AGP Aperture size and onboard RAM

Bullitt

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I had a quick question about aperture size and RAM. I've tried to read up on as much info I could find, but any reviews about modifying AGP aperture size that I have found were done on 2+ year old hardware and games.

Am I understanding correctly that the aperture size _reserves_ system ram for AGP texture use? ie. If I have a 128MB card and an aperture size of 256MB with 1GB of system memory, I would only have 768MB of available system ram for applications and up to 384MB of texture memory?

If it doesnt reserve it, does it mark it as "available" for use?

I suppose my question is this:
With modern games, Ultra-supa-mind-boggling settings, a 256MB card can get used up. Also with some games, they use a ton of memory, but even with 1GB of ram, that can get stretched thin if game-memory + system + agp aperture memory gets eaten?

Soo, would an extra 512MB coupled with an increased AGP aperture size positively impact game-play at super-duper settings?



The reason I ask is I just got my gf6800gt and was playing EQ2 on "Ultra" settings. It was absolutely fine until I got some new models on the page and I noticed my HDD was lit up. I am used to the game taking up just over 512MB of ram at "balanced" and wondered if it was swapping out ram to virtual memory b/c my AGP was hogging the free ram due to my 256mb aperture size.


Ok, if I'm talking out of my ass, I apologize. I'm hopped up on a liter of coffee as I try and stay awake on this 12-hour night-shift.
 

Dunamis

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Look at it as somekind of swapfile for your vidcard, if they need more mem then they'll use your system RAM with the ceiling value of your AGP aperture setting, so it will use the amount that it needs.

And, no 64 is not the *best* value, it depends on your vidcard and game requirements (amount of texture req, etc), the more it has the less it needs external mem, for example the Nalu demo from NVidia wont work properly on GF6800nu unless aperture is set 128 or greater.

Check this out

And a little more searching wont hurt either, this thing has been asked numerous times.
 

Bullitt

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Forgive the lack of a search....
My question revolves less around "what does the AGP aperture setting do" or "What should my aperture size be set to"

Let me re-phrase a tad:

If I have a game I know will be using 512MB of texture memory, I have a game that requires 700MB of ram, and an OS that uses 100MB, and a vid-card that has 256MB.

I now lack the physical memory to swap out the textures to ram, right? I _want_ my aperture size to be 256MB to make my available texture memory to be 512, but I dont have enough system ram to do the swapping, right?

Will more memory reduce the paging to HDD or is that an effect of something else?
 

robberbaron

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Bullitt said:
Forgive the lack of a search....
My question revolves less around "what does the AGP aperture setting do" or "What should my aperture size be set to"

Let me re-phrase a tad:

If I have a game I know will be using 512MB of texture memory, I have a game that requires 700MB of ram, and an OS that uses 100MB, and a vid-card that has 256MB.

I now lack the physical memory to swap out the textures to ram, right? I _want_ my aperture size to be 256MB to make my available texture memory to be 512, but I dont have enough system ram to do the swapping, right?

Will more memory reduce the paging to HDD or is that an effect of something else?

If you add system ram, less will be paged to the HDD, yes. I think adding system ram would be a good idea.
 

Dunamis

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I'd guess ur talking about Doom 3 at it's ultra setting?

I'm not sure what happens if the vidcard and game starting to compete for ram resource, in case of vidcard wins then I'd guess the game will start to swap in/out its data from page file without affecting vidcard performance itself.
 

Sc4freak

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Dec 23, 2004
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The Video Card will only use the AGP Aperture if it is needed. So it won't "reserve" a portion of your RAM just to itself, not allowing anyhing else to use it. But, for instance, you play Doom 3 in Ultra @ 2048x1536 4xaa 16xaf and your Video Card needs more RAM, then it'll write to system memory with your AGP Aperture the maximum amount of RAM you Video Card will take up. If there is not enough then HDD swapping will occur.
 

Bullitt

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actaully, EQ2. Framerates are good on Ultra, I just think I am out of texture memory. With the game, OS and perhaps a firefox browser open in the BG, it tends to access the HDD when new models get loaded.

Unless anyone knows a util that can show video-memory usage
 

OPUS1

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Apr 25, 2003
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Agp size reserves the system memory block for use when it needs it. It doesn't mean that no one else can have it. My card has 256 mem and 1 gig sys mem. I tried different setups and 64 Agp works fine. What this does is force the Vcard mem to be used first, then it will seek system memory, then swap mem. What I find interesting is that as you said you did a search, as have I, and no two articles are alike. The only common thread is "I'm not sure but..."
Try different setups and see what fits best.
 
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