Originally posted by: CyberZenn
Originally posted by: Lurker1
you can easily saturate a 100Mbps network with 2 computers. That's only 12.5MBps.
Gigabit will get you a theoretical max of 125 MBps, which is still less than the theoretical 133MBps max of a PCI bus.
Yes, but remember that the PCI bus is shared between all of your PCI devices and, depending on your motherboard architecture, most of your integrated devices as well. You need a 64bit/66mhz PCI slot to take take full advantage of gigabit ethernet w/ most x86 based systems.
Depends on how your system is setup. A file server may only have video, disks, and a network adapter on two PCI buses, or some or all may be integrated and shared, or not shared.
A 64bit 66MHz bus will peak at ~528MBps. A 64bit 33MHz bus will peak at ~214MBps. The true benefit of 64 bit buses is that they're a separate subsystem than your 32 bit bus, although I do not know explicitly how that translates into data transfer between the PCI buses, the bridges, cpu, and memory. It's been a little too long since I looked into those aspects.
However, being able to make use of Gigbit does not require 64bit PCI buses. It more accurately depends on what you're doing, since you could be accessing an in-memory DB or generating large amounts of information via requests that have nothing to do with disk access. In those cases, the PCI bus issues may not even crop up, and you could saturate a Gigbit network with even a standard PCI bus hard disk system.
As a final note in the case of files, file transfer speed is limitted by disk data transfer speeds. That ATA133 does not do continuous data transfer at 133 MBps. Nor does scsi. To actually hit continuous data transfer speeds in that range requires RAID 0 or 5 (most common 2) with the appropriate number of disks in the appropriate configuration to support the continuous transfer at 125MBps +. For a SCSI RAID 5 system consisting of a single U320 channel with 3 15K drives in RAID 0 could conceivably support Gigabit throughput. However, this is extremely dependent on the disks used, file system organization, etc.