Giz Explains: What's So Awesome About 64-Bit?

Illustration for article titled Giz Explains: What's So Awesome About 64-Bit?

The phrase "64-bit" has been tossed around lately, the most it's been since the Nintendo 64. If you haven't heard it, pay attention. One of the most important steps forward in computer power is happening right under your nose, but most people don't know thanks to the sneaky efforts of Microsoft and Apple. Though fully 64-bit operating systems are the OSes of tomorrow, you can taste some of that power today with 64-bit versions of Windows and OS X. Here's why 64-bit computing is so awesome:In a word, memory. We're not going to get super nerdy on you here (Wikipedia will gladly go there). To keep it simple, the whole bit thing (16-bit, 32-bit, 64-bit) refers to how much data the computer can keep track of, or talk to, at once, and that's what determines how much memory it can handle. A processor with 32-bit memory addresses can basically roll with 4GB of RAM. A 64-bit system can rock, on the other hand, 16 exabytes of RAM. That's 16.8 bmillion terabytes. Of RAM. You're not going to get that kind of memory, not anytime soon; for now, from a user standpoint, this means there's simply no ceiling to memory expansion. So while 32-bit hardware and software—the current norm in PC-land—limited you to 4GB of RAM (Physical Address Extension will let you have more, but 32-bit software will still only use 4GB), with 64-bit hardware and software, you can use vast amounts of RAM, which enables a whole new world of possibilities for applications, since they'll have a massive amounts of memory to work with. The road to 64-bit rather conveniently dovetails with the multi-core processor arms race, using graphics cards for processing and growth of parallel processing in mainstream computing. In other words, in just a short generation, applications will be able to harness an exponential increase in power over what they can use today—a crapload of processors working together with a smorgasbord of memory at their disposal. With 64-bit, computers can also crunch bigass numbers way faster, so it's excellent for science-y things. So get ready for some cool stuff. You're probably asking: Why not now? I've heard of this 64-bit stuff before. Well, the hardware has been around for a while—64-bit super computers go back decades, and AMD brought 64-bit processors to the mainstream a few years ago with the Athlon 64, for instance. The PowerPC G5 for Macs was also 64-bit. And if you buy a Core 2 Duo today, it's 64-bit. But the operating systems regular people use have essentially been slow to adopt 64-bit until recently, and won't plunge excluslively into 64-bit for another generation, Windows guru Ed Bott explained to us. Windows Vista ships with separate 32-bit and 64-bit editions, with Vista 64-bit being the first consumer-usable 64-bit version of Windows. Apple has been moving more and more of OS X over to a 64-bit architecture with every new version. Bott told us that while Windows 7 will have 32-bit and 64-bit versions, its eventual successor, Windows 8 (or whatever it's called) will likely be the first Windows that's exclusively 64-bit. Reportedly, next year's Mac OS X Snow Leopard will be 64-bit down to the kernel. The reason 64-bit is the future and not the present is that 64-bit is a whole different architecture from the 32-bit status quo—different kernel means different drivers, application compatibility issues, that kind of stuff. A swift, clean break means lots of headaches, especially for the corporate world, which, as Bott told us, is as big of a concern for Microsoft as the consumer space. That's why Apple has been transitioning OS X to total 64-bit over time, and why Microsoft will still ship a 32-bit version of Windows 7. And likely, Bott says, an exclusively 64-bit Windows 8 would have a virtualization setup to run 32-bit apps. "Fortuitously," he told us, "an x64 system with lots of memory should scream at virtualization." Another hitch on the path to true 64-bit glory that Bott raised is the question of "When will people outside of the specialized work software" like Adobe (Photoshop CS4 will be a native 64-bit application in Windows, though not in OS X) write 64-bit apps? With the coming wave of many-core parallel processing and ridiculous amounts of memory to take advantage of, programmers have a lot to play (and deal) with. Applications have to be re-written to take advantage of the multiple cores and huge amounts of memory at their disposable, and that transition is going to take some time. The other slight downside 64-bit Bott mentioned—and it is slight—is that hibernation will be slower, since all that memory means more to write to the hibernation file, and more to read when it wakes up. While that awesomeness sounds like it's too be good to be the norm anytime soon, it's not. Leopard already does quite a bit of 64-bit voodoo, like having a 64-bit GUI and Vista 64-bit is supplanting 32-bit on computer maker's systems, now that the driver situation isn't so abysmal. And while four totally usable gigs of RAM in a Vista machine is a thing of beauty, 6GB and 12GB will quickly become the standard for performance machines with the launch of Intel's Core i7, since it uses triple-channel memory—three delicious sticks of RAM—so 64-bit couldn't come soon enough.



Anyone else remember when that 4GB seemed like an impossibly large number? I remember reading an article about that back when I was running on systems that had all of 4 megabytes of RAM in them, and thinking that there was no way I'd ever need that much memory.

Of course, the new computer I just built has 8GB of RAM in it, so it's running on Vista 64. The driver picture for 64-bit seems to be in a lot better shape now than it was just a year or so ago, and so far everything I've thrown at the thing runs quite fast.