It is normal... i have game who have reach more that 10 gb ( not with the win OS who is limited to 2-3gb for win32 and 4gb for win64 using wow64 who emulate a 32 bits enviroment for sins)

Reason is simple... all the mesh, texture, entity file are loaded at the start... add all the data needed for all object on your map... Huge multistar map ask a lot of ram...

Reduce your graphic setting will spare some memory since sins will use lower quality texture who take lower ram...

Until Stardock change the engine to allow the use of "onlyLoadOnDemand TRUE" on any file, sins will always need a lot of ram... a 64 bits of the sins engine will be great too since i have enough ram (16 gb )... multicore support will be good too....

Boy, it is Sins, first game in his genre... i am waiting to try SinsII and the new engine in a few year...

Crysis need high end graphics card because of the quality of render... but no one map show several thousand of mesh in the same time or use so much particule effect... without speaking about the huge internal calculation... imagine a map with 100 planet... planet fully build with one or two trade port... now, convert this in the number of cargo ship running the galaxy... it become fast a huge amount ship... playing with 10 player... combine all the fleet together... all this work is made by the processor and need a lot of ram...

Positive thing is that sins can run on computer with some older graphic card... and more low end processor... only RAM is a problem i some case... Sins is a strategy game, the 3D graphics is a bonus... In Crysis, the game is enough simple but everything is based on very high graphics... some function are only unlock with dx10 !!!

A other thing... in Sins, everything is loaded at the start, it is needed for build the full Galaxy where you play... Now, Crysis is working with episodes... Imagine the RAM use of Crysis if all the episodes ( scenes ) was loaded in the same time...