Which cards actually need 8x AGP?

[ShawnD1]

Which video cards actually require 8x AGP to function at full speed?

My current computer has only 4x AGP. How far can I upgrade this thing before it starts bottlenecking?

to be honest no game as of right now off the top of my head takes full advantage of 8x


edited :P

[John Prophet]

yes, games shouldnt take advantage of other games...especially at 8x

J/k! lol

JP

[ShawnD1]

You mean it has to be coded IN THE GAME to use 8x? What about Windows Media Player?

The lower budget cards of today (FX5200) are bottlenecked a lot in 2x AGP so I was thinking maybe the high budget ones (which are at least 3x as fast) would be bottlenecked by 4x AGP.

In my P2 350mhz (2x AGP), a GeForce FX5200 is not much faster than a GeForce2 Ti200. In my AthlonXP 1700+ (4x AGP), the FX5200 is way faster than a Ti200. When watching a DVD, the CPU usage of the Athlon 1700+ with the Ti200 is like 30%. With the FX5200, the CPU is only used about 15% (whoa!). The difference in the P2 (2x AGP) is only like 5% CPU usage.

[The Terk]

thats too much math for a saturday night! lol, as long as you dont go with ati cuz ati uses a lot of cpu power to up the performance, cuz a 9800 pro will play completely different from a 1800+ (not as much fps) to a 3200+ (lots o fps!)

-edit... sorry guys, words got used wrong...ati rox, basically, the cpu itself is a bottleneck on vid cards (to an extent)

[ShawnD1]

Dude, by your post it sounds as if you have no idea how video actually works lol.

Against what you say, I would definitely get an ATI. Go to google and look for "nvidia directx 9 benchmark" and you'll see why.

[The Terk]

Originally posted by ShawnD1
Dude, by your post it sounds as if you have no idea how video actually works lol.

Against what you say, I would definitely get an ATI. Go to google and look for "nvidia directx 9 benchmark" and you'll see why.

:/ whateva.... i like atis better personally, and if u run a 9800 on a lower end system you arent goin to get the same performance out of it than a high end system.... dont hate...

[ShawnD1]

Originally posted by The Terk
if u run a 9800 on a lower end system you arent goin to get the same performance out of it than a high end system

*bangs head on desk*

Can I call you captain obvious?

[Kruzin]

1x,2x,4x,8x has nothing to do with the coding of any game, and has no effect whatsoever on video performance of movies or general desktop apps.
It simply reffers to the rate 3D textures and 3D vertex info can be transferred back and forth from system memory to video memory, if the memory on the card could not hold all the data.

Imagine a simple sine wave.
In the begining of AGP, information was transferred only during the rising edge of the signal. AGP 1x
Then they found they could transfer data at both the rising AND falling edges of the signal. AGP 2x
THEN they discovered they could also use the peaks and valleys to transfer data. AGP 4x
Then came DDR. DUAL DATA. Double it. AGP 8x

At this time, modern video cards have enough memory on-board to almost completely negate the effects of AGP transfer rates. Most games are still written to use <32meg of textures. When the video card has 64-128meg of memory on it, AGP tranfers will not even be used in most cases (there are a few games that use larger textures, and AGP rate will come into play on 64 meg cards).
If you run any benchmark on a card when it's in 2x mode, then again when it's in 4x or 8x mode, you will see no difference.
8x AGP is nothing more than a marketing tool, to make you think "gee...it MUST be twice as good as 4x...it's twice the number".

A more significant (and entirely unpublicized) factor in AGP performance is the difference between DMA and DiME AGP. ATI and NVidia use DMA. Matrox uses DiME. If you run a transfer rate comparison, you'll find DiME to be far superior in terms of AGP efficiency.

DMA = Direct Memory Access. When (IF) data is needed to be transferred to system memory, it is copied there until needed. When it's needed again, it's copied back to video memory and used.

DiME = Direct Memory Execute. When (IF) data is needed to be to system memory, it's copied there. When it's needed again, it's executed directly from the system memory, eliminating the extra step of copying it back to the video memory.

The difference between DMA and DiME is far more significant than the difference between 4x and 8x.
And when you're dealing with cards with 64, 128 or 256 meg of RAM on board, none of it really means a hill of beans.

It's all marketing.

[ShawnD1]

Thanks for the info.

That sounds good but it doesn't explain the situation I described. Look at my second post here to see the story.
The GeForce FX5200 is 128mb
The GeForce Ti200 is 64mb

Do DVDs require a higher AGP rate or something?