i7 920 performing strange please help me to solve this.

Well running multiple apps when 'gaming' isn't a goof thing (notes all the stuff you have running at the same time especially uTorrent which sucks alot of CPU, RAM and Network - for Online gaming). Still goes back to what I said, your maxing out your ancient system, the data being read from the drive caps out because it is SATA II connection / chips, the Core itself caps out because of the old tech, and so on.

Adam: Wha? "I cant play all of them on max but on normal " - What do you mean 'normal', there is no such setting. It is low, medium, high, ultra usually, and the standard (because you spent all this money as compared to say just getting console) is High to Ultra. If you wish to compromise yourself and play at low - medium to get 30fps, your proving the POINT (there is not any lag or stutter...), as the norm is 50FPS or better always.

I do NOT in anyway support; put it on Low settings, play at 640x480, and as long as it is 15fps or better it is 'playing' the game. IMO your just cheating yourself because you don't wish to face the fact the system does not meet the demands placed on it. Further WHY do that at all?? It makes NO sense, when for less then $200 get a PS3/Xbox360 that 'plays those games' and get MUCH better graphics and game play then your outdated PC? You don't need to spend on Titan cards or whatever, because your not looking to get the 'best experiance and playability' out of the game, your criteria is "I play it", well that is what consoles are for. Slap the disk in, turn it on, play it.

By the way my specs:
M17x R2 Alienware 17" Laptop/ OS W7 Pro 64-bit SP1 / CPU Intel Core i7 740QM @ 1.73GHz 71 °C Clarksfield 45nm Technology / RAM 16.0GB Dual-Channel DDR3 @ 660MHz (8-8-8-23) / Monitor Acer GD235HZ (1920x1080@120Hz) / GPU 1536MB NVIDIA GeForce GTX 670M (Dell) 65 °C / Drives HL-DT-ST DVDRWBD CA30N , 232GB Samsung SSD 840 Series (SSD) 38 °C 931GB Seagate ST1000LM014-1EJ164 (SATA) 33 °C 465GB Seagate ST950042 0AS USB Device (USB (SATA)) 34 °C
931GB Western Digital WD Elements 1042 USB Device (USB (SATA)) 32 °C

OP "RIG: i7 920 @ 3.8Ghz, 6gb ddr3 ram tripple channel, 750W PSU OCZ EXTREME, MSI GTX 670 PE,win 8.1 x64 pro"

By the way my specs:
M17x R2 Alienware 17" Laptop/ OS W7 Pro 64-bit SP1 / CPU Intel Core i7 740QM @ 1.73GHz 16.0GB Dual-Channel DDR3 @ 660MHz (8-8-8-23) / Monitor Acer GD235HZ (1920x1080@120Hz) / GPU 1536MB NVIDIA GeForce GTX 670M (Dell)

"You do realize that your CPU and GPU are quite a lot lower performance than the OPs?"
You do realize your completely wrong and apparently are just looking for 'same same' numbers. . I am running the 740QM which is for LAPTOPS, so that means when not gaming I do not need my system running 'full power', which Turbo Boosts (http://en.wikipedia.org/wiki/Turbo_Boost) kicks in when I put demands (gaming) on the machine and cranks the CPU to around 3.5Ghz. Further the op is running a GTX 670 PE, while mine is a 670M, the difference being his is OC able and I am not, and I am running 1.5GB of DDR5, while he is running 2GB of DDR5. So no I am not 'a lot lower performance' I am within margins to make a similar though not EXACT comparison with actual real experience across many titles.

"And you are playing all new games at 50+ fps on high-ultra? With that CPU and GPU?"
If you want to see everything I play, check me on STEAM, under NeroGoth. I am playing currently all three Mass Effect, both Witchers, Skyrim with all DLCs, Dead Island 1 & 2, Walking Dead, Metro 2033 I finished, Batman Arkham City and Asylum, I have the full BF3 package which then garnered me EARLY ACCESS to everyone else onto the BF4 Beta which I played until the last day. Yes I normally on High to Ultra (depending on the Engine of the Game) until I hit BF4, because I too monitored what was 'dragging' on my CPUs, and saw how much ACROSS the CPUs BF4 pulled (nearly 80 several times in my case while newer i7-3xxx CPU scores (http://gamegpu.ru/images/stories/Test_GPU/Action/Battlefield%204%20Alpha/test/bf4%20intel.jpg) shows a significant drop in CPU usage which is to be expected as the performance of each generation of i7 CPU INCREASES, it isn't just the same cores with more 'Clock Speed'. We maxed out on Clock Speed for a while now (see how long over 1Ghz has been around with no more then 4Ghz being the ceiling, and then see how we went from 300Hz to 900Mhz CPUs prior to it).
As I said, for 2013 games and going FORWARD, the older tech (as noted OP is running a SIX YEAR OLD CPU) will continue to be impacted with each new game coming out and simply just getting a better GPU won't matter if the CPU is sitting stuck at over 90% utilization (http://gamegpu.ru/images/stories/Test_GPU/Action/Battlefield%204%20Alpha/test/bf4%20amd.jpg the reason all the Phenom II and FX-4xxx folks filled these forums when BF4 about how crappy thier system works but BF3 they have no problem handling at HIGH (not Ultra) settings before) processing the physics of the front fender of your 'Jeep' will take that M60 shot or will cause the entire Jeep to explode - again not RENDERING the graphics of it happening but calculating the values and code to determine what to send to the GPU to show on the screen.
I will state openly I do NOT support the "crank it down to lowest, 800x600, as long as your over 15FPS your playing the game" mantra ALOT of people state on these forums. If I am spending all this money on a PC, instead of alot cheaper Console, then I should play High-Ultra 50FPS all the time, period. To dump down to just 'play' the game is stupid IMO, because your not getting the 'experiance' advertised that made you want to buy the game. If I just want to PLAY GAMES, then get a freaken console, it is hell lot cheaper (PS3/Xbox360 under $200!!!) and always plays the game exactly as it is advertised. No worries on graphics levels, screen size, etc. to 'make it work'.