AGP Apature

[comikehill2002]

does raising this from 64mb to 256mb really help preformance?

 

[LordVampyre]

it may for your rig.. try it out.. I use 128 and find that to be the best for my system.

 

[Glow]

I asked this for a long time I really don't know if it makes a huge difference

 

[I3roknI3ottle]

ive always wondered what my aparature size is supposed to be at. I have a 128MB card and i have it set at 64MB

 

[flagpolekilla]

for some odd reason my Gigabyte 8KNXP board doesnt have that option of changing the apature size

 

[Jonsey]

does raising this from 64mb to 256mb really help preformance?

In certain games it can help, like running D3 in ultra mode.

 

[legcramp]

for some odd reason my Gigabyte 8KNXP board doesnt have that option of changing the apature size

yah it does..I thought my gigabyte didnt either...

go into bios.... press control+f1 or alt+f1 to bring up the hidden menu

O yeah..and btw....my 6800ultra desn't like 256 agp aperture...128 or 512 seems to work best...I leave at 128

 

[rcf1987]

I always set it at half my system memory.

 

[rcolbert]

I always set it at half my system memory.

That's just plain old bad advice. Do some more research and stop spreading the AGP urban myth.

 

[comikehill2002]

well i turned it up to 256 and WOW it did alot, Fired up Battle fields to just check it out and It looks awsome, but i think it might be too much, going to try 128mb today

 

[vage]

*sigh*

AGP Aperature size is how much of your system memory is set aside to help your video card with graphics. The bigger the memory on your video card, the lower the Aperature size should be. The biggest difference you will notice is when you alt + tab out or quit. If your using a lot of system memory to help your video than it will not quit out as fast as if you are only using 64 MBs.

 

[ThomasE66]

*sigh*

AGP Aperature size is how much of your system memory is set aside to help your video card with graphics. The bigger the memory on your video card, the lower the Aperature size should be. The biggest difference you will notice is when you alt + tab out or quit. If your using a lot of system memory to help your video than it will not quit out as fast as if you are only using 64 MBs.

Close, but it's not so much 'set aside' as it is the maximum available amount of system memory that the AGP card can use as additional memory. It isn't set aside in that it doesn't make that amount of memory off limits to the rest of the system.

 

[cell_491]

hmm wow i never knew that...i thought it just meant how much video ram your card had. when i get my new mobo ill be sure to set it as low as possible

 

[ThomasE66]

hmm wow i never knew that...i thought it just meant how much video ram your card had. when i get my new mobo ill be sure to set it as low as possible

Set it to whatever gives you the best performance. It won't hurt having it set high. Like I said, it doesn't affect your available system memory in any way.

 

[cell_491]

yea but if its low wont it force the gpu to use more of its own, faster, better ram ?

 

[ThomasE66]

yea but if its low wont it force the gpu to use more of its own, faster, better ram ?

No. Your GPU will always use it's on-card RAM first. It uses the AGP Aperture for reading and writing directly to and from system RAM.

In fact, if you set it too small some applications may not work correctly, or with reduced performance.

 

[cell_491]

so what would you suggest i have a BFG 6800gt oc and a gig of gskill pc4400

 

[ThomasE66]

so what would you suggest i have a BFG 6800gt oc and a gig of gskill pc4400

Try 128 and see how that goes. Then try 256 even if you want, but there probably won't be much difference.

 

[cell_491]

i usually have it at 256 so ill try 128 and see if i get a few points in 3dmark

 

[ThomasE66]

i usually have it at 256 so ill try 128 and see if i get a few points in 3dmark

You're probably fine at 256, but it never hurts to play around.

 

[cell_491]

so very true

 

[Scali]

There should be a FAQ for this question, it pops up once a week or so.
I know I've already answered it at least once here.
Short story is: the bigger the better, as far as the graphics card is concerned.
Longer story is: the AGP aperture is taken from the system's main memory... this means that if you set it to 256 mb, you could run into situations where the entire aperture is used, which means you will have 256 mb less main memory... With a system that only has 512 mb (or even less), that is not a good thing ofcourse... so you may want to use a smaller aperture in that case. But on a system with 768 mb or more, I'd recommend 256 mb, that should work fine in most cases (well games anyway, if you're into 3d modeling or such, you may have other requirements).

 

[ThomasE66]

There should be a FAQ for this question, it pops up once a week or so.
I know I've already answered it at least once here.
Short story is: the bigger the better, as far as the graphics card is concerned.
Longer story is: the AGP aperture is taken from the system's main memory... this means that if you set it to 256 mb, you could run into situations where the entire aperture is used, which means you will have 256 mb less main memory... With a system that only has 512 mb (or even less), that is not a good thing ofcourse... so you may want to use a smaller aperture in that case. But on a system with 768 mb or more, I'd recommend 256 mb, that should work fine in most cases (well games anyway, if you're into 3d modeling or such, you may have other requirements).

Yes, you can also run into situations where the AGP card tries to use the large aperture but system memory is low. Swapping of stuff in main memory ensues, performance takes a dive into the crapper, dogs and cats sleep together, etc.

Again, there is no one size fits all approach. Not even the 'bigger is better' holds true.

 

[burningrave101]

If you have a gig of RAM i dont see any reason not to set the aperture size to 256MB. I've seen some of the manufacturers for the 6800GT recommend setting it to 256MB to match the available on-board memory. It doesn't use that memory set aside unless it needs it and if it needs it and you dont have enough set aside then its going to have to start swapping out the available memory.

I would say 256MB could be beneficial in games like DOOM 3 when your playing at a high resolution in high detail.

 

[ThomasE66]

If you have a gig of RAM i dont see any reason not to set the aperture size to 256MB. I've seen some of the manufacturers for the 6800GT recommend setting it to 256MB to match the available on-board memory. It doesn't use that memory set aside unless it needs it and if it needs it and you dont have enough set aside then its going to have to start swapping out the available memory.

I would say 256MB could be beneficial in games like DOOM 3 when your playing at a high resolution in high detail.

QFT

I still say people should test to make sure they have the optimal setting, but a good starting point is Aperture = Video Memory.

 

[Scali]

I still say people should test to make sure they have the optimal setting, but a good starting point is Aperture = Video Memory.

It's very hard to test such things... Like with Fast Writes and AGP4x vs AGP8x, there are many situations where there is absolutely no difference, yet there are also situations where you do notice...
In general though, it doesn't hurt to use the faster/bigger settings, if they are not used.

I also think the rule of thumb of AGP setting related to videomemory is silly. The less videomemory you have, the more AGP aperture you want. For the videocard, more is always better, as I said before. The catch is that the main memory decreases...
If I were to give any rule of thumb, I'd suggest something along the lines of "Set your AGP aperture to at most 1/3rd of your main memory".

 

[ThomasE66]

It's very hard to test such things... Like with Fast Writes and AGP4x vs AGP8x, there are many situations where there is absolutely no difference, yet there are also situations where you do notice...
In general though, it doesn't hurt to use the faster/bigger settings, if they are not used.

I also think the rule of thumb of AGP setting related to videomemory is silly. The less videomemory you have, the more AGP aperture you want. For the videocard, more is always better, as I said before. The catch is that the main memory decreases...
If I were to give any rule of thumb, I'd suggest something along the lines of "Set your AGP aperture to at most 1/3rd of your main memory".

It's not at all hard to test the stability and performance by running benchmarks of your favorite games. That is what tweaking is all about. Change a setting, test, lather, rise, repeat.

I also think the fact that you think the rule of thumb is silly is in itself silly. AGP texturing is notoriously slow, and trying to rely on too much system memory to augment your card's abilities invariably leads to very poor performance.

Still, as with all things tweak related, ymmv. Do what works for you.

 

[Scali]

It's not at all hard to test the stability and performance by running benchmarks of your favorite games. That is what tweaking is all about. Change a setting, test, lather, rise, repeat.

I guess you missed the point.
The point was that you can only measure increased performance in cases where the settings are effective... and these cases are relatively rare. Most games will work fine with just 128 mb videomem, especially if you don't set texture detail to maximum, so you can test any aperture size you want, and not measure a difference. But it would be wrong to conclude that the AGP aperture size will not affect performance at all, anywhere.

I also think the fact that you think the rule of thumb is silly is in itself silly. AGP texturing is notoriously slow, and trying to rely on too much system memory to augment your card's abilities invariably leads to very poor performance.

AGP texturing is not all that slow on an AGP8x system... and it sure beats the alternative of swapping textures in and out manually, using the CPU.
Besides, the size of the aperture doesn't control the amount of AGP texturing, the texture settings in the application do. So it's still always better to set the AGP aperture larger, and instead reduce the texture size in the application.
The only problem is when you can't control the size of the textures in the application, and have to depend on whatever the application picks for you.

 

[comikehill2002]

Didnt see a big Dif. between 256 and 128

 

[ThomasE66]

Maximum theoretical AGP 8X bandwidth= 2,133 megabytes/second
Memory speed of a 6800 GT (just for comparison's sake) = 32 gigabytes per second.

AGP texturing is woefully slow, period. It is almost uselessly slow.

Setting the optimal AGP aperture can be as easy as following the recommendations or as involved as actually testing various sizes.

 

[Scali]

Maximum theoretical AGP 8X bandwidth= 2,133 megabytes/second
Memory speed of a 6800 GT (just for comparison's sake) = 32 gigabytes per second.

2133 mb/s is also 2.1 gigabytes per second... I don't see why you would deliberately use different units to compare speeds, unless you want to create the impression that the difference is much larger than it actually is.
So yes, AGP texturing is roughly 16 times as slow as one of the fastest videocards you can find on the market today. Pick a more common card, such as an 9600 (6.4 gb/s), and the difference will suddenly be a lot less dramatic. Heck, only a few years ago, videocards didn't even have 2.1 gb/s videomemory to begin with, yet we used those, didn't we?

That's not the point though, is it? First of all, generally the faster the card, the more memory it will have, so the less dependent it will be on AGP texturing...
Secondly, you shouldn't compare AGP texturing to videomemory, since videomemory will always be used first, regardless of aperture size. The thing you should be comparing is what happens when you run out of videomemory. In this case it is surely better to have a larger AGP aperture than to keep paging textures in and out, or even worse, skip some textures altogether and get untextured surfaces onscreen.
The only pitfall here ofcourse is that you don't want to take up so much systemmemory that the OS will have to start paging out parts of the application and such. This is the balance you should be finding. But as I said before, in most cases you should be able to control that with the texture detail settings in the application.

You're just trying to argue that AGP texturing is slower than videomem, so it should not be used at all? That's nonsense ofcourse. AGP texturing is only used as a fallback when there is not enough videomemory available. So you're arguing the wrong point.
The real point to argue would be that you have insufficient memory on your videocard for the tasks you want it to perform.
But we're discussing how to get the most of the videocard in this situation instead.

 

[ThomasE66]

I thought most people could tell the difference between gigabytes and megabytes, I even bolded GIGA. Ok 2 gigabytes vs 32 gigabytes

Some people just like to argue.

EDIT: Nowhere did I say it shouldn't be used, either. Quote me. I just pointed out that your statement about AGP 8x texturing having good performance was bs.

 

[Scali]

EDIT: Nowhere did I say it shouldn't be used, either. Quote me. I just pointed out that your statement about AGP 8x texturing having good performance was bs.

No, you compared it to something that wasn't relevant. It won't perform as well as videomem obviously, but nobody claimed that. But it will perform better than the alternative option. So my statement wasn't at all bs, you just interpreted it the wrong way.

 

[lesman]

AGP aperture size is more like an address base for memory. If you start to run out of memory on your video card, it will start using up the AGP aperture addresses. HERE'S a very good, straight to the point article on good aperture settings. I strongly advise everyone's reading of this.