Gigabit Connections

By dani_17
Feb 19, 2003
  1. Hi There!

    I want to upgrade the network at my house, currently 100Mbps to 1000Mbps Gigabit Ethernet.

    I need to buy a new switch but I have 2 questions:

    - Can cat5 cabling do the job or do I need cat6?

    - All the Gigabit NIC's I've seen have 64bit PCI interface. I don't have 64bit pci's in my motherboard. What am I suppose to do?

    Just want to have those 2 things cleare before buying the wrong stuff. :)
  2. conradguerrero

    conradguerrero TS Rookie Posts: 310

    do you have cat 5 or cat 5e?
  3. MrGaribaldi

    MrGaribaldi TechSpot Ambassador Posts: 2,512

    There are several gigabit nic's available with PCI(32)...

    I.e. this one, which also supports 100mbit...
  4. Mictlantecuhtli

    Mictlantecuhtli TS Evangelist Posts: 4,345   +11

    The problem with 32-bit PCI bus and gigabit NICs is that the PCI bus doesn't have enough bandwidth for the NIC to operate at full speed. If I remember correctly, the maximum bandwidth for 32-bit, 33 MHz PCI bus is 133 Mbps, not much more than what 100 Mbit NIC could do.
  5. dani_17

    dani_17 TS Rookie Topic Starter Posts: 146

    All my cables are cat5, not cat5e.

    Also Mictlantecuhtli, pci has 133 MB/s maximum theoretical bandwidth, wich is very diferent than 133Mbps.

    I took a look at that SMC9452TX. I think I'm going more for a NIC with a Intel chipset, or even better, a 3Com. But precisely those are the ones I only found in 64bit-PCI. I'm not sure, but is it possible to plug in a 64bit-PCI card to a normal 32bit Pci slot?
  6. Mictlantecuhtli

    Mictlantecuhtli TS Evangelist Posts: 4,345   +11

    Ah yes, I didn't remember correctly then. True, that's a theoretical maximum, motherboards have some latencies and different overheads slowing it down to about 90 MB/s.

    It depends on the card whether you can use it in 32-bit slot or not, in general I'd say if the card can fit into slot, it should be compatible with it, too.
  7. Rick

    Rick TechSpot Staff Posts: 4,573   +65

    I read the typical real-world performance of 32-bit PCI is somewhere around 112mb/sec 120mb/sec depending on your equipment. This is just about perfect for a 1Gbps connection, as that is probably somwhere around 120mb/sec.

    Most computers are not capable of transferring that much data. Only servers would have disks fast and abundant enough to sustain that kind of a transfer rate.

    100Mbps is somewhere around 12mb/sec.. Which isn't great, but for home networking is plenty. The move to 1Gbps is your move though. :) It will be useful if you have an unusual amount of computers on your network, or transfer large files regularly (videos, archives, backups etc..)

    Modern IDE disks move about 40mb/sec sustained, so a 100Mbps network IS a bottleneck, but 1GBps is overkill.. I wonder why no one made a 500mbps connection? :)

    64-bit PCI cards should be compatible with 32-bit PCI bus, shouldn't they? I haven't heard otherwise.
  8. dani_17

    dani_17 TS Rookie Topic Starter Posts: 146

    Well, I guess the reason for why they didn't do 500 Mbps is the same as why they didn't do a 50 Mbps one... cause for most users 10 Mbps is sufficient. 100 Mbps is also sufficient for the ones that need performance. And finally, 1000 Mbps are for us the crazy ones :)

    I've read in reviews of some 3Com cards that the 64bit pci cards are compatible with the 32pci slots but they loose performance. I couldn't get how much it looses. Anyway, as you said, a desktop computer with normal hdd system with no RAID or SCSI the performance lost by the speed of the transfer between the hdd and the motherboard is bigger than the one lost by the pci-64 and the pci-32.

    Anyway I'm still looking for information
  9. MrGaribaldi

    MrGaribaldi TechSpot Ambassador Posts: 2,512

    Here's an Intel gigbit card which supports 10/100/1000mbit and PCI 2.2...

    But it doesn't say anything about the performance difference...

    But it shouldn't be too big, as the pci bus is (supposed) to handle a maximum throughput of 200mb (half duplex)...

    Read around here for more info...
  10. zygon

    zygon TS Rookie

    I have a 32-bit PCI ethernet card is that a fast card????? for dsl??
  11. Mictlantecuhtli

    Mictlantecuhtli TS Evangelist Posts: 4,345   +11

    It's fast enough if you only use it for DSL.
  12. Phantasm66

    Phantasm66 TS Rookie Posts: 5,734   +7

    Here's a great article over at Toms hardware which will tell you plenty!

    He seems to think that 1000Base-T is COMPLETE OVERKILL unless you are doing something pretty serious. Even streaming video from a home media server to some workstation connected to a TV or something should be fine with 100Mpbs.

    More notes on 1000Base-T - do you need it? here.
  13. Phantasm66

    Phantasm66 TS Rookie Posts: 5,734   +7

    Another good point here:

    Especially bare the last point in mind. The TCP/IP stack in Win9x is not designed for these kinds of speeds.
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