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OT: PCI vs. PCI-X for added serial ports

Discussion in 'Electronic Design' started by Eeyore, Aug 6, 2007.

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  1. Eeyore

    Eeyore Guest

    Since the data rate to a serial port is so fabulously low, why are you worried
    about a card slowing your system down ?

  2. Hi, I'm looking at getting a new workstation with an Asus P5K
    motherboard. There appears to be a single COM port header on the
    motherboard, but no rear bracket to connect to it. In the event I have
    to add ports on a card (to support various embedded programming stuff,

    I'd like at least two working serial ports, so the same computer can
    talk to a target system as well as one tool) should I get a PCI card
    or one of the newer (and generally quite expensive) PCI-X cards? Since
    it won't get used that much on average, I'd be unhappy if it slowed
    down the system. I'll be using WinXP Pro, if that matters.

    Best regards,
    Spehro Pefhany
  3. Guest

    Wouldn't you want to save your PCI-X slots for something sexy like a
    raid card?

    You can always go the usb to serial route. I used to be very
    particular about these devices since early in the game only Keyspan
    had a converter that would work with my scanner radios and gps. But
    lately even the cheap Airlink 101 converters drive my serial devices.

    If you really wanted to be bullet proof, I'd get the plain PCI card.
    If for some reason you wanted to set up a DOS partition (don't laugh),
    PCI would be more likely to work since PCI-X came out after they
    stopped updating DOS. [There are programs that run under DOS to get
    around the huge latency of a serial port under windows.]
  4. If a $20 serial card slowed down the bus to my PCI-Express x16
    graphics card, and thus crippled the CAD display performance, I'd be
    majorly p*ssed.

    Best regards,
    Spehro Pefhany
  5. Guest

    Howdy Spehro,

    USB to RS-232 adapters are less expensive than that, and they won't
    take up either kind of precious PCI slot.

    The hardest part is that there are so many to choose from...

  6. Eeyore

    Eeyore Guest

    I don't understand why you think that's likely to happen though.

  7. Can they typically be trusted to work with hardware handshaking? I've
    heard of a lot of compatibility issues.

    Best regards,
    Spehro Pefhany

  8. 12 USB ports, and one COM port that you have to buy a cable & filler
    plate to use? They don't list the pinout in the manual, at least where
    the other pinouts are shown, with the connector locations. The external
    SATA connector might come in handy.

    It requires a 24 pin ATX 400 W power supply, or a 500 to 600 W supply
    if you use the PCI-X slots. (2.56 MB) 150

    Service to my country? Been there, Done that, and I've got my DD214 to
    prove it.
    Member of DAV #85.

    Michael A. Terrell
    Central Florida
  9. Guest

    The keyspan I have has a "hardware compatibility" mode, which does
    handshaking. However, I know the cheap Airlink 101 does handshaking
    too. I think the deal is the current generation chips have the bugs
    worked out.

    The first generation converters were not field tested very well. I had
    to return two before I found one that worked with my GPS.

    I have one usb device that uses FTDI chips. I like this vendor since
    they support many OSs. [I'm running X64 at the moment.] I've had good
    luck with this company, though I haven't used their usb to serial
    converters. Give their tech support a call.

    They also sell PCI serial cards.
  10. Until you drop it.
    Unless your data is worth zero.
  11. I can use 8-9 to start with. 1-2 printers, modem, mouse, keyboard,
    ICD, Spaceball, scanner, and a card reader.
    Yes, eSATA or whatever they're calling it. Good for backup- just plug
    in a ~$100 500G drive in an inexpensive enclosure. That's cheaper than
    recordable Blu-ray disks even if you never erase the HDD!
    I've got a 620W Corsair/Seasonic on order to handle the relatively
    modest 65W video card and a small RAID setup.

    *Oopsie. I notice I've confused the name PCIe (PCI-Express) with the
    older PCI-X (PCI-eXtended). It's the former.*

    I was astonished to see some of the insanity of the high end "gamers"
    SLI- using *two* (or *gasp* more) video cards that could cost
    thousands each and use hundreds of watts each to operate a single
    monitor. Oh well, if it drives better and cheaper CAD-capable cards
    then it's a good thing.
    Thanks for the link.

    Best regards,
    Spehro Pefhany
  12. Eeyore

    Eeyore Guest

    I'd recommend external NAS storage actually. The enclosures c/w controller are
    getting very inexpensive now and for a bit more you can get RAID versions too.

    It's what I'll be looking at buying before long.

  13. Eeyore

    Eeyore Guest

    There's a thought ! It makes some sense.

  14. Yes, that would work, you'd always need 2 in circulation perhaps.
    I dropped a HD and lost all data on it (I did not go so far
    as to have the data rescued from it by some company).
    I dropped a map with about 400 DVDs and nothing happened except the boink noise.
    It sure is faster to copy to some HD then write say 30 Blu-Ray disks.
  15. Use a new drive every month. Keep the old ones.

    Best regards,
    Spehro Pefhany
  16. Sure, although I found some of the inexpensive enclosures from
    tigerdirect would not handle NTFS file systems in NAS mode (only USB
    mode) so they were effectively useless for any decent amount of
    How do you keep a backup off-site with a NAS box?

    Best regards,
    Spehro Pefhany
  17. Eeyore

    Eeyore Guest

    I thought the whole thing about NAS was that it avoided such problems.

    I don't.

    If my home burns down, I'll be worrying about other stuff. Of course it's unlikely
    to burn down since it's the UK.


  18. All my systems still have the PS/2 keyboard/mouse ports, and I have
    printers scattered all over the network, (Including some real oldies,
    like the IBM 4019 laser printers) so so far I have only needed one, four
    port hub to keep from using the front panel USB ports on the old Windows
    ME computer I use to stream WSM online. It started out as an Emachines
    733 E-Tower, which was the last new computer I bought, while i was
    working. It is on its second used motherboard, from the pile of
    un-repairable computers I rebuild.

    That should do it.

    No biggie, unless you order the wrong boards. :)

    I think the amount they spend on a gaming computer is a direct
    reciprocal of their remaining brain cells.

    You're welcome. A lot of the time its quicker to find the MB manual
    at Tiger Direct, rather than the OEM sites. BTW, I have archived a lot
    of MB manuals, because they have a short online life.

    Service to my country? Been there, Done that, and I've got my DD214 to
    prove it.
    Member of DAV #85.

    Michael A. Terrell
    Central Florida
  19. I think that's a very good idea.. a couple of times I've run into
    problems where a PS/2 keyboard has gotten me out of. Not sure what
    would have happened if the motherboard had no PS/2 port. You can work
    around having no mouse, but not a missing keyboard. Asus seems to
    agree- this one has a keyboard PS/2 but not a mouse.
    I've got an old Gateway like that. Only the case and power supply is
    original. Built like iron. It still works fine browsing the web or
    Yes, I keep whatever I can get on disk for products I own. A couple of
    times my IT consultant neighbor has given me a left overcomputer and
    I've usually been able to find manuals online, but it's not

    Best regards,
    Spehro Pefhany
  20. Guest

    Modern boards have PCI-Express X 16 and PCI-Express X 1, plus the
    older PCI 2.3
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