- Joined
- Aug 1, 2003
- Location
- Round Rock, TX
I was reading up on the new Intel Chipsets and had various questions I couldn't find answers on.
Intel i875P Chipset
Following the diagram I see that the maximum bandwidth available to the 800MHz Pentium 4 is 6.4GB/s.
The Northbridge (MCH) consists of the Dual Channel DDR400 Memory Bus at 6.4GB/s, the AGP 8x Bus at 2.1GB/s, the CSA GbE Bus at 266MB/s, and the Hub Interface 1.5 at 266MB/s which connects to the Southbridge. This adds up to around 9GB/s of total Bandwidth. Why isn't the bandwidth available to the CPU 9GB/s instead of 6.4GB/s? This appears to me to be a huge bottleneck. How does the CPU communicate with the various buses? (Link or Article would suffice).
The Southbridge shows to have independent Buses for Audio, SATA, PATA, LAN, PCI, and USB. I thought that the PATA, Audio, USB, and LAN all shared bandwidth with the PCI Bus. Do these in fact have independent connections to the southbridge or is the diagram misleading? The diagram also shows a Dual Independent SATA Bus running at 150MB/s. Does this mean that both SATA channels/drives must share the 150MB/s Bus? If so, doesn't that limit the maximum throughput of 75MB/s to each drive or is there 150MB/s dedicated to each channel/drive? In addition, if the SATA Bus alone is using 150MB/s and the PCI is using 133MB/s that would exceed the 266MB/s Hub Inteface by 20MB/s which would limit the SATA Bus down to 133MB/s before even counting any bandwidth being used by USB 60MB/s max, Audio ?, LAN 12.5MB/s Max, etc. Am I looking at this all wrong or are we being mislead by marketing? Why is the Hub Interface Bandwidth so small when the devices on the Southbridge exceed the needs of the connection?
Is the Intel ICH5 SATA Controller seen as an IDE Controller in the OS? Are SATA Drives connected to the ICH5 affected by the Write Cache Performance Degradation Issues like SCSI Drives and IDE RAID are in Win2K SP3+ and WinXP? If so is this only when running in RAID or also when the drives are used independently?
I need enlightenment...
Thanks,
-Josh
Intel i875P Chipset
Following the diagram I see that the maximum bandwidth available to the 800MHz Pentium 4 is 6.4GB/s.
The Northbridge (MCH) consists of the Dual Channel DDR400 Memory Bus at 6.4GB/s, the AGP 8x Bus at 2.1GB/s, the CSA GbE Bus at 266MB/s, and the Hub Interface 1.5 at 266MB/s which connects to the Southbridge. This adds up to around 9GB/s of total Bandwidth. Why isn't the bandwidth available to the CPU 9GB/s instead of 6.4GB/s? This appears to me to be a huge bottleneck. How does the CPU communicate with the various buses? (Link or Article would suffice).
The Southbridge shows to have independent Buses for Audio, SATA, PATA, LAN, PCI, and USB. I thought that the PATA, Audio, USB, and LAN all shared bandwidth with the PCI Bus. Do these in fact have independent connections to the southbridge or is the diagram misleading? The diagram also shows a Dual Independent SATA Bus running at 150MB/s. Does this mean that both SATA channels/drives must share the 150MB/s Bus? If so, doesn't that limit the maximum throughput of 75MB/s to each drive or is there 150MB/s dedicated to each channel/drive? In addition, if the SATA Bus alone is using 150MB/s and the PCI is using 133MB/s that would exceed the 266MB/s Hub Inteface by 20MB/s which would limit the SATA Bus down to 133MB/s before even counting any bandwidth being used by USB 60MB/s max, Audio ?, LAN 12.5MB/s Max, etc. Am I looking at this all wrong or are we being mislead by marketing? Why is the Hub Interface Bandwidth so small when the devices on the Southbridge exceed the needs of the connection?
Is the Intel ICH5 SATA Controller seen as an IDE Controller in the OS? Are SATA Drives connected to the ICH5 affected by the Write Cache Performance Degradation Issues like SCSI Drives and IDE RAID are in Win2K SP3+ and WinXP? If so is this only when running in RAID or also when the drives are used independently?
I need enlightenment...
Thanks,
-Josh
