PCIe Interface

[amdusa]

I see that Fit-PC uses 8 PCIe pins for WiFi.
Is it possible to order PC2i with the standard interface that provides all 8+18 pins?
Thanks,
Andy

[yogev_ezra]

Fit-PC2i uses USB interface for WiFi, and not PCIe.
Both PCIe lanes are occupied by 2x Ethernet ports.
The wiring for PCIe slot is there just to simplify PCB design (Fit-PC2 not "i" does have PCIe interface, and the wires are located at the same place)

[amdusa]

Did you mean that the complete PCIe interface (8+18 pins) is available on Fit-PC2?
Please clarify. Thanks.

[yogev_ezra]

Yes, on Fit-PC2. But not on Fit-PC2i.
But if you open your case, it voids your warranty, please note.

[linuxball]

We do already use the fit-PC2 in some of our projects for a while. Some missing features (e.g wake on LAN, analog stereo mic input) kept us from using it for other projects, too.

Now, that fit-PC2i rev. 1.2 with the missing features is available we think about using it instead of fit-PC2.

However, before doing so, I would like to find out the differences between fit-PC2 and fit-PC2i and make sure that the features of the fit-PC2 we utilize are available on fit-PC2i as well. E.g. we use the PCIe interface to run Intel's mini PCIe 4965AGN card with 2 antennas in a 802.11a+n WLAN (a MIMO system operating in the 5 GHz band).

One of my questions regards the mini PCIe socket:

1. The reference guide of for the fir-PC2i from http://www.fit-pc2.com/wiki/index.php?t ... n#fit-PC2i says that the fit-PC2i provides a PCI Express Mini Card Interface (P27) which includes PCIEx1, USB (EHCI), SMB and power supplies and is available if the WiFi option is not used.
   Also, the Changelog of the 22-Apr-2010 BIOS update http://www.fit-pc2.com/wiki/index.php?t ... _ROM_Files says (among others)

   3. Added PCIe boot support

2. Other sources (e.g. http://www.fit-pc.com/web/fit-pc2/specifications) say, that a PCIe interface is not available for the fit-PC2i.

Fit-PC2i uses USB interface for WiFi, and not PCIe.
Both PCIe lanes are occupied by 2x Ethernet ports.
The wiring for PCIe slot is there just to simplify PCB design (Fit-PC2 not "i" does have PCIe interface, and the wires are located at the same place)

From the above I assume that

1. the reference manual is wrong (or not up to date) regarding the PCIe interface and
2. the PCIe interface of the slot cannot be used because the 2nd Ethernet port uses its PCIe lanes
3. a card using the USB 2.0 of the slot can be used

So my questions are:

2. Are my assumptions correct?
3. If 2. is true: Is there any (hardware and/or BIOS) option to use only one ethernet port so that the PCIe interface of the slot can be used again (or do such plans for the future exist)?

I know that one can use USB instead of PCIe (WLAN) or IDE (flash SSD). But we want to avoid USB peripherals as much as possible because:

• We use a Linux RT kernel + latency critical apps and want to avoid additional latency/latency jitter (which USB is prone to exhibit)
• USB can be fairly costly (CPU wise) if it is about higher data rates (compared to PCIe- or IDE-based data transfers)

That is why we are very interested in the availibility of the PCIe interface.

BTW, I'm still wondering what "Added PCIe boot support" in the BIOS change log means. If this does not regard the PCI Express Mini Card Slot is it related to the ethernet ports then (i.e. because booting via LAN did not yet work)?

[irads]

- PCIe is not available on fit-PC2i becuase the two available PCIe lanes are used for dual Ethernet.
- The BIOS shares code with fit-PC2 and CM-iAM where PCIe boot is relevant.
- Other than wake-on-LAN, fit-PC2 rev 1.4 seems to meet your requirements.