?

Fafalada said:
Depends on the game I guess - in our game(on PS2) we around 70% of free memory for graphics on average. Textures taking around 2/3s of that.

Fox5 said:
What about Gamecube? Flipper's access to its main memory isn't any faster than agp 8x.
Not sure what speed would have to do with?

Well, flipper's access to main memory isn't any better than a modern pc video card's access to main memory, so can you really say that gamecube's memory can be treated as one big block(especially when you have 3 memory groups with very different speeds) while a pc's video and main memory is distinctly seperate?
 
IST said:
AGP8X has a maximum of 4.2 gigs of bandwidth. It isn't fully utilized, IIRC.

Ok, well then gamecube has a bandwidth of agp4x then.

Are you sure it's 4.2gigs? I thought that was pci express...
PCI @ 33mhz = 133MB
so AGP @ 66 mhz = 266MB
x8 = 2128MB

Wouldn't you need agp16x for 4.2gigs? And the AGP bus can be very easily fully utilized, say if a graphics card had to run with little or no memory at all. Or how about a r3xx card running the ruby demo? That thing takes up 249MB with compression on the r420 cards, I'd think the more intensive scenes could easily tax the agp bus on an r3xx card.
 
2GB/sec for AGP 8x... However getting use out of it isn't all it's cooked up to be... Unless you're running OS X, most drivers (both GL and DX) texture DMA performance is abysmal, there's a lot of latency on the bus and turn-around time is horrid (things which PCI-E look to fix, or at least fix some of)... Granted a lot of this has to do with driver implimentations, OS and API support, and how your apps leverage the API/Framework for higher data throughput...
 
Fox5 said:
IST said:
AGP8X has a maximum of 4.2 gigs of bandwidth. It isn't fully utilized, IIRC.

Ok, well then gamecube has a bandwidth of agp4x then.

Are you sure it's 4.2gigs? I thought that was pci express...
PCI @ 33mhz = 133MB
so AGP @ 66 mhz = 266MB
x8 = 2128MB

Wouldn't you need agp16x for 4.2gigs? And the AGP bus can be very easily fully utilized, say if a graphics card had to run with little or no memory at all. Or how about a r3xx card running the ruby demo? That thing takes up 249MB with compression on the r420 cards, I'd think the more intensive scenes could easily tax the agp bus on an r3xx card.

PCI Express can send 8GB in one transaction (4GB to the videocard and 4GB from the videocard) whereas you're limited to 2GB in only one direction with AGP8x.
 
Besides, AGP is only used when sending data to the card. Consumer video cards only support read back at PCI -speed. 3DLabs has fast read back though, don't know about Quadros and their ilk..
 
GameCat said:
Besides, AGP is only used when sending data to the card. Consumer video cards only support read back at PCI -speed. 3DLabs has fast read back though, don't know about Quadros and their ilk..

Really. I wasn't aware of that. Man AGP sucks even harder! :LOL:
 
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