke when I said "typically", rather than "as much as". However it really depends on the kind of app. Some apps use a lot of pointers, and thus use significantly more memory than 32 bit versions.

You are of course correct that the WOW64 layer is one of the larger culprits.

However, that doesn't change my recommendation. A 64 bit OS still uses a significantly larger amount of memory than a 32 bit OS. You can see this just by looking at the amount of memory in use on the same computer with both 32 and 64 bit OS's installed.

In my experience, a 32 bit version of 7 uses about 800MB right after bootup and login, while a 64 bit Windows 7 uses about 1.2GB. What's more, my common application usage has me running about about 2.5GB of memory in use on a 64 bit OS, while i'm still well below 2GB (and closer to 1.5GB) on a 32 bit OS.

This is on a computer with 4GB of memory.

I see no real benefit from running a 64 bit OS with only 3GB. You use more memory, and even if you're only using about 1-2GB of memory, you will end up with less memory available for disk and system cacheing, thus reducing overall performance.

64 bit is a no-brainer with 4GB or more, it's the only way to use all your memory.

I am impressed by the expertise of the folks here. I have been running Windows 7 ultimate edition 64-bit since about October. I have successfully run a number of 32-bit applications. I am trying to sort of figure out how to 64-bit Windows deals with memory. The main reason is that I am using Dragon NaturallySpeaking 10.0 preferred which is a voice-recognition package. It is known that this will temporarily freeze when it runs out of memory. Sometimes it returns a report that it is attempting to recover from low system resources.


I am using one of the desktop gadgets-All CPU-which monitors all four cores of my quad processor as well as the portion of my 8 GB of memory which is being used.


Recently Dragon has been locking up quite a bit. This would start when I opened an application such as Internet Explorer and then I ran into some flash video or open several pages quickly. I realize that this started when I began to allow Skype to load it Windows startup. My experience with Skype has suggested that it is quite a memory hog.



While unloading Skype has corrected the problem short term I noticed that during the hangups my little desktop application indicated that less than 50% of my memory was being used at the processors are barely running at all. On the face of it this would seem to contradict my analysis that resources were being overused during the hangups -- although I think I have found that that is the case
.

Within the above context I'm curious about the basics of how a 64-bit operating system handles 62 bit applications? I realize there may not be a straightforward layman's explanation.

Do 32-bit applications have access to more memory in a 64-bit operating system or are they still constrained as they would be on a 32-bit operating system. While Dragon is approved for 64-bit operating systems I believe it is a 32-bit application. At least the installer does not ask which version to load and the setup application is the same for either OS.

Do 32-bit applications compete with other 32-bit applications for limited memory or resources?



Just curious. Thank you for a great forum. I did not see any references to these questions on a general basis will would be happy to review those if I missed them.



Kevin

lostsoul62 said:

I find it hard that the 64 is backwards compatible with the 32 but who knows and that's why I'm asking?

Been under a rock for the past three years? Vista x64 made x64 OSes safe for mainstream use, over three years ago. It seems rare these days, especially on some enthusiast forums, to see anyone running an x86 version of Windows 7.

It honestly begs the question...if an x64 OS wasn't compatible with common software...why would so many people be running it, and doing so without issue?

kbrady said:

I am trying to sort of figure out how to 64-bit Windows deals with memory. The main reason is that I am using Dragon NaturallySpeaking 10.0 preferred which is a voice-recognition package. It is known that this will temporarily freeze when it runs out of memory. Sometimes it returns a report that it is attempting to recover from low system resources.

In Windows, the term "System Resources" does not mean memory, well, it does, but not the systems memory.

Windows contains a number of "pools" of memory called "heaps", these heaps are referred to as "System Resources" and refer to areas of memory reserved for graphics objects, fonts, file handles, and window objects. Some kinds of apps use ridiculous amounts of these resources and leave them low for other apps, and when you have several apps that use ridiculous amounts (or have resource leaks), then you run into trouble.

You can have 8GB of memory free and still run out of system resources. This is one of those "annoyances" about the architecture of Windows that we just have to deal with.

The only real solution is to find out what's using all your resources and not run those apps.

F1FAN said:

64 bit is rubbish, after a while it slows down. Start up time was increased by atleast 6 secs for me and i had a few friends with games that worked on 64-bit but not very well at all, to me it still needs work. I have gone back to 32-bit, although i loose a bit of ram, it makes no difference because 64 takes more to run anyway so im using the same percentage as on 64-bit. about 1,15GB in 64, 900MB in 32.

While it's true that 64 bit uses more memoryt han 32 bit (see my response up a bit), there is nothing inherent in the 64 bit OS that will make it slow down, and games should work just as well in 64 bit as 32 bit.

If the system is slowing down, then there is a reason for that, and that reason should be investigated, because I'll guarantee you that whatever it is will also happen in 32 bit.