By Michael Lasky

Even though 64-bit PCs have been available for seven years, the promise of 64-bit computing has been delayed by a dearth of 64-bit software.

The situation is improving — slowly — but many major PC applications remain 32-bit affairs.

Microsoft likes to boast about the extra performance delivered by the 64-bit versions of Windows. Likewise, PC vendors continue to pitch the benefits of 64-bit PCs over their 32-bit brethren.

That’s all well and good — and theoretically true — but without software optimized for 64-bit machines, using those more-advanced processors for everyday tasks is like running a Formula One race car on regular gas.



The primary difference between 32-bit applications and their 64-bit counterparts is the size of memory the programs can address. Computers use only two digits (ones and zeros), so a 32-bit program can track 2^32 (2 to the 32nd power) memory addresses — about 4GB. This is the basis of the “4GB memory limit” for 32-bit hardware and software.

A 64-bit PC can track 2^64 addresses, yielding a theoretical memory ceiling of about 16 exabytes — 16 billion gigabytes. Of course, no PC can hold that much physical memory — but the point is, they could. Similarly, 64-bit software is capable of managing truly huge data sets.

The 64-bit flavor of Windows takes advantage of this. For example, the 64-bit version of Windows 7 Ultimate can address up to 192GB of RAM. More prosaically, 64-bit Windows can routinely allocate up to 4GB (and sometimes more) to each software process running on the PC. In contrast, 32-bit Windows XP maxes out at 2GB per process.

There are other differences, too; for more information, see the Nov. 19, 2009, Best Software column by Gizmo Richards, “Should you move to 64-bit Windows 7?” (paid content).

Big-name apps remain MIA from 64-bit list

General-purpose PCs using 64-bit processors emerged in 2003. To this day, however, 64-bit versions of such major applications as MS Office, Adobe Photoshop, Web browsers, and security suites have been vaporware. Also, finding 64-bit drivers for your PC’s peripherals has been like playing the digital equivalent of “Where’s Waldo?” — and in many cases, Waldo is nowhere to be found.

That’s the main reason why 64-bit PCs haven’t eighty-sixed 32-bit systems just yet. Sure — a quick Web search will uncover a bunch of 64-bit apps, and 64-bit shareware sites abound. These include the Catalogue of 64-bit Software and X64-bit Download, which offers the Microsoft Office 2010 beta release designed for 64-bit Vista and Windows 7, as well as 64-bit drivers, security apps, and system utilities.

Unfortunately, existing 32-bit ActiveX controls — whether from Microsoft or third parties — are incompatible with the 64-bit version of Office 2010, as described in the MSDN Office Developer Center.

Despite these and similar download sites, most of the 64-bit software available for Vista and Windows 7 is composed of shareware utilities and low-rent productivity packages.

A 64-bit IE, but minus 64-bit ActiveX controls

Microsoft released the 64-bit version of Internet Explorer 8 in early 2009; the program is available from the Microsoft Download Center. However, the program is in dire need of a Daddy Warbucks — it’s orphaned by the lack of native 64-bit ActiveX controls and other Web objects.

Mozilla’s Firefox browser has been available in 64-bit versions since release 3.5; visit the Firefox download page for the link. Note that Firefox is currently up to version 3.6, with a prerelease 3.7a version also available.

Google offers a 64-bit version of its Chrome browser (available from X64-bit Download), but only for Linux; the company hasn’t yet announced a date for 64-bit Chrome for Windows.

The apps benefiting most from a 64-bit architecture are those with large data sets — such as image and video editors and other graphics apps, whose files can be massive. Photoshop users are left wondering why it has taken Adobe so long to release a 64-bit version of the popular image-editing app.

According to an Aug. 21, 2009, blog post by Adobe Photoshop principal product manager John Nack, the main benefit of 64-bit software is its ability to address larger amounts of memory. This is particularly noticeable when working with large image files; Nack claims Adobe’s testing resulted in a performance improvement of 8% to 12% when running Photoshop in 64-bit mode.

However, to take advantage of 64-bit processing, users need to allocate more than 4GB RAM solely to Photoshop, according to Nack’s Aug. 21, 2009, post, “A 64-bit reality check.” That means you would need much more system memory than most PCs ship with today.

While we await release of the 64-bit version of Photoshop, Adobe Labs is offering a developer prerelease version of Flash Player for 64-bit Linux and Mac OS. Unfortunately, there’s no indication of when the Windows version of the 64-bit Flash Player will be available.

Most PC software vendors are wary of incurring the high costs associated with developing and marketing 64-bit versions of their products, primarily because few of today’s 64-bit systems ship with sufficient RAM for consumers to realize a benefit from the shift to 64-bit computing. For now, that powerful 64-bit lion on your desktop or in your lap will have the roar of a kitten.

Have more info on this subject? Post your tip in the WS Columns forum.

WS contributing editor Michael Lasky is a freelance writer based in Oakland, California, who has 20 years of computer-magazine experience, most recently as senior editor at PC World.

Related posts:

1. Microsoft continues to make patching harder
2. Free downloadable eBook of Photoshop techniques
3. An entire suite of Windows software for free
4. Run Microsoft Office under Linux
5. Wait A Bit With The New ZoneAlarm