On Mon, Dec 1, 2008 at 6:33 AM, erik quanstrom <[EMAIL PROTECTED]> wrote: >> >> Very true, the only exception to this I know of is some of the modern >> Dual PCIExpress cards which use a bus in each direction. >> > > do you have a reference for "dual pciexpress"? as far as i know, > pcie/agp/pci cards only have a single bus that goes both ways.
how about this: "SANTA CLARA, CA—JUNE 28, 2004—NVIDIA Corporation (Nasdaq: NVDA), the worldwide leader in visual processing solutions, broadened its already expansive graphics line today with the introduction of four new NVIDIA Quadro(R) professional graphics solutions based on PCI Express™. Leveraging this next-generation bus architecture, NVIDIA doubles the bandwidth of its AGP 8X-based products to over 4GB per second in both upstream and downstream data transfers. " I think the AGP assymetry is long gone. Back when I was at LANL the graphics guys were telling me that read bandwidth was no longer an issue with the new pcie cards. If you're still seeing bad performance it may be because you need to fix up the MTRR or GART settings. I've done this dance and have no memory at this point of what you do, but vague memory is that proper MTRR settings with a good PCIe card will give you far better bandwidth than the old AGP cards. There is nothing like the 60x assymetry. ron
