This is the biggest advantage of a 64-bit system, which can use more than 4GB of memory. Most new desktops and laptops have at least 4GB of memory. The problem is that 32-bit versions like Vista and Win 7 can only use about 3GB of memory. In contrast, 64-bit Windows can not only use up to 192GB of memory, but also use memory mapping instead of BIOS functions, so that the operating system can really use all 4GB. So, if you install Win7 x64, you won't waste 1GB of memory for a machine with 4GB of memory.

Personally, I think it is only a matter of time before 3GB is not enough for daily use. Win 7' s XP mode function is an example, which allows you to run old applications on a virtual machine in Windows XP. This function can be used for many purposes, such as running Office 2007 and Office 2003 on the same computer at the same time, or IE (useful for WEB development). WinXP mode needs at least 5 12MB ~ 1GB of memory to run normally, so XP mode is very memory-consuming. So if you deploy Windows 7 32-bit now, you may migrate to 64-bit soon, just because you need to upgrade your machine and new memory. My own laptop has 8GB of memory, because the programs developed for me can run in every virtual machine environment. I don't want to waste every byte in memory.

Can 64-bit really provide better performance?

I guess many people think that 64-bit processors are faster than 32-bit processors. Because the conversion from 8 bits to 16 bits and from 16 bits to 32 bits does bring some performance improvements. Based on the above reasons, can it be considered that 64-bit processors can be faster?

For example, many 32-bit processors support the S*** instruction set, but most programmers don't use it at all, because it will prevent computers that don't support these instruction sets from running their compiled programs (for example, SSE2 can make Zip compression faster, but none of the three most commonly used compression software is used).

Therefore, only 64-bit programs optimized by 64-bit will have performance improvement. Unfortunately, most Windows applications don't do this optimization.

However, in the last year, many 64-bit applications have been born, but don't make the mistake of thinking that they will be faster than the 32-bit version. Because usually, this 64-bit version is only made because the 32-bit version can't run normally on the 64-bit Windows operating system. However, some programs that have performance dependence on 64-bit, such as mathematical calculation (such as Mathlab) and various video processing software, or software developers explicitly support 64-bit (such as 7zip), the speed may change significantly compared with the 32-bit version.

On the other hand, win64 will not degrade the performance of the computer. Although similar to CLR (. Net) will do some calculations to make 32-bit programs run on 64-bit systems, which logically takes more time. However, in practice, you won't know the difference. Almost all performance tests can prove that the performance difference between 64-bit and 32-bit can be ignored in most cases.

Therefore, better CPU performance is not the reason to upgrade to 64-bit.

But there is no doubt that this phenomenon is likely to change soon, and the future belongs to 64. As time goes by, more and more software vendors will provide 64-bit versions of programs. In particular, Microsoft Office 20 10 will also have a 64-bit version. But the performance of 64-bit Excel and Access is unknown.

Software compatibility

When Vista was released, many independent software developers (ISVs) were not ready. Due to the huge structural changes, many applications cannot run normally on Vista. At that time, most organizations thought that the transition to vista would only bring more trouble. Similarly, Vista 64-bit will only bring more trouble.

However, Win7 is different. Compared with Vista, Win 7 has no major structural changes, and all programs that can run normally under Vista can run normally under Win 7. Meanwhile, software developers have revised the compatibility of their software with vista. This means that for 32-bit systems, compatibility is no longer a problem for Win 7.

Of course, there are still risks, and the compatibility of software is still the weakness of 64-bit, but it is certain that the probability of incompatibility should be much lower than that of Vista 64-bit. Because vista needs more and more memory, it forces a large number of users to use 64-bit systems, which allows software developers to receive feedback and improve 64-bit compatibility.

If you are not sure whether the software can run on a 64-bit system, you can use VMware or VirtualBox first to determine the compatibility of these softwares. Because some enterprise programs are still 16-bit, 16-bit applications and MS-DOS programs cannot run under a 64-bit system.

Knowledge points: WOW 64 (Windows 64 bit on Windows) MSDN

For a 32-bit system, the DLL library needed for program running is stored under Windows\System32 of C:\, while for a 64-bit system, the 32-bit library is stored under Windows\SysWow64 of C:\. When a 32-bit program tries to load a library from system32, WOW64 is responsible for redirecting it. The same applies to the registry. WoW64 redirects HKLM \ software to HKLM \ software \ wow 6432 node. Compared with other virtualization mechanisms, WoW64 can ensure software compatibility. Usually, these redirections work well. However, any complex layer may cause unforeseen problems, and the performance of this problem is incompatibility.

hardware compatibility

Hardware compatibility is similar to software. Now most Vista-enabled devices can be safely used in Win 7. Microsoft is well aware that the failure of Vista marketing is mainly a compatibility problem and will not make the same mistake again. Most test reports show that devices that transition to Vista will also smoothly transition to Win7.

However, the drivers of some very old devices are no longer updated (mostly sound cards). Because 32-bit drivers cannot be used in 64-bit systems, the probability of hardware incompatibility in 64-bit systems is higher than that in 32-bit systems.

As for new hardware, all manufacturers will release 64-bit available drivers unless they want to go out of business.

reliability

As you may know, 64-bit Vista device drivers must be digitally signed. You can disable the digital signature checking tool by pressing F8 when turning on the computer, so as to install unsigned drivers on a 64-bit system. However, I think this method is useless. From my own experience, I really can't say that the reliability of 64-bit is higher than that of 32-bit, and I can even see the blue screen caused by the driving device many times. In fact, it is useless to force digital signature.

safe

The signature of the driver improves the security check because it makes the development of rootkit more difficult. In addition, the 64-bit version of Vista and Win7 has two more functions than the 32-bit version, namely, PatchGuard and hardware-based data execution prevention (DEP), but I have never heard that hackers and malware developers are intimidated by these things.

This is a simple fact. Security and reliability are not the reasons for using 64-bit.

Make active

This may be a problem that domestic users don't care much about (=. =), but tell me about it. The serial number of 32-bit Vista cannot activate 64-bit Vista (except the flagship version), but the phenomenon of Win7 has changed, and the retail CD will also contain the 32/64-bit version of Win7. At the same time, only one serial number is needed to activate these two systems. At least so far, the versions of MSDN and TechNet have been confirmed. This is of course a good thing, because you can install a 32/64-bit dual system and switch when you encounter an insoluble compatibility problem.

conclusion

Because of netbooks (SSD is expensive, and some proprietary programs don't support 64-bit), 32-bit systems will continue for a long time, but with the increase of memory requirements of various programs, 64-bit applications will be more extensive. In my opinion. The future must belong to 64. So I think Win 7 64 bit is the choice in most cases. Only when I know that some necessary programs don't support 64-bit will I consider Win7 32-bit, but even so, I will try Xp mode to execute this program first.

Of course, the full text is just a personal opinion, I am not a master.