64bit Dual Opteron... Can we use all we have?

For the past year my team and i have been developing an MMORPG useing the torque engine, a dual 64bit opteron server fell into our laps for about $900 (going out of buiness auction) however i have looked through the TGE code and it appears that troque isnt thread safe... we would also like to run linux on the server so the only things running are the kernel the neccicitys for torque deticated and mysql so i have 2 questions

Can we use all 64bits of power, if so how do we do it?

Secondly can i get troque to run with multithreaded support? (not as large an issue as a second plan we can just split the zones up between the 2 (matter of fact that might be a better idea anyway))

Thanks for you help in advance