Is it posible to connect two motheboards via onboard PCI Express?
My search ended up with PCI express local distance around 20", this should be suficient...

Is it possible to use some kind "cross" cable and SW driver under linux?
For example MB-A(x1)-cable - MB-B(x1)
For scientific research I need more throughput than 1Gb ethernet, x1 will give 250 MB/s in one direction, low latency - and I already have it onboard
any sugestion, links - welcome
please! dont propose USB, ethernet I new all of this...


Other solution (but not desired)is PCI express cable with HIB on each MB (Like One Stop solutions:
onestopsystems.com/new/products/category.asp?tid=3&catID=56 )

How about clustering?

http://openmosix.sourceforge.net/

That's it - cluster required high bandwidth between CPU's
AND If it possible to connect PCI express MB onboard connection with another one and use it as cluster backbone - than you have it (supercomputer under your desk) Just take some cheap MB install Core 2 or x2 CPU's, memory - use another MB as PCI express switch...
Only question remain: did some one tried this or have sufficient knowledge to create connection cable drawing (PIN-to-PIN)?

For example openMOSIX have good use of firewire connection between nodes: tldp.org/HOWTO/openMosix-HOWTO/x907.html
PCI express much better! and it exist even on low cost MB!