Gast
2004-11-09, 12:35:22
Techreport schreibt zum Sideport-RAM :
There are very good reasons why Athlon 64 chipsets with built-in graphics aren't terribly common; chief among them is the Athlon 64's built-in memory controller. The on-CPU memory interface makes for very low latency memory access for the processor, but it raises memory access latencies for the rest of the system. A traditional north bridge, like on the Pentium 4, is more democratic, giving the CPU and a north bridge-based IGP roughly equal access to RAM. In order to work around the latency problems presented by the K8 system architecture, ATI has devised a unique scheme involving local frame buffer memory mounted on the motherboard and connected to the north bridge chip. The embedded RAM can come in the form of one or two memory chips. A one-chip config yields a 32-bit path to the local frame buffer RAM, while a two-chip config doubles up for 64 bits. ATI expects typical configs to include a one-chip, 16MB frame buffer or a two-chip, 32MB frame buffer.
Sollte das stimmen, dann wäre die max. Bandbreite des Side-Port RAM's höher als bei einer RV370 mit 64bit Bus.
Quelle: http://www.techreport.com/reviews/2004q4/radeon-xpress200/index.x?pg=2
There are very good reasons why Athlon 64 chipsets with built-in graphics aren't terribly common; chief among them is the Athlon 64's built-in memory controller. The on-CPU memory interface makes for very low latency memory access for the processor, but it raises memory access latencies for the rest of the system. A traditional north bridge, like on the Pentium 4, is more democratic, giving the CPU and a north bridge-based IGP roughly equal access to RAM. In order to work around the latency problems presented by the K8 system architecture, ATI has devised a unique scheme involving local frame buffer memory mounted on the motherboard and connected to the north bridge chip. The embedded RAM can come in the form of one or two memory chips. A one-chip config yields a 32-bit path to the local frame buffer RAM, while a two-chip config doubles up for 64 bits. ATI expects typical configs to include a one-chip, 16MB frame buffer or a two-chip, 32MB frame buffer.
Sollte das stimmen, dann wäre die max. Bandbreite des Side-Port RAM's höher als bei einer RV370 mit 64bit Bus.
Quelle: http://www.techreport.com/reviews/2004q4/radeon-xpress200/index.x?pg=2