longstreet
join:2004-11-14
Plano, TX
3 edits | reply to elios
Re: Windows Vista and RAm
Elios,
This just isn't correct. It's bad information. You know a few things, but either i'm not making it clear or you just don't understand how it works.
The important factor is addressing.
Video RAM is addressed... period. That reduces the amount available to the system ... period.
Installing a 1 gig card on a 32 bit OS REDUCES addressable space by 1 gig . . .period.
That's not good when you have someone needing more main memory.
Considering that there's only 3 gig left addressable, the other system devices will take some of it, leaving the OP with less than 3 gigs of memory free and clear.
It doesn't SHOW this in system information like i'm talking about.
If my suggestion is taken, then a FULL 3 gig will be available solely as main memory.
If she upgrades to a 1 gig card and bumps the memory, less than 3 gig will be available... |
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elios
join:2005-11-15
Springfield, MO
 ·Mediacom
| said by longstreet  :Elios, This just isn't correct. It's bad information. You know a few things, but either i'm not making it clear or you just don't understand how it works. The important factor is addressing. Video RAM is addressed... period. That reduces the amount available to the system ... period. Installing a 1 gig card on a 32 bit OS REDUCES addressable space by 1 gig . . .period. That's not good when you have someone needing more main memory. yes but the GPU the drive then make a maps out a range that OS and CPU use to move data in pages just like swap file does
think of local ram on the GPU as swap space the CPU doesnt need to know the address of all of it just a range
the CPU then uses this range to page data in and out
if this was true then the page file would ALSO have to be addressed also limiting the usable system ram its not
and the GPU is treated in the same way as the swap file
like dave said the physical address are much smaller then virtual ones used to map out vram |
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longstreet
join:2004-11-14
Plano, TX | Anytime we start using a drive for memory, we've just lost the whole point of the conversation. |
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elios
join:2005-11-15
Springfield, MO
·Mediacom
2 edits | said by longstreet :Anytime we start using a drive for memory, we've just lost the whole point of the conversation. not really the ram on the card is treated the same there is physical address range that maps to a vitrual one /thread
the card could have 1MB or 10GB doesnt matter
what changes is the size of that range which maxes out at ~512MB give or take
the GPU has its own memory controller and addressing
this then gets mapped to a physical range ~512MB wide regardless of Vram size
ie
a GTS260 with 800+MB on it in a 32bit XP set with 4GB of ram i see ~3.25 or so useable
512MB of that is GPU addressing the rest is other stuff that needs memory ranges |
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longstreet
join:2004-11-14
Plano, TX
3 edits | CPU to Memory operations are several order of magnitude faster than CPU to drive operations.
Anyway, I think this tangent has gone on long enough. There's not much knowledge the OP probably has gained through this.
Basically, with my suggestion the system would not start CPU -> drive operations as soon. That's my point in a nutshell.
If the problem were the size of the video card and not the system memory, THEN you may have a point. |
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elios
join:2005-11-15
Springfield, MO
·Mediacom
2 edits | wow your slow
it was just to show how it works >.>
the GPU pages ram just like swap file same IDEA
just like how the swap file doesnt need to have physical address for whole thing
the GPU does not need ALL of the ram mapped just a window it can use to page and for other IO
if you look at your GPU in device manager you will see it has 3-4 ranges 2-3 are for bulk data and 1 is for command IO
the GPUs ram is mapped virtually in the driver then paged via a hole the driver makes in the physical address space
BOTTOM LINE RAM ON THE GPU DOES NOT IMPACT USABLE SYSTEM RAM ANY MORE THEN ANY OTHER GPU BE IT 256MB or 10GB JUST LIKE THE SIZE OF THE SWAP FILE DOES NOT HAVE AN IMPACT ON USABLE RAM |
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longstreet
join:2004-11-14
Plano, TX | I'm talking about addressing space. Video memory size reduces addressing space. No room for debate on that.
Sometimes it can take more, up to a gig, but it's never less than the amount of memory on the card. |
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elios
join:2005-11-15
Springfield, MO
·Mediacom
3 edits | i can prove that wrong right now
note the ranges for the GTX260 add up to much less then is on the card
/thread have a nice day
the bigest range D0000000 to DFFFFFFF is 256MB in size all the others are 16 to 32MB total usage less then 512MB
total local ram on the card 896MB |
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HeavyHemi
join:2001-05-24
98500
2 edits | reply to longstreet
LOL, you just have to love these guys obviously used to running notepad on a low end system. |
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Margolis
Premium
join:2003-11-24
Saint Louis, MO
·Charter Pipeline
| reply to Duchess44
WoW is very cpu and memory intensive. More memory helps. A 64 bit os helps in that aspect since it is able to use the extra memory more efficiently.
Here is a shot of mine tonight in 10 man naxx. 64bit vista.
I was at 1.16GB memory before starting the game. |
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HeavyHemi
join:2001-05-24
98500
1 edit | reply to longstreet
Actually 2 sticks of 2Gb would be a far better choice and cost essentially the same. That isn't really debatable. But it is entertaing to read someone give bad advice and incorrect information with the absolute certainty of the truly clueless. |
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Margolis
Premium
join:2003-11-24
Saint Louis, MO
·Charter Pipeline
| reply to Duchess44
I don't know who is being called clueless here, but Longstreet is correct. vista/xp 32 are limited to 4GB address space. That includes space for bios, pci bus, video memory, etc... With a 1GB video card, only ~3GB of system memory will be usable. |
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elios
join:2005-11-15
Springfield, MO
·Mediacom
4 edits | said by Margolis :I don't know who is being called clueless here, but Longstreet is correct. vista/xp 32 are limited to 4GB address space. That includes space for bios, pci bus, video memory, etc... With a 1GB video card, only ~3GB of system memory will be usable. FUUUUUUUUUUUUUUUUU
did you MISS ALL MY POST IT DOESNT WORK THAT WAY
THE RAM ON THE CARD IS NOT MAPPED 1 TO 1 ANY MORE AND HASNT BEEN SINCE MOST CARDS HAD OVER 256MB ON THEM
RAGGGEEEE
ITS THE SAME IN THAT SWAP FILE IS NOT MAPPED 1 TO 1
WHY IS THIS SO HARD TO UNDERSTAND JUST LOOK AT THE LAST POST I MADE
»en.wikipedia.org/wiki/Virtual_address_space
Dynamic address translation
If, while executing an instruction, a CPU fetches an instruction located at a particular virtual address, fetches data from a specific virtual address or stores data to a particular virtual address, the virtual address must be translated to the corresponding physical address. This is done by a hardware component, sometimes called a memory management unit, which looks up the real address (from the page table) corresponding to a virtual address and passes the real address to the parts of the CPU which execute instructions. If the page tables indicate that the virtual memory page is not currently in real memory, the hardware raises a page fault exception (special internal signal) which invokes the paging supervisor component of the operating system (see below).
vram is paged JUST like the swap file it has memory range it uses for this usely no bigger then 256MB or so |
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dave
Premium,MVM
join:2000-05-04
not in ohio
 ·Verizon Online DSL
 ·Verizon FIOS
| What you wrote about the MMU (Dynamic Address Translation) is true but irrelevant, since it describes how the virtual address space seen by code executing on the x68 is mapped to physical addresses. And mentioning the need to read in pages from disks will confuse everyone.
Back to your main point.
It is entirely possible that a graphics board can possess more memory than it exposes to the physical address bus (PCI, AGP, or the modern replacements) on the system. There's no law of nature that requires everything in the computer to see all memory that the graphics board possesses. The only memory that needs to be bus-addressed is memory that is used for communication between the CPU(s) and the graphics processor(s). And it's also possible for a large amount of physical graphics-board memory to be selectively paged(*) into and out of a much smaller window of bus address space.
(*) does not imply anything gets copied, which would be slow. This is simply a change in some bus-to-board mapping hardware.
So, you're describing a plausible scenario. I don't know enough about current board architecture to know whether that's what actually happens. I tend to suspect you're right, since from the viewpoint of the entire system, having an N-gigabyte device claim N gigabytes of scarce(**) bus address space _all the time_ would be a terrible design.
(**) scarce from the point of view of a 32-bit physical address width limit. Likely ok for 36-bit, fine for the 48-bit-or-whatever limit in current 64-bit systems, but these board designers know they're selling today into the canonical 32-bit Windows desktop. |
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elios
join:2005-11-15
Springfield, MO
·Mediacom
| the data does infact get paged this is why we have huge amounts of ram on cards
copy to and from system ram is VERY SLOW even over PCI-e
when you load a level for game it loads all the assets for that level that will need to in the vram space a head of time
console with shared system/vram steam the data as needed which is why they get away with much smaller ram sizes
but on the PC front everything is loaded a head of time
and data is paged in an out as needed
if you have ever tryed to play a game on an older GPU with less then 256MB ram with lots of AA and high res textures you get stuttering this is a symptom of the copying that has to be done when the card runs out of local ram and has to swap to system ram for more textures |
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dave
Premium,MVM
join:2000-05-04
not in ohio
·Verizon Online DSL
·Verizon FIOS
| reply to Margolis
Here: »www.nvidia.com/object/product_qu···_us.html
is a 4GB graphics card. It is supported on 32-bit Windows XP and 32-bit Windows Vista.
Do you suppose that a 4GB graphics card consumes 4GB of physical address space out of the total of 4GB of physical address space available to the entire system.
I don't know the answer, but my guess is "no, it doesn't" 
So, in principle the idea that an N-GB card always uses N GB of address space is not true, no?
(Of course, particular cases may use up the whole N, I'm not saying they never do). |
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ztmike
Mark for moderation
Premium
join:2001-08-02
Michigan City, IN | reply to Duchess44
lol..wow this thread got derailed like a train wreck.
What did the OP ever go with? |
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Duchess44
Premium
join:2001-10-24
Chattanooga, TN
·Comcast
| Nothing yet. I am so confused at this point I really don't know what to do. I don't understand most of what has been said here, and I would love if someone could please tell me in layman's terms what I should get. I am tempted to go with the 3gigs of RAM, however. |
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dadkins
Can you do Blu?
Premium,MVM
join:2003-09-26
Hercules, CA
·Comcast
| said by Duchess44 :Nothing yet. I am so confused at this point I really don't know what to do. I don't understand most of what has been said here, and I would love if someone could please tell me in layman's terms what I should get. I am tempted to go with the 3gigs of RAM, however. Just go with the 3GB and disregard all the posturing being thrown around in this now dead thread. 
--
Think outside the Fox... Opera |
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ztmike
Mark for moderation
Premium
join:2001-08-02
Michigan City, IN
·Comcast
| reply to Duchess44
said by Duchess44 :Nothing yet. I am so confused at this point I really don't know what to do. I don't understand most of what has been said here, and I would love if someone could please tell me in layman's terms what I should get. I am tempted to go with the 3gigs of RAM, however. From a gamer to a gamer..honestly man..the savings you would get for going with 3gigs instead of 4 is not that much..
If I was you, I would just go with 4gigs. What type of ram do you have? I'll see what I can find for prices. |
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