Hae-Yu
08-14-2007, 03:30 PM
Anandtech uncovered a flaw in the way Vista handles applications (specifically games) that consume more than their alloted 2GB of address space. MS has released a patch.
There are 3 articles in the series and the reading is interesting in that it points to the inevitable decline of 32-bit architecture - sooner than we think.
32-bit Windows assigns applications a 2GB memory address space which is NOT the same as the amount of physical memory (RAM) installed. Apps will almost always use more address space than memory and this usage is not tracked via the Task Manager. The first article (http://www.anandtech.com/gadgets/showdoc.aspx?i=3034)gets into this. This is the "2GB barrier" you hear when comparing 32-bit and 64-bit Windows. Adding more RAM will not help as this is not about physical memory.
Once an app hits this barrier, it crashes unexpectedly and is difficult to troubleshoot. The normal fix for Vista users is to download the hotfix from Microsoft (links in article 3 (http://www.anandtech.com/systems/showdoc.aspx?i=3060&p=1)) AND a latest video driver. For patched Vista or XP users, the next step, and one we will all encounter with newer, resource intensive games & apps, is to scale back the settings.
Criticially, although this particular excessive use was generated by a bug, it lead to further analysis of resource usage. Games such as Company of Heroes, STALKER, and Supreme Commander are consuming 75% of that limitation under XP. By the end of this year, the next crop of games will routinely hit the 2GB barrier and crash or force users to dial down the snazzy effects. The only way to get around this issue is to upgrade to a 64-bit OS with 64-bit apps, with 8TB of address space
In this particular instance, Vista's excessive usage was a compatibility bug between the new driver model and Direct X 9 apps that has been patched to bring it back on par with XP. Additionally, under Vista, the more video RAM on a GPU, the more resources were consumed, leading to app crashes. Keep in mind Anandtech article 3 (http://www.anandtech.com/systems/showdoc.aspx?i=3060&p=1) shows that there is no performance penalty with an unpatched system - framerates for 3 games were identical pre- and post-patch.
There are 3 articles in the series and the reading is interesting in that it points to the inevitable decline of 32-bit architecture - sooner than we think.
32-bit Windows assigns applications a 2GB memory address space which is NOT the same as the amount of physical memory (RAM) installed. Apps will almost always use more address space than memory and this usage is not tracked via the Task Manager. The first article (http://www.anandtech.com/gadgets/showdoc.aspx?i=3034)gets into this. This is the "2GB barrier" you hear when comparing 32-bit and 64-bit Windows. Adding more RAM will not help as this is not about physical memory.
Once an app hits this barrier, it crashes unexpectedly and is difficult to troubleshoot. The normal fix for Vista users is to download the hotfix from Microsoft (links in article 3 (http://www.anandtech.com/systems/showdoc.aspx?i=3060&p=1)) AND a latest video driver. For patched Vista or XP users, the next step, and one we will all encounter with newer, resource intensive games & apps, is to scale back the settings.
Criticially, although this particular excessive use was generated by a bug, it lead to further analysis of resource usage. Games such as Company of Heroes, STALKER, and Supreme Commander are consuming 75% of that limitation under XP. By the end of this year, the next crop of games will routinely hit the 2GB barrier and crash or force users to dial down the snazzy effects. The only way to get around this issue is to upgrade to a 64-bit OS with 64-bit apps, with 8TB of address space
In this particular instance, Vista's excessive usage was a compatibility bug between the new driver model and Direct X 9 apps that has been patched to bring it back on par with XP. Additionally, under Vista, the more video RAM on a GPU, the more resources were consumed, leading to app crashes. Keep in mind Anandtech article 3 (http://www.anandtech.com/systems/showdoc.aspx?i=3060&p=1) shows that there is no performance penalty with an unpatched system - framerates for 3 games were identical pre- and post-patch.