Sign in with
Sign up | Sign in

Gaming In 64-Bit: Tom's Tests, Microsoft Weighs In

Gaming In 64-Bit: Tom's Tests, Microsoft Weighs In
By

Five and a half years ago, AMD launched its Athlon 64 processor lineup, extolling the benefits of 64-bit computing and what it’d mean for the future. It didn’t take Intel long to follow suit on the desktop. From there, the infrastructure—the operating systems and drivers—began falling into place to support more 64-bit software.

Today, 64-bit compatibility is almost a given. In fact, in the business space, where 64-bit computing has always been seen to have the most promise, applications have emerged that will only run in 64-bit. Even Small Business Server 2008, a relatively entry-level operating environment for businesses with up to 75 users, is now 64-bit-only due to its inclusion of Exchange Server 2007.

Why did Microsoft make the executive decision to launch its latest messaging platform exclusively in 64-bit trim? According to a blog post by Chris Mitchell in Microsoft’s Exchange Performance Engineering Team, the application uses 64-bit addressing to get its virtual hands on more system memory, preventing repeated trips back and forth to disk. In Chris’ example, an older version of Exchange might have access to 900 MB of a 32-bit server’s 4 GB ceiling. In a 4,000-user enterprise, that's 225 KB of RAM per user—not nearly enough for all of the messages, rules, calendar entries, and contacts in a typical mailbox. Moving to 64-bit and upgrading servers to 10s of gigabytes (Chris’ recommendation in that same 4,000-user business is 24 GB) softens the load on storage.

But desktops aren’t nearly as hard-up for memory, right? We expected 64-bit computing to trickle down from the enterprise, but gamers want to know: where is the benefit from this technology today?

Going To 64-Bit: Because You Can…

Enthusiasts running Socket AM2/AM2+ platforms commonly go with 2 GB or 4 GB memory kits. After all, even though DDR2 memory is cheap, 4 GB is still the enthusiast norm—8 GB is closer to workstation-class.

But when you buy a Core i7-based machine and step up to a triple-channel arrangement, it just doesn’t make sense to slide back the other direction and populate with three 1 GB modules. And so now you’re looking at 6 GB and a forced move to 64-bit computing if you want to actually use all of that memory.

…Or Because You Have To

Oh that’s right—I almost forgot. In case you've been living under a rock since AMD started preaching its 64-bit message, the fundamental limit on how much RAM a 32-bit operating system can see is 4 GB (2^32). Anything more simply won’t show up as installed memory.

Once you factor in device addressing, the magic number actually drops below 4 GB. That’s why it’s common for 32-bit systems with 4 GB to report 3 GB plus change in the Windows Device Manager. It’s not a Windows problem, though. Rather, that’s just how x86 architecture works.

Update:A bit of clarification on the above point--the issue of not seeing a full 4 GB of memory in Microsoft's consumer operating systems is shared between hardware and software vendors. The inability of a 32-bit Windows OS like XP or Vista to use the full 4 GB stems from compatibility issues with older chipsets, as indicated in this paper from HP, preventing devices from being mapped high. Thanks to reader nater for his feedback response on the matter.

Workarounds for reclaiming that lost memory have been introduced, of course. Intel’s Physical Address Extensions enabled 36-bit physical address tables, which did help in server environments by upping maximum memory size to 64 GB. However, according to a presentation given by Chuck Walbourn, senior software design engineer in Microsoft’s XNA Developer Connection at Gamefest 2008, PAE never really worked the way it should in with desktop operating systems, which would have needed to map the 4 GB virtual address space into the greater physical space. Drivers were the main problem, he said. They had application compatibility problems, assuming they always had 32-bits with which to work, not 36.

In addition to the 32-bit physical address lines, you’re also limited to 32-bits of virtual address space. Because one bit is reserved for shared kernel memory (used by all processes and the operating system), individual applications only have access to a maximum of 2 GB of private address space. Suddenly, you’re facing limitations that just might have a more profound impact on a desktop machine. Could taking the 64-bit plunge today actually make a significant difference in your gaming experience? That’s what we’ve set out to explore.

Ask a Category Expert

Create a new thread in the Reviews comments forum about this subject

Example: Notebook, Android, SSD hard drive

Display all 146 comments.
This thread is closed for comments
Top Comments
  • 13 Hide
    salsoolo , March 18, 2009 6:42 AM
    i went 64-bit from last year. i hope that game devs go 64-bit. and every programmer too.

    with Windows 7 around the corner, m$ already said that they expect the majority of windows installations will be 64.
  • 11 Hide
    apache_lives , March 18, 2009 8:02 AM
    heh we forget the main concepts here with 64-bit:

    NO ONE uses a system with nothing bar windows a single game installed - they have a few security apps, torrent apps, messenger, keyboard/mouse apps etc - they all sap up resources, so 64 bit gives all apps all the memory they need - for example 8gb is useless to a 32-bit app, but when you got that hungry game ASWELL as a hungry background app etc they both get the full amount of memory!

    Also lessens the "thrashing" effect on HDD's and helps there lifespan etc


    As for why there arnt any benifits for 64 bit games etc - there all still native 32-bit because all those morons still think there 2gb and XP is "sufficent and up to date" - move to 64-bit so we can all benifit!
Other Comments
  • 13 Hide
    salsoolo , March 18, 2009 6:42 AM
    i went 64-bit from last year. i hope that game devs go 64-bit. and every programmer too.

    with Windows 7 around the corner, m$ already said that they expect the majority of windows installations will be 64.
  • 3 Hide
    curnel_D , March 18, 2009 6:46 AM
    "Given the very known nature of these virtual address space limitations, you’d think that game developers would be taking a more hurried approach to making the transition."

    This mainly has to do with resources. Most developers use the same engine they've built or bought for a span of many years. Take bioware, for instance, who used the Auroa engine for 9+ years, knowing that it was limited to single threads and low memory.
    To switch to 64-bit, these developers would have to take the time not just to modify their existing engines, but more likely rewrite the entire engine because of the changes involved. Something that some developers just cant afford.
  • -1 Hide
    curnel_D , March 18, 2009 7:16 AM
    Oh, and deffinately drop GTA. None of the GTA or games that use the GTA engine have ever been any good on PC, and have never been consistant in indicating graphics performance due to their poorly developed and optimized code. It's a waste of time.
  • 8 Hide
    amdfangirl , March 18, 2009 7:19 AM
    I say the benefit of having full access to 8GB of DDR2 is enough to make me switch to 64 bit. Not using a Page File and being able to use native 64 bit programs like those found in CS4, is worth it enough. The advantage of being able to execute native 64 bit instructions is absolutely heavenly powerful speed boost(CS3 vs CS4).
  • 1 Hide
    spearhead , March 18, 2009 7:28 AM
    indeed 64-bit is good and you can see that in games and applications which take advantage from it. it might require a bit more ram but then 64-bit can handle more applications running at the same time and execution of those applications seems to be alot faster that is what i can tell from my experience with 64-bit vista
  • 6 Hide
    nathanlh , March 18, 2009 7:38 AM
    One of the reasons that x64 games might run slower on 3GB of system memory than their x86 counterpart is that x64 code should be somewhat larger due to the 64 bit addressing itself. If the x86 code is already feeling the squeeze on 3GB, the x64 code will be even more so - resulting in more memory swapping to disk. Also, one of the benefits of x64 code is the use of more general purpose registers which the x64 games tested here might not have made use of.
  • 0 Hide
    Anonymous , March 18, 2009 7:44 AM
    Chris - could you check the same thing on AMD platform? AFAIK there are some performance differencies between AMD and Intel @ 64bit
  • 4 Hide
    amdfangirl , March 18, 2009 8:01 AM
    ^ There were some on Linux with the Athlon 64 and Pentium 4. Gap has really closed tho, I'd say.
  • 11 Hide
    apache_lives , March 18, 2009 8:02 AM
    heh we forget the main concepts here with 64-bit:

    NO ONE uses a system with nothing bar windows a single game installed - they have a few security apps, torrent apps, messenger, keyboard/mouse apps etc - they all sap up resources, so 64 bit gives all apps all the memory they need - for example 8gb is useless to a 32-bit app, but when you got that hungry game ASWELL as a hungry background app etc they both get the full amount of memory!

    Also lessens the "thrashing" effect on HDD's and helps there lifespan etc


    As for why there arnt any benifits for 64 bit games etc - there all still native 32-bit because all those morons still think there 2gb and XP is "sufficent and up to date" - move to 64-bit so we can all benifit!
  • 9 Hide
    amdfangirl , March 18, 2009 8:12 AM
    ^ +1

    We should all be 64 bit.

    Those who play hardcore games should have at least a x64 proc.

    So, devs should make 64bit games simply.

    The world will transition in due time.

    We just are at the frontier.
  • 1 Hide
    williehams , March 18, 2009 8:34 AM
    If simply for the allowance of more ram it makes sense, however Vista64 has even more hardware compatibility issues than Vista32. Trying to install a linksys wireless card was a no go, even with guides and bodged drivers the result was poor, I resorted to an USB wireless adapter instead which is pretty lame.
  • 4 Hide
    powerbaselx , March 18, 2009 9:06 AM
    IMO 64bit OS will be trully significant for home/game users when 3 things happen:
    1) Games and applications will demand more than 2GB RAM each (we're still far away from this reality).
    2) Games and applications will be truly multi-tasking, multi-process, competing each other, and requiring plenty of memory each.
    3) Windows and software houses stop having 32bit versions and 64bit will be massified.

    Currently most benchmarks and articles search for a motive to upgrade to 64bit on performance, which is wrong while home applications and games don't demand more than 2GB RAM each. Today it has nothing to do with performance gains, since as benchmarks reveal it brings no relevant advantage.

    Virtualization (like VMWare ESX and Citrix Xen) is a good motive to have lots of installed memory over 4GB but that's an area for enthusiasts, developers, students and enterprises, not for the masses.
    In an absurd analysis, if each game had its own independent OS to be loaded through a virtualization OS then i'm pretty sure 64bit were pretty much developed and maybe today the standard was 32GB RAM on 16-core PCs! :-)

  • 0 Hide
    San Pedro , March 18, 2009 9:38 AM
    I'd like to see you guys keep GTA for the benchmarks. I disagree with an earlier poster, I think all the GTA ports have been great fun on the PC. I do agree with what was said in the article about it being a hassle with Social Club and Windows Live. Running a mod that disables windows live has been reported in user forums to yield a good amount of extra performance.
  • 2 Hide
    RiotSniperX , March 18, 2009 10:25 AM
    Of course 64-bit would yeild more advantages.

    When your playing WoW, your not just playing WoW,atleast it dont.

    Your running ventrilo,xfire, and sometimes itunes for music, and with 6gb you'd be able to do it no problem.
  • 0 Hide
    wuyanxu , March 18, 2009 10:25 AM
    GTA4 is a very good benchmark, especially in testing MODERN machines. by modern machines, i mean quad core, with lots RAM and vRAM. the only reason it's been viewed as unoptimised is because those dual core losers don't understand the future of computing.

    64bit is the minimal anyone building/buying a machine should be looking at, and 4GB/6GB is also the minimal. Microsoft should have stopped making Win Vista 32bit from the beginning. as always, software developers are too slow to catch up.
    for Win7, with netbooks as part of target audience, Microsoft should ONLY have 32bit netbook edition. all other desktop editions should be 64bit without question.

    posted on a quad core, 8GB RAM, Vista 64bit and sitting here waiting for more native 64bit programs
  • 1 Hide
    powerbaselx , March 18, 2009 10:40 AM
    DonalDuck[/nomThis ignorance of "testing" is almost offensive for IT professionals who know what they are talking about.Why don't you try the difference with some native 64-bit apps? Ray-tracing anyone? Video encoding?

    Virtualization as i said in a post here... (did you read? ...)

  • 5 Hide
    RiotSniperX , March 18, 2009 10:42 AM
    DonalDuckWho cares about gaming. I am sort of fed up with this site talking mostly about gaming and overclocking. It did not use to be this way many years ago... Please change the name to "tomsgamesandoc".Great discover... A game (which performance depends mostly on the GPU) doesn't improve when running in a 64Bit os... Wow... Very strange uh? Expecially considering that the code is in 32bit.This ignorance of "testing" is almost offensive for IT professionals who know what they are talking about.Why don't you try the difference with some native 64-bit apps? Ray-tracing anyone? Video encoding?


    Your missing the point, when running a game, like i said, you could be able to do other things, not be limited to the game and fear lag if you say, decide to go on google for a second.
  • 0 Hide
    gfg , March 18, 2009 11:02 AM
    use 4870x2 in CF. Supposedly AMD has better support for 64-bit.
    And using more powerfull GPU eliminates the bottleneck.
  • 0 Hide
    gfg , March 18, 2009 11:05 AM
    use 4870x2 in CF. Supposedly AMD has better support for 64-bit.
    And using more powerfull GPU eliminates the bottleneck, to see the real diferents.
    I am from Argentina sory my inglish.
Display more comments