Pfsense Router Specification

Networking
1

Here is the specification list:

  • CPU: Intel PDC E5700
  • RAM: 4 GB DDR3
  • Network Cards:
    1 Onboard
    2 Realtek 100Mbit (which I know works with pfSense)
    3 Intel 8492MT Pro dual network adapter*
  • Storage: 32 GB USB stick

Now, my question is will the * marked "Intel 8492MT Pro dual network adapter" work with pfsense and will my PDC E5700 able to handle gigabit speed file transfer?

And should I consider buying a Xeon X5355 from ebay for 5$?

2

IDK about the network adapter. Try it! Intel adapters tend to have good compatibility so it will probably be fine.

That CPU: 

Launch Date
Q3-10
Lithography
45 nm
Number of Cores
2
Processor Base Frequency
3.00 GHz
Intel® AES New Instructions
No

From http://ark.intel.com/products/42801/Intel-Pentium-Processor-E5700-2M-Cache-3_00-GHz-800-MHz-FSB

That processor is overkill for your setup. It could probably break 45FPS on Shadow of Mordor actually with a 1050Ti. Anyway, it might start to get a load above 10% if you do a lot of VPNs, like 10+, due to the not having the AES accel instruction set hardware enabled. <5 should be fine. That is plenty for normal GB-transfers.

I don't think that Xeon supports AES instruction accel since it is even older than the Pentium so is not really worth purchasing for VPNs or anything really. Only get it if you plan to do a lot of VPNs.

3

All of it looks good except the CPU.

Bear in mind when PfSense 2.5 releases it will require Hardware Based AES-NI.
Currently it is done through software, but for many reasons for and against it is being removed.

How does this apply to that CPU? It doesn't have AES-NI. You need to look for a more modern chip if you plan to work with PfSense 2.5 once it releases (next year I believe).

Source: https://www.netgate.com/blog/pfsense-2-5-and-aes-ni.html