Windows 7: The 64-Bit Question (original) (raw)

Does it really make a difference whether you're running 32- or 64-bit Windows 7?

ushered in the era of mainstream 64-bit computing—and almost no one realized it. That's because, although 64-bit versions of Windows XP had been available for a while, it was only with Vista that PC manufacturers finally got wise to the fact that practically all the hardware out there was 64-bit compatible. They then passed those capabilities along to their customers—most of whom, through no fault of their own, probably couldn't tell a bit from a byte, let alone 64 of them from 32. But now that is out, in retail versions that include both 32- and 64-bit discs, the question is more relevant than it's ever been: Do you need a 64-bit OS?

The answer is simple: Yes.

Okay, maybe the real answer is a little more complex than that. Technically, you probably don't need one. You'll be hard-pressed to find any software, whether from a major or a minor vendor, that doesn't come in a 32-bit version. And even most tech professionals would have trouble telling the difference between a 32- and a 64-bit app under many situations. But 64-bit software gives you options and performance that 32-bit software doesn't—and to take advantage of them, you need a 64-bit OS.

The biggest, most immediate advantage comes in terms of memory. A 32-bit system is limited to utilizing 4GB of RAM (232 addresses). Actually, it's closer to 3.25GB, because a portion of that RAM is reserved for use by the BIOS, the PCI and PCI Express buses, and so on. But with a 64-bit system, which has 264 memory addresses, your computer can spend less time swapping processes into and out of physical memory—which results in major performance boosts in software that supports it. The theoretical maximum of ram that a 64 bit OS can address is 16 exabytes, or about 16 billion GB, but Microsoft currently puts a 16TB limit on address space and allows only 128GB of physical RAM. That's still way more than most any user will need—or have.

Of course, this means that if your PC doesn't have—or you don't plan on buying—4GB of memory or more, you're not going to see much practical advantage to running 64-bit Windows. But a 64-bit OS, paired with a large amount of memory (6GB or 12GB are common capacities with motherboards that take advantage of the newer triple-channel memory technology), can make a huge difference in 64-bit software. One of the most common consumer examples is , but 64-bit support is becoming increasingly prevalent in apps that need to run a lot of complex, processor-intensive tasks.

There are some potential downsides to using 64-bit Windows. You need 64-bit device drivers, which may not be available for all your hardware. There's also the requirement than all device drivers must be digitally signed, which could also be a problem. And although most 32-bit apps will probably work on 64-bit Windows, not all will. This may require you to find 64-bit versions of those programs or use other software altogether. You might also try Windows on Windows 64 (WoW64) is an emulator designed to let you natively run 32-bit software within a 64-bit Windows 7 installation.

Support for 64-bit has skyrocketed in recent years—it's had to, since so many computer buyers were using it, whether they knew it or not—so the chances you'll run into any difficulties are slim. So if you have the proper hardware, 64-bit Windows is definitely the way to go. There's just one potential wrinkle, and it only affects upgraders: You can't do an in-place upgrade from 32-bit Vista to 64-bit Windows 7, so if you have that version of Vista, you'll need to do a clean install to squeeze every possible drop of performance out of Windows 7. But if you plan on using powerful applications today and tomorrow, that inconvenience could well be worth it.