Real life AGP bandwidth? how much is actually being used

[13thmonkey]

I know that AGP 8x is 2.1Gb/s and that PCI-E is twice? that or that just for 1 channel I can't recall right now.

But the real question is does anyone know how much bandwidth is actually being used on BF2/X3 splinter cell for instance.

I'm sure that you can guess I've got a Socket A system, and I'm thinking of the final upgrade to keep me going, i.e. that Gainward, or possibly the other Gainward, but I'd like to know if the AGP bandwidth is actually saturated in real usage, it'd just give me that bit more knowledge to make what I'm sure will be a dumb decision.

(Un)fortunately (from a path point of view) I have a Barton 3200+ which I am sure is meaty enough for a while with a decent card (currently a 6600GT) with 2x1Gb of PC3200, so the upgrade will be a mobo, a CPU, possibly a PSU (enermax 485W that squeals a bit when it starts) and a GPU, so its a £500+ upgrade Vs a £350 card.

The CPU upgrade is not that enticing as I'm not going to get that much real world power out of it, I don't mind waiting for an extra 30secs for the 2-3 MP3 rips per week, although dual core would be nice but that'd push the £500+ to £650+. And whilst I enjoy building PC's I'm not going to get that much extra poke out of it? Of course if I wait for AM2, then my DDR will be useless and I'll need memory as well, so if this pushes me another year then that'll be great.

Any takers, anyone know of any software that'll tell me whats happening on the AGP bus? Would the 512Mb that the card offers mitigate the lower Bandwidth by not forcing the card to use system memory? What is that bandwith actually used for, i.e. geometry calcs are on-card? most calcs are on-card so is it 'just' the world dump at the start of the 'level'? and all updates as the CPU works out all the interactions with the rest of the world and inside the world?

I think I've rambled a bit, I'll stop now. Thanks for any help....

 

[HourofDarkness]

wherever the bottleneck is, its definately not the graphics card.
try turning down AGP to 4X. there's NO DIFFERENCE in framerate whatsoever, and the problem comes only when its down to 2X. (EVGA 6800GS)

it means that the 6800GS' running at lower than 50% bandwidth. dunno why nvidia and ati dropped agp so early, coz if its running at lower than 50% bandwidth then there wont be a problem with transfer speed until, say, 8900GTX?

 

[illicitsc]

they dropped agp so that u have to get a new video card to go along with their new chipsets. which are only available on pcie.. goddam corporate bastards

 

[bum_jcrules]

Several reasons...

1. AGP is limited in the amount of power it can deliver by itself

2. PCIe is far more scalable than AGP in terms of overall system configurations

3. One more way to make people buy new stuff

 

[JonathanDeane]

Yeah I sure would love to see a game using 2GB's a second of bandwidth.... lol would make HL2 look like pong...

 

[the_guru]

wherever the bottleneck is, its definately not the graphics card.
try turning down AGP to 4X. there's NO DIFFERENCE in framerate whatsoever, and the problem comes only when its down to 2X. (EVGA 6800GS)

it means that the 6800GS' running at lower than 50% bandwidth. dunno why nvidia and ati dropped agp so early, coz if its running at lower than 50% bandwidth then there wont be a problem with transfer speed until, say, 8900GTX?

They dropped AGP for two reason.

1. The old PCI-bus needed to be replaced and it was easier to design PCI Express to include the graphic card bus as well.

2. They wanted to earn more money.

 

[13thmonkey]

Thanks to everyone, and not a flame in sight, I guess some people were asleep

It was as I kind of expected, AGP is not really a bottleneck, I'd also figured that FPS does not scale particularly well with processor speed, although I was unsure if my sources used the same setup, but it they did not then it probably scales even less.

So the card is the primary driver for FPS (duh) but it is seperate from the bus.

I was considering turning down the AGP multiplier but didn't want to do it in hardware, I've killed one card (another 6600GT) running it on a 4x only board already.

Wusy, you say that the 7800 has too much power, I assume that that goes for the 7900GT on a 7800 AGP board as well? however the choice is 6800's (don't the 7XXX have a better feature set?) or a 7800/7900 7900 is cooler/lower powered, so seems like a better choice long term. My plan for the next big upgrade is late 2007 early 2008 when the mud has settled over conroe and K10/11 or whatever they will call it and I don't want to miss the last (possibly) AGP cards.

 

[JonathanDeane]

I think they actualy disabled some pipes for the AGP version of the 7800 Dont quote me on that but if thats not it then Nvidia's converter chip is to blame ?