gpu mem does not add performance ...

margag_

Distinguished
Oct 24, 2005
451
0
18,790
OK the more sys mem you got the more powerful is your'e system we all know that.... then why does adding gpu mem does nothing to gpu performance.... with agp there was the infamous bottleneck...
then pcie was supposed to be the bandwith heaven....but it is not.

Can somebody shed some light on this i'm begining to think :twisted: voodoo magic :twisted: is involved here .....(not the 3dfx) standard vodoo magic with little chickens and everything...(but not the movie).......ok :?:
 

Crashman

Polypheme
Former Staff
First of all, your first guess was wrong. Systems only use a certain amount of system RAM, anything more than what's being used actually slows the system down! That's why so many people are choosing 1GB of system RAM over 2GB, and 2GB over 4GB.

The same is true of video cards, not that many games are using in excess of 256MB. Most don't use in excess of 128MB.

What's worse, many cards have used slower RAM on 256MB versions than on 128MB versions, so they could keep the pricing reasonable.
 

coolsquirtle

Distinguished
Jan 4, 2003
2,717
0
20,780
OK the more sys mem you got the more powerful is your'e system we all know that.... then why does adding gpu mem does nothing to gpu performance.... with agp there was the infamous bottleneck...
then pcie was supposed to be the bandwith heaven....but it is not.

Can somebody shed some light on this i'm begining to think :twisted: voodoo magic :twisted: is involved here .....(not the 3dfx) standard vodoo magic with little chickens and everything...(but not the movie).......ok :?:

Windows 32bit edition stops speeding up after 2gbs of ram, its really pointless to add more.

And for GPU memories, bandwidth and memory speed has greater impact on performance than size
 

margag_

Distinguished
Oct 24, 2005
451
0
18,790
Ok i did not had more than a gig of ram ever..lucky for me...had the sweet spot without knowing it :lol:

i know the ddr 1 2 3 thing but why do they put 256 mb on a card ?
Are the mfg fishing (if so call me fish) or is it a mine is bigger than your's thing?

Is a ddr1 256mb card some how futureproof?
Should i have bought a dd2 128mb card ?

(i bought a budget msi nx6600le ddr1 256mb o/c it to 375/533 and riva tuned it 8x1.3vp paid 135$ canadian)
 
Did I mention I was able to unlock the extra 64mb on my laptop's X700?

I found that for D3 and FartCry that had more of an impact than anywhere else. Of course moving the clocks from 350/330 to 400/400 also helped, but that was a separate boost.
 
Here I'll show you the two seperate ones (3Dmk03 for 64mb and 3Dmk05 for 128mb [same rig]).

http://service.futuremark.com/compare?2k3=4280452
http://service.futuremark.com/compare?3dm05=1292166


It's always been 128MB, they just disable 64MB for some reason in the Canadian version (look at their US website);

http://www.gateway.com/products/gconfig/prodhmseries.asp?seg=hm&gcseries=gtwynx850&clv=Img

When using the standard Gateway drivers it displays 64MB when using the ATi unmoded drivers it reports 128MB. Nice little bonus. 8)

BTW, the 3Dmk03 400/400-128MB result is 6362, which is well above my desktop result, as you well know.
 

margag_

Distinguished
Oct 24, 2005
451
0
18,790
Ok was dumb 8O but aren't all questions worthy like they say in primary school :tongue: ... i will keep on learning then :idea:
did not know the limits but i was not completely wrong....was i?

Strike one for margag_ i have two left ... :wink:
 

cleeve

Illustrious
From what I understand, the reason more memory doesn't do much is because games are designed to use only so much...

Video memory is primarily for textures, so more memory = the *ability* to use higher quality textures.

However, if the game developers target 128-mb videocards, they might not include a 256-mb texture set. In this case, it doesn't matter if your card has 128 or 256mb...

In newer games like Doom3, a 512mb ultra-high texture set is included, and if you use a 256mb card on that setting, it has to swap texture memory from somewhere else (system RAM or even the hard disk), which slows things down tremendously.
 

margag_

Distinguished
Oct 24, 2005
451
0
18,790
oki.. could it be ...

is that why there is a setting called 'agp texture mem' in riva tuner where you can set the amount of sys ram to allocate in agp mode (they say)? could that be a 'limitation' setting ?

think i'm beginning to understand something here :idea: ....
 

cleeve

Illustrious
I've never heard of that before, but I'll wager it's just another name for the "AGP Aperture" setting found on most motherboards, which is measured in megabytes of RAM...

AGP aperture has little to no bearing on performance. It is a nebulous, misunderstood setting that in *no way* reserves system ram for your videocard or games.

Do a search on AGP aperture to get more info, but suffice it to say it will have no impact on performance. Try different settings with 3dmark to test it out for yourself.
 

margag_

Distinguished
Oct 24, 2005
451
0
18,790
it look's like it is reserving (or limiting) sys mem for texture storage
accesible in what they call 'agp mode?'

in everest home edition i can see my diff settings in the gpu section.
tried 128mb 256mb but performance wise it did not change a thing.

maybe it's just adressing mem that w'ont be use at all....

i'm still curious about that mem reservation thing....
 

knownalien

Distinguished
Jan 23, 2003
371
0
18,780
what no one here said was WHY more RAM makes Windows XP (32) run faster. It's a different reason that directly impacts how it cannot be compared directly to Video onboard RAM.
 

cleeve

Illustrious
Why does WinXP run better with more RAM? It's kind of similar to video RAM, in that after a certain point, more RAM is useless.

Windows needs a bunch of RAM to run. I've seen relatively bare XP installations using 128+ megs at idle.

A machine with only 128mb of RAM is going to be swapping files to and from the hard disk constantly, and will slow to a crawl... it might even hit the RAM limit while booting up, in which case simply getting to the desktop will take seemingly forever.

So a 256mb machine should be able to run without a swap file, right?

Sure, everything is fine and quick, unless you run programs that use up more RAM than is left over by windows...

...and once again, you're back using the swap file and slowing to a crawl.

So, oprating system of video, everything slows down once the required info can't be stored in RAM, and the computer has to use a swap file.
 

cleeve

Illustrious
it look's like it is reserving (or limiting) sys mem for texture storage accesible in what they call 'agp mode?'

Not really... well, "limiting" maybe, but not reserving...

First off, "AGP mode" is used every waking second an AGP videocard is in your computer.

Secondly, do you know what the "aperture" of a camera is? It's that little hole that lets light in. If you open the aperture wider, you let more light in.

If I set an aperture to allow twice the amount of light in, the aperture itself is not holding that light; it's just letting more through.

From it's name, I presume that "AGP aperture" may indicate the amount of data that is thoroughput to the videocard in a packet, or something of that sort.

But it's not actually reserving an amount of your system RAM for video.
 

knownalien

Distinguished
Jan 23, 2003
371
0
18,780
which brings me to my next issue. System Ram and the OS have access to the Hard Drive via the swap file. In my case I just turnedf it off. But the stuff loaded into the RAM onboard a video card does NOT have access to the pagefile, right?
 

Snorkius

Splendid
Sep 16, 2003
3,659
0
22,780
The benchmarks here are a very good at illustarting the whole 128/256 question. (compare the N6600GT Silencer with 256mb with the regular old 128mb 6600GT) In some games like Painkiller and BF2 on high settings the difference is marked.
 

cleeve

Illustrious
But the stuff loaded into the RAM onboard a video card does NOT have access to the pagefile, right?

Software (in this case, a game) would make it's own pagefile as it needs to.

I don't think it would be using the Windows page file, but I am not a hardcore programmer... so if there is someone out there who has direct knowledge of these things, feel free to correct...
 

knownalien

Distinguished
Jan 23, 2003
371
0
18,780
i was under the impression that all software used the pagefile too. for example, right now I am running 358 megs out of 1894megs (no pagefile). when I load Morrowind I am using 457. So the game is reading of of the HD for the textures and sounds and what not, but it is clearly loading something into the pagefile. The grey area here is what gets loaded into the video card's ram. the why and how.

oh, and keep in mind that I don't have a pagefile, so what I am talking about is my physical RAM.