Wedge4

What version of java are you running, in order to effectively run hexxit, especially to run sphax, you need the 64 bit version, because the texture pack needs access to more than a gigabyte of memory to run, unfortunately a gigabyte is the max you can access with the 32 bit version of java, simply go to the below link and click download to get the 64 bit offline version then go to your technic launcher and click the gear icon in the upper right hand corner, from there just change the ram settings to at least two gigabytes of ram that should solve your problem. let me know if that doesn't work and I'll talk to some friends of mine who know this stuff better than I do.