Personal computing discussed
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M3ZCL4N wrote:Nope, only that XP uses significanly less virtual address space, cause unknown but speculated it has (at least partially) to do with virtualization of video ram in Vista.I don't have the greatest tech level, so while I'm still trying to make sense of the first link, am I correct in my understanding that the follow-up suggests that Vista uses VRAM more efficiently?
Someone on some other forum wrote:There is a fixed amount of intelligence on the planet, and the population keeps growing.
M3ZCL4N wrote:I don't have the greatest tech level, so while I'm still trying to make sense of the first link, am I correct in my understanding that the follow-up suggests that Vista uses VRAM more efficiently?
Virtual memory is also required by DX10, meaning that the GPU can now page data out to system memory if it runs out of memory on the graphics card
Nitrodist wrote:Going to 64bit doesn't double it. If you went from 32bit to 33bit, that'd double it.
Shinare wrote:I have Vista because its asinine to have a DX10 card and not have DX10.
snowdog wrote:I have read both articles. Basically if you Vista, go Vista 64, because Vista 32 has a problem where it eats your address space, nothing to do with installed memory this is the 2GB user address range. You will hit the same problem with 512mb or 4 G of memory installed. The problem is that Vista is mapping video memory into user space. The bigger your Video ram, the more address space you lose in Vista.
murfn wrote:A game is unlikely to allocate more than 2GB of virtual address space if you have only 512MB physical memory. It would mean that you have almost 1.5GB swapped out to disk. Your biggest problem here is performance, as the computer struggles to swap memory pages in and out of disk storage. A game that manages to do this without degrading performance is probably suffering from a serious memory leak. If the system requirement for your game is 2GB, you would do well to invest in 2GB of physical memory. If you have 2GB, an 8800 GFX and a game that requires 2GB and it crashes, the Large_Address_Aware solution and 64bits should be considered.
murfn wrote:A 32bit process has 4GB of virtual address space. Of those, only the bottom 2GB are available for allocation (assuming no Large_Address_Aware). The system uses the top 2GB. The bulk of the virtual address space held by the video card would be in the top 2GB. If I understand it correctly, with the 8800GTS the top 2GB is not enough for the system, and hence a portion of the bottom 2GB is usurped by the system. A machine with 2GB of physical memory, running a game requiring 2GB of memory, would not be able to map the whole 2GB into the less than 2GB of available virtual address space.
Forge wrote:
In the mean time, XP64 is still the best option for the >2GB crowd.
snowdog wrote:Uh no. The top half is kernel space, there would be seriously no point mapping the VRam into kernal space.
snowdog wrote:The problem is VISTA is remapping the whole of the VRAM into the user space. XP doesnt do this, There is no need to do this, it is just done for DRM.
snowdog wrote:Note the size difference between Vista and XP memory usage. 800MB almost identical to the size of the VRAM on the video card.
snowdog wrote:And again. Physical memory is irrelevant to this problem and again the game is taking up 1.3GB on XP, 2+GB on Vista. Has this escaped your notice.
user_virtual_address space = min(2GB,4GB - system_reserved_address_space)
if (physical_memory > user_virtual_address_space)
max_usable_physical_memory = user_virtual_address_space
else
max_usable_physical_memory = physical_memory
Why do you keep trying to defend Vista when it is chewing up all the address space?
murfn wrote:Why do you keep trying to defend Vista when it is chewing up all the address space?
I am explaining the issues to this forum. That is all.
murfn wrote:Take a look at the tables on the first page of AnandTech's article at http://www.anandtech.com/showdoc.aspx?i=3044. The virtual address space at game start is consistently well below your VRAM size. Vista uses the GFX card in a different way to XP. The Aero interface is 3D, which means that the only limit on video memory used by the API is the whole VRAM. To ensure stability, Vista requires the ability to swap out video memory. To do this the video memory has to be mapped to virtual address space. And there is no reason why that cannot be above the 2GB mark.
snowdog wrote:The problem is VISTA is remapping the whole of the VRAM into the user space. XP doesnt do this, There is no need to do this, it is just done for DRM.Where did you get this little gem from?
snowdog wrote:Note the size difference between Vista and XP memory usage. 800MB almost identical to the size of the VRAM on the video card.I am not sure what your original numbers represent exactly.
Code: Select alluser_virtual_address space = min(2GB,4GB - system_reserved_address_space)
if (physical_memory > user_virtual_address_space)
max_usable_physical_memory = user_virtual_address_space
else
max_usable_physical_memory = physical_memory
Why do you keep trying to defend Vista when it is chewing up all the address space?I am explaining the issues to this forum. That is all.
Forge wrote:murfn wrote:Why do you keep trying to defend Vista when it is chewing up all the address space?
I am explaining the issues to this forum. That is all.
I can only speak to my own understanding, but you made everything as clear as mud.
The core issue here is that Vista is chewing up all of the 2GB of system address space and continuing in on the user address space in many, possibly most configurations. This is a critically bad thing. Why it is doing it is tangential, the point that is being made, and that is so very upsetting, is that Vista is breaking something fundamental that worked in every other OS, and nobody has promoted a good explanation as to why.
Forge wrote:The core issue here is that Vista is chewing up all of the 2GB of system address space and continuing in on the user address space in many, possibly most configurations. This is a critically bad thing. Why it is doing it is tangential, the point that is being made, and that is so very upsetting, is that Vista is breaking something fundamental that worked in every other OS, and nobody has promoted a good explanation as to why.
snowdog wrote:This is talking about the new video driver. Vram access is now in user address space primarily for "Security" reasons. That is to keep one application from peeking at the protected video streams, AKA DRM.