Tenchusatsu,
Herr Uberclockermeister, once a vocal critic of AGP, later changed his mind and said, "AGP vs. PCI is a question that doesn't need to be asked anymore today. AGP has succeeded in the upper performance area quite a while ago already."
AGP has succeeded at having higher bandwidth than PCI, because of the same reason that a $11.50 bill would be higher value than a $10 bill, but that's hardly an endorsement of the logic that would go into issuing $11.50 bills.
By the way, try downloading 64 MB of textures over a 133 MB/sec (or worse, 100 MB/sec effective bandwidth) PCI bus.
But that's not the premise of AGP. The premise of AGP is that some textures are stored in main memory and accessed by graphics card from there, which is a complete joke, and shows a complete lack of foresight by the Intel designers. (these same people apparently "guess" the future of where computing will be going with their P4 and Itanium designs that are at best bets at worst shots in the dark).
Let's see how their prediction turned out. For an idiot software designer who listened to Intel, he would have software today, that accesses textures from a the main memory with bandwidth of 500 MB/s (Celeron system), with hell of a latency caused by AGP transfer instead of > 5 GB/s bandwidth local memory of the graphics card with an order of magnitude lower latency.
Your 64 MB of textures are not realistic at all. Maybe the whole game may have that many of textures, not a scene, and a typical game on a PC with say 64 MB of main memory will have only a small fraction of this data in memory, so the theoretical transfer rate of AGP is irrelevant if the data is going from the hard disk. (Hmm, disk -> PCI disk controller -> PCI bus -> AGP bus -> AGP graphics card is probably even slower than disk -> PCI disk controller -> PCI bus -> PCI graphics card)
Also, Intel already had a spec for a general purpose bus in place that fulfilled all the realistic expectations of a graphics industry (not the idiotic ones of the AGP designers) in PCI 33/64 and PCI 66/64. Under the normal evolution, the graphics industry would drive the acceptance of these general purpose technologies, and a typical PC would today have a bunch of these slots instead of almost decade old PCI classic slots.
From the technical perspective, AGP is an inexcusable piece of garbage.
Joe |
