32 vs 64 bit, need help buying a PCI card.

[Sam]

Hi All

I am looking at buying a PCI adapter/host card with SATA controllers and
possible RAID configurations to add extra SATA drives ( attached internally
with internal ports or externally with external ports).

One card specifies "Host side interface 32bit, 33MHz PC "

Another card specifies "The 64-bit PCI-X architecture ...., and operates up
to 133MHz...Host side interface
PCI-X 64bit (but retro compatible with ordinary PCI), 66/100+133Mhz "

Others talk about having a "64 bit engine" not specifying the "host side
interface"

I have a P4 3.2 GHZ running XP Pro and MOBO based on 875 chipset.AFAIK All
are 32 bit based?

Question : How do I know which is compatible with my pc? I am keen on the
PCI-X based card (PCI retrocompatable) just in case I do upgrade but unsure
whether my "host side" will support it?

(apologies for clumsy written question but I am rapidly getting out of my
technical depth)

Thanks

Sam

 

[Yves Leclerc]

A PCI-X slot is a lot longer than a standard PCI slot and may not be
compatible with the PCI-E slots. Most home PCs are getting PCI-E slots and
most server based PCs have PCi-X slots.

 

[John R Weiss]

I have a P4 3.2 GHZ running XP Pro and MOBO based on 875 chipset.AFAIK All are
32 bit based?

Question : How do I know which is compatible with my pc? I am keen on the
PCI-X based card (PCI retrocompatable) just in case I do upgrade but unsure
whether my "host side" will support it?

It depends on the individual card as well as your MoBo and case physical setup.

First, PCI-X slots can take 32-bit PCI cards as well. However, you have to
check the MoBo docs to ensure that using a single 32-bit card won't drag down
the whole bus to 32-bit bandwidth.

Second, some PCI-X cards are designed to work in PCI-X or 32-bit PCI slots
(e.g., Adaptec 29160 SCSI cards). The extra connectors merely overhang beyond
the end of the 32-bit slot. IF the MoBo has the space beyond the slot to
accommodate the connector strip AND your case setup allows the [longer] card to
fit, you can use the card in the 32-bit mode.

Finally, PCI Express is NOT compatible with either of the others. If you want
max flexibility in selecting add-in cards in the near future, don't buy a MoBo
with PCI Express only.

 

[Sam]

Okay and many thanks,

Sam

I have a P4 3.2 GHZ running XP Pro and MOBO based on 875 chipset.AFAIK
All are 32 bit based?

Question : How do I know which is compatible with my pc? I am keen on the
PCI-X based card (PCI retrocompatable) just in case I do upgrade but
unsure whether my "host side" will support it?

It depends on the individual card as well as your MoBo and case physical
setup.

First, PCI-X slots can take 32-bit PCI cards as well. However, you have
to check the MoBo docs to ensure that using a single 32-bit card won't
drag down the whole bus to 32-bit bandwidth.

Second, some PCI-X cards are designed to work in PCI-X or 32-bit PCI slots
(e.g., Adaptec 29160 SCSI cards). The extra connectors merely overhang
beyond the end of the 32-bit slot. IF the MoBo has the space beyond the
slot to accommodate the connector strip AND your case setup allows the
[longer] card to fit, you can use the card in the 32-bit mode.

Finally, PCI Express is NOT compatible with either of the others. If you
want max flexibility in selecting add-in cards in the near future, don't
buy a MoBo with PCI Express only.