For all stock you're in a normal range, though someone will come in here and claim you're CPU bottlenecked and should find a way to push the CPU higher if you want a higher 3Dmark score, or something more in like with a system and dual 260's.  It's not false, just they think leaving a CPU at stock is wrong.
 
The CPU tells the GPUs what to draw, whether game or benchmark, and the GPUs are only limited by the display resolution.  But your whole performance level depends on your preferences, the more you want the faster they need to be. 
 
I remember folks talking about an "n/2" type of enabler in the BIOS to get that 0.5 multi back.  If you have the latest BIOS update to use that CPU, then the option should be in there somewhere, sorry I don't own your board. 
 
Regarding RAM speeds, keep everything linked-and-synced whether you overclock or not, that is your RAM should have the same speed as your Quad-pumped FSB (if at stock, DDR3-1333).  This means if you want your RAM to run 2Ghz, you need to overclock both RAM and CPU since default is generally from 1066-1600.  There are plenty of articles that should be treated as guides and not gospel.  Give them a read through when you're interested, but if you're happy now, that's all that matters.
 
The RAM may have been tested to run at 2000Mhz so it is somewhat gauranteed, but in order for that to happen you must get your CPU to around 500x7.5 = 3750GHz from stock 2.5GHz -- a 60% jump isn't gauranteed and means almost double the heat and power loads.  Clearly you have the right PSU, what about CPU cooler?  If stock, it won't take too much, maybe 3GHz; and depending on your gaming or benchmark preferences, that could be enough. 
  
FWIW, Intel doesn't sell slow CPUs since the vast majority doesn't need them to be faster like the few of us.  If all CPUs were gauranteed stable at higher speeds, Intel would sell them that way with a major premium (but many of us don't generally keep them that long so longivity issues from overclocking don't matter, that doesn't mean there aren't any ).
 
The only disadvantage from leaving our CPUs at stock whether in games or benchmarks have the same effect: As in-game graphics settings are raised, a relatively slower CPU will slow GPUs' to the point where higher-end seems worthless, let alone multi-GPU.