Channel Insider content and product recommendations are editorially independent. We may make money when you click on links to our partners. Learn More.

Part I: 64-bit vs. 32-bit Windows
Windows XP Professional x64 edition is clearly not a mainstream product. For example, though you can order Dell Dimension XPS models with XP X64 installed, Dell gives you this rather dire warning when you try to buy a system with the OS installed:

“Peripherals you currently own or plan to purchase in the near future (cameras, printers, MP3 players, handheld devices) will most likely NOT work on a system purchased with Windows XP Professional x64, and some software applications may not work on the x64 operating system.”

Even given this bleak message, we’re still interested in 64-bit Windows XP, particularly for content creation applications and gaming. But we’re also interested in the impact of running 32-bit applications on Windows XP Pro x64.

For this first installation of a two-part series investigating the performance of 64-bit Windows, we loaded up a test system with 2GB of RAM, an Athlon 64 X2 4800+, and a bunch of applications and benchmarks in both 64- and 32-bit flavors. The focus here is on how 64-bit Windows compares with the now venerable 32-bit Windows XP. Next week, we’ll compare how the Athlon 64 X2 4800+ and Intel Pentium 840 Extreme Edition with EM64T architectures, both dual core, perform relative to each other on Windows XP Pro x64 edition. Continued…

The key to running 32-bit applications is something Microsoft dubs WOW64; WOW stands for Windows on Windows. Running 32-bit apps in x64 essentially gives each application its own 4GB of virtual memory space, which isolates it from other applications. So if one 32-bit application locks up, it only affects its memory space, not other running 32-bit apps. Windows x64 itself has a full 16TB (that’s terabytes) of virtual memory address space. The downside, if you can call it that, is that you’ll want to load your system up with as much memory as possible. While we used 2GB in our test systems, 4GB or even 8GB is desirable—assuming your motherboard supports it.

32-bit and 64-bit applications can run side by side, but there are a few gotchas, beyond drivers. For example, if you’re using Internet Explorer, and a 64-bit version of your favorite plug-in isn’t available, you’ll need to run the 32-bit version. The aforementioned driver issue is perhaps the biggest stumbling block, particularly with digital cameras, web cams, and printers. Creative now has official 64-bit drivers for the Sound Blaster line, chipset and integrated networking support is widely available and even RAID drivers can now be found.

On the other hand, installing and running 32-bit apps can occasionally be a chore. A 32-bit application that has any remaining 16-bit code won’t run, because WOW64 doesn’t support any 16-bit code. Also, 32-bit applications and 64-bit applications get their own folders. “Program Files” is reserved for 64-bit apps, while “Program Files (x86)” is for 32-bit software. This will sometimes result in strange installer behavior, as with Steam, Valve Software’s game download application. Steam insisted that the parentheses in “Program Files (x86)” were illegal characters, and refused to install. You can either install Steam into a different folder (e.g., \games\valve) or change the folder name in the installer to “Progra~2\valve”.

Issues like these aside, running 64-bit Windows seems very much like running 32-bit Windows. System stability was excellent on our test bed, and we ran a variety of applications with no crashes. To further avoid possible contention, Windows keeps separate registry hives for 32-bit and 64-bit applications. Let’s take a look at our benchmark and test-bed setup. Continued…

We used our standard dual-core Athlon 64 X2 system in our testing, which consisted of the following configuration:

Component Athlon 64 System
Processor Athlon 64 X2 4800+ at 2.4GHz
CPU cooler Stock AVC
Motherboard and chipset ASUS A8N SLI Deluxe (nForce 4 Ultra SLI chipset)
Memory 2 x 1GB Samsung DDR400, CAS 2.5-3-3-8, Command rate 1T
Graphics Nvidia GeForce 6800GT PCI Express, 77.72 drivers
Hard drive Seagate 7200.7 160GB SATA Drive
Optical drive ATAPI DVD-ROM Drive
Audio Sound Blaster Audigy 2
Operating system Windows XP Professional with SP2 in 32-bit mode or Windows XP Professional x64

We installed an identical pair of 160GB Seagate 7200.7 hard drives, and then set up 32-bit and 64-bit Windows in a dual-boot configuration. Each operating system got its own disk. We used 2x1GB Samsung-labeled DDR400. Note that it’s tough to find low-latency 1GB modules, but the Samsung modules were able to run at a 1T command rate, with CAS latency 2.5. (For more on how memory ratings work, check out Scott Gardner’s article on Memory Technology). Note that 64-bit drivers are available for all the hardware we tested.

We used the following benchmarks and applications in our testing:

  • Cinebench 2003. Cinebench is a benchmark built around Maxon’s Cinema4D modeling and software rendering application. The company has recently released a 64-bit version of the benchmark that runs on Windows XP Pro x64.
  • POV-Ray 3.70 beta 0.8. The POV-Ray freeware software rendering application has been around since the days of MS-DOS. The current 3.70 version for Windows is still a work in progress, but it does support multithreading. It’s also available in a 64-bit version.
  • 3ds Max 7. Note that no 64-bit version of 3ds Max exists today, but it’s popular enough that we wanted to see how it performed on Windows x64. Note that we used both the SPEC APC 3ds Max test and a couple of pure rendering tests. The SPEC test for 3ds Max 7 is much enhanced over the older test supporting version 6, and takes longer.
  • BAPCo’s SYSmark 2004SE. Although this benchmark consists of 32-bit applications, the recently released SE version now runs on Windows XP Pro x64 edition. Based on real applications, the benchmark gives us a taste of how real applications might run on the system. Note that rather than reporting an overall score, we break it down the individual Internet Content Creation and Office Productivity scores.
  • 3DMark05 and PCMark05. While these are synthetic benchmarks, they can yield insights into individual subsystems within the PC.
  • Five 32-bit games, including Half-Life 2, Flight Simulator 2004, Painkiller, Doom 3, and Unreal Tournament 2004.
  • One 64-bit game, Far Cry. We ran the 32-bit version, the 64-bit vanilla version and the 64-bit enhanced version. The enhanced version adds additional content and detail to the game.

We wanted to answer a couple of questions:

  • What’s the performance penalty (if any) for running 32-bit apps on Windows x64?
  • What’s the net gain, if any, of running a 64-bit version of an application?

Given the limited number of 64-bit tests, we couldn’t reach a definitive conclusion, but we can get some clues as to possible future benefits. Let’s take a look at the test results. Continued…

SYSmark uses a set of real-world applications scripted to behave the way real users would run the apps. Domain experts are consulted to create the test scripts for the benchmark.

Note that the two results are nearly identical. There seems to be little if any penalty in running standard office and content-creation applications in Windows 64-bit edition. Continued…

PCMark is a synthetic test that looks at individual subsystems. Here, we take a look at the CPU and memory scores.

The CPU score under 32-bit Windows was higher by a small but noticeable amount, but the memory scores didn’t shift at all. Continued…

Let’s take a look at POV-Ray, Cinebench, and 3ds Max results.

The SPECapc test seems to indicate that 3ds Max 7 users might see diminished performance relative to running in 32-bit mode. But pure rendering doesn’t seem to suffer at all. If we increased memory to 8GB, it’s possible you might even see some gain, though it’s hard to say. Note that 32-bit POV-Ray under 64-bit Windows seems to take a substantial hit, but the beta 64-bit version takes care of that.

Perhaps most encouraging is the gain demonstrated by Cinebench. As we see more 64-bit applications emerge, memory hungry apps should indeed benefit from the larger address space. Continued…

3DMark05 is a forward-looking graphics benchmark, but it does offer a CPU test that runs vertex shaders in software, making the CPU do some of the work normally left to the GPU.

Surprisingly, the score for the second 3D Mark 2005 CPU test seems to pick up a bit when running in Windows x64. It’s only a small gain, but repeatable on our test system.

We see some performance hits in a few games, most noticeably Flight Simulator 2004. But all the differences are really minor, and won’t likely be noticed by people actually playing the games. Continued…

Crytek released a pair of 64-bit patches for Far Cry, a highly detailed and graphically rich first-person shooter. The first patch just adds 64-bit support, while the second adds enhancements to the game itself, such as more-detailed and destructible environments. We tested the 32-bit version on both operating systems, plus the 64-bit “bare” and “enhanced” versions.

The good news is that 32-bit Far Cry (as of the 1.31 patch) runs fine under Windows 64-bit mode, with very little performance penalty. When we move to the base 64-bit version, we pick up a couple of frames per second at 1280×1024, but we defy anyone to actually notice the difference between 79.5 and 82 fps.

The good news is that the enhanced version still clocks in at 80 fps. This bodes well for 64-bit gaming, as game developers can add substantial new content and detail without sacrificing performance. Continued…

Running Windows 64-bit isn’t necessarily a binary decision (no pun intended). You can, if you’re willing to have multiple physical disk drives, have a dual-boot system. The key issue is driver support, which is still spotty. For example, Ubisoft and other European game publishers often use Starforce, a device-driver-based content-protection scheme. Starforce has shipped drivers for 64-bit Windows, but two Ubisoft titles—Splinter Cell: Chaos Theory and Silent Hunter III—haven’t been updated to work with 64-bit Windows.

Driver issues aside, Windows XP Professional x64 Edition seems to be stable and solid operating system, and we can cautiously recommend it if you’re willing to live in a dual-boot environment and are willing to manage your expectations when it comes to driver support. We’re really encouraged by the minimal performance losses and encouraged by the potential gains of 64-bit applications.

Microsoft seems to be putting most of its 64-bit desktop development muscle into Windows Vista, so if you’re really hankering for a 64-bit version of Windows, you may want to wait until Vista launches. Also, 64-bit applications don’t seem to be shipping in droves, so it’s likely that you’ll want to wait, unless you’re a developer.

Product: Windows XP Professional x64 Edition
Company: Microsoft Corp.
Price: $140 check prices
Pros: Full support for 64-bit processors; 64-bit application support (if you can find them); good performance with 32-bit apps.
Cons: No 16-bit application support; spotty driver support; dearth of 64-bit apps.
Summary: It’s more of a curiousity than a useful OS for the majority of desktop users, since most Windows 64-bit development seems to be targeted towards Windows Vista.

Related articles: