Yes, a PCIe x4 x8 x16 will work in a PCIe x1 slot, if the PCIe x1 slot has an open end or if the daughter card has the appropriate notch cut out, but plugging a PCIe x4 x8 x16 compatible card into a PCIe x1 slot will then only work at PCIe x1 speeds.
Chances are the the Intel NIC will fit into and work just fine in the 2nd PCIe x16 slot on your mobo. Just because they say the 2nd x16 PCIe slot is for another graphics card does not necessarily mean that it's the only thing you can use it for. It just means that it's paired with the 1st x16 PCIe slot for an X-Fire/SLI set-up as opposed to other available PCIe slots on the mobo.
However to be sure that the NIC will work in your mobo, provide the make/model of your mobo as well as the make/model of the NIC.
As Merlinbadman asked, doesn't your mobo have onboard NICs?
> then, i was going to insert a intel nic card with 2 ports, to allow for double the transmission from the servers...
A Gigabit switch should be fast enough that
you don't need to use 2 ports to do "teaming".
In our LAN, I've spent many hours just watching
the Networking tab in Task Manager, and
the raw transmission rate through any given
NIC is much more heavily influenced by delays
caused by accessing spinning hard drives
and searching the file systems at both ends.
It's only when my tasks involve copying
relatively large files, e.g. drive image backup of C:,
that we see really high transmission rates
through our Linksys Gigabit switch.
Similarly, if a source file is already in RAM,
the transmission rate goes UP quite a bit:
this again indicates that low transmission
rates are probably due to hard drive delays.
Here's something else to consider:
try to "segment" your network utilization
into low-speed and high-speed groups.
Print tasks would fall into the low-speed group,
for example: adding more internal memory
to your printer, e.g. HP LaserJet, will also
result in faster print services.
If your network does any sort of transaction
processing, then assign those tasks to the
high-speed group e.g. calling up the medical
records for any given patient, especially
while they are waiting on the phone
and/or when a physician needs to see
Thus, focus on accelerating READs
because your 14 clients most probably
do READs much more often than WRITEs.
That would seem to be a better way to
utilize and configure NICs with 2 LAN ports,
than to complicate your entire system
with dual-port "teaming".
First, I've never seen any open ended PCIe 1x slots. This card won't physically fit in a 1x slot. If its a PCIe 4x card, it will fit in a 4x, 8x, or 16x slot. Just because the dual 16x boards talk about CF/SLI doesn't mean you need to use them both for video cards. You should be able to grab any CF/SLI board and use one of them for it.
Second, I agree that you don't need a dual head card. First reason being that any good modern motherboard already has dual nics. (mine does, and its not even that good.) Second, as already pointed out, you don't really need to move to gigabit. Do so if you have the money, but its not really needed.
Third, its about time that motherboard manufacturers start using ONLY PCIe 16x slots on the motherboard. 1x slots are pretty useless, they accept only 1x cards. 16x slots are the best, as ANY PCIe card should work in it, just at 1x speeds. HELLO, ARE YOU LISTENING? Asus? Anyone?
2 x Gigabit is going to give you around 200MB/s of data transfer, I don't know your server setup but can the disc array/cache in your server consistently deliver 200MB/s of data? If not the dual Gigabit is a bit redundant - go with a single Gigabit link, most users won't see much difference between an internal drive and a network attached disk at 1 GB.
re the 1x Slot - you can open out the end and plug any card into the resulting 'open-ended' 1x slot. But I'm guessing that in a comercial setting wholesale server modification with a dremel is going to frowned on a bit.
If you have a spare PCIe x16 then you can just use that. Essentially PCIe cards work in any PCIe slot they physically fit into (except a few stupid cards like the X700 which has to have 16 lanes and will not work with only 8).