PCI-X RAID card in a PCI 64-bit slot

Discussion in 'NZ Computing' started by Ray Greene, Mar 2, 2010.

  1. Ray Greene

    Ray Greene Guest

    I'm thinking of putting a PCI-X SATA-2 RAID card in a mobo with a
    standard PCI 64-bit 33MHz 3.3v slot. I think I've read somewhere that
    this will work, but I'm happy to be corrected. Obviously the bus speed
    will be lower than PCI-X.

    Assuming it does work, does anyone know what hard drive performance
    I'm likely to get, any chance I'll get the full 3Gb/sec?
    Ray Greene, Mar 2, 2010
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  2. Ray Greene

    EMB Guest

    There's no such thing as a 33MHz 64-bit PCI slot.
    Assuming you mean a 133MHz, 64-bit PCI-X slot then maximum throughput is
    ~ 1GB/s
    EMB, Mar 2, 2010
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  3. Ray Greene

    David Empson Guest

    Apple's PowerMac G3, G4 and (low end) G5 used them from 1999 until 2005
    and the developer documentation describes them as an "industry
    standard". (Apple used to PCI-X in higher end PowerMac G5 models from
    2003 to 2005, and moved to PCI Express in 2005.)

    Wikipedia mentions 64-bit and 33 MHz as a supported combination, but
    suggests that in the Windows/Intel world, 64-bit was rare outside of
    server configurations.

    The 64-bit slot is of course compatible with 32-bit PCI cards.

    Ray - I don't know know if PCI-X cards are always compatible with PCI
    slots. It may depend on the specific card, i.e. whether it is designed
    to cope with the lower clock speed of PCI.

    (I have a SATA/eSATA card in my PowerMac G4 that says it is designed to
    work with both PCI and PCI-X slots.)

    64-bit 33 MHz slots will give maximum throughput of about 2.1 Gbps,
    assuming the PCI bus is otherwise unused. 64 bits x 33MHz = 2112 Mbits
    per second.

    You can't get the full throughput of a single SATA-2 channel via 33 MHz
    PCI. (You could do it if you had 64-bit 66 MHz PCI, but that is probably
    very rare.)
    David Empson, Mar 2, 2010
  4. Ray Greene

    Ray Greene Guest

    Ray Greene, Mar 2, 2010
  5. Ray Greene

    Ray Greene Guest

    OK, I'll see if I can find the specs of the RAID card.
    That would be a respectable speed all the same. I'd be quite happy
    with 1.5 Gb/sec.
    Thanks for the info. I'll probably go to PCI-e at some point but for
    now I'm just trying to build a cheap NAS box from parts that are lying
    Ray Greene, Mar 2, 2010
  6. Ray Greene

    ~misfit~ Guest

    I was building a few systems and poking around in even more about then and
    never saw one of those in the wild. So they actually let a few go huh?
    Do you already have the card (or have a place where you can get it)? As I
    understand it the slots weren't common so likely the cards weren't either.
    If you don't already have it and you're building a NAS box it might be best
    going for a cheap[ish, it never pays to go too cheap IME] mATX socket 775
    board with PCIe from the start. Those dual-core Celerons are unbelieveable
    value / processing power for the money and have a very low thermal output.
    In fact the HDDs are likely to need more cooling than the CPU.
    ~misfit~, Mar 2, 2010
  7. Ray Greene

    Ray Greene Guest

    Well, two made it to my place anyway. I've seen a few others around.
    They're not flash but they're bulletproof.
    There are some cards available dirt cheap, and that would be my only
    expense in getting started. Once I start spending on stuff I don't
    absolutely need I'll end up with the biggest, fastest, most expensive
    NAS box you've ever seen. That's what I'm trying to avoid :)
    Ray Greene, Mar 3, 2010
  8. Ray Greene

    Richard Guest

    There were several quite cheap cards based on the marvell chipset a few
    years back.

    Worked well so long as only one drive was being accessed at a time in a
    33MHz 32 bit slot, too slow otherwise for raid-5 in windows.
    Richard, Mar 3, 2010
  9. Ray Greene

    Ray Greene Guest

    The ones I'm looking at use a Silicon Image chipset. They seem to work OK,
    the only problem for me is that FreeNAS doesn't have drivers for them.
    OpenFiler does though so I guess I can lower my standards and use that
    instead :)
    Ray Greene, Mar 3, 2010
  10. Ray Greene

    ~misfit~ Guest

    Ahh, OK.
    Hehee! Yeah, that's a trap alright. However from what I've read about the
    speed of most consumer-level NAS boxes most anything you make will trounce
    an off-the-shelf unit. It just likely won't be as pretty.
    ~misfit~, Mar 4, 2010
  11. Ray Greene

    ~misfit~ Guest

    Ok, something I missed completely. Then again, it's hardly the sort of thing
    that I was working with. I mainly made gaming rigs for friends.
    Yeah, standard PCI is quite a bottle-neck, slowing down even a single SATA
    drive using a PCI controller. PCI-X is something I have no knowledge of. I
    guess I should have just STFU in the first place. However with *real*
    computer threads being so rare here these days it's hard not to get excited
    when I see one. ;-)
    ~misfit~, Mar 4, 2010
  12. Ray Greene

    Ray Greene Guest

    Whaddya mean?? There's nothing prettier than a Compaq server! :)

    Actually I've got a very ugly old server case here that'll take 10
    drives. I'm thinking about putting the Compaq mobo in it and just
    adding more drives as finances allow. I could end up with some serious
    storage capacity.

    You're right about performance. We've been using D-Link NAS boxes at
    work, but as they got fuller they got slower until the point where a
    backup was taking nearly a full day, even when there were very few
    files to copy. Just doing a file compare on nearly a terabyte worth of
    files overloaded it. Apparently it's the CPU that can't keep up, they
    have a 1Gb/s NIC.

    I built a couple of boxes from old PIII 800s with Gb NICs running
    OpenFiler or FreeNAS and they'll happily do the same backup in around
    two hours.

    The wee D-Links are great but they just don't have the grunt for
    serious work.
    Ray Greene, Mar 5, 2010
  13. Ray Greene

    Ray Greene Guest

    Here, use my hankie :)
    If there's one thing in the world that's guaranteed to be futile, it's
    trying to keep up to date with computer hardware. The last time I
    tried I blew nearly $5000 on a reeeally fast 486...
    These days I just select my software carefully and don't install any
    crap, and my old dunger is generally nearly as fast as and more
    reliable than most PCs I see that are 6 months old or more. They
    always start off fast but seldom stay that way for long.
    Ray Greene, Mar 7, 2010
  14. Ray Greene

    ~misfit~ Guest

    Thanks. ;-)
    Heh! The last new computer I bought was a $5K 486! Since then I've pretty
    much either used second-hand machines or built my own.
    Agreed. However this machine was bought with an eye to the future, built
    with a pretty good mobo. The C2D was only supposed to be temporary, to be
    replaced with a fast C2Q when they got cheaper but before they got phased
    out, I guess I need someone in the industry watching prices to let me know
    when / before Skt 775 stuff starts going up in price as it'd no longer

    In the past I wouldn't have needed anyone to tell me but now I'm no longer
    building machines and have migrated to laptops myself I no longer 'have my
    finger on the pulse' as it were. It would be nice though to have this
    desktop machine achieve it's destiny, what I designed it to achieve; Run
    with a fast 45nm quad-core CPU. The case, the cooler, the mobo, the PSU...
    Everything was chosen with that in mind.

    Ticking away the moments that make up a dull day...
    ~misfit~, Mar 7, 2010
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