It is really frustrating to figure out if you have enough speed on your cpu for a game. It used to be if you knew the frequency of a cpu you knew it's speed. Maybe that is still true, I don't know anymore. I look at cpu charts and they say core 2 duo is faster than other chips. So I bought a core 2 duo 6300, the most I could afford. Now I found out Cryses will not play on my system because of my frequency speed. Is it better to buy a single core with higher speed or multicore's with lower speed?

Crysis will definitely play on your system... Physics and all CPU bound options on high most likely with no major slowdowns. You got a great little chip there buddy! Single cores are a thing of the past, will play most games out there, but don't expect any miracles. Your chip can handle all games in the present and foreseeable future without any problems, however if you want faster FPS you should consider OC'ing it.

Hmm? The frequency speed is deceiving, especially after Intel released their Pentium 4 processors, which, empasizes huge frequencies while sacrificing performance itself.
 
If you would look at that CPU charts, you might be suprised, if a Core2Duo at 2Ghz is faster than a Pentium 4 at 3.0Ghz.

 
According to who?  The 6300 should be enough to play Crysis.  (I'd rather have the 6300 then the P4 3GHz.)  The only question at this point is what video card do you have?  The higher the resolution you want to play at, the bigger the video card you need.  If you are worried about how well you can play Crysis, post your system specs and somebody should be able to tell you how well it will run.

Hold on now, you 6300 is a great little chip and should play crysis with ease. You see the core 2 which you have has a different architecture than the p4's allowing it to be more efficient clock for clock. So for example using "fake" numbers here lets say ur core 2 is 50% faster clock for clock than a p4 so ur 2.0ghz core 2 would be like a 4.0ghz p4. Now keep in mine these aren't real figures however it would be simmilar to this. Please some one correct me if I'm wrong.  

Fortunately the listed system requirements for newer games are less commonly listing speed requirements, but specific CPU models. Your CPU is fine, but an overclock to 2.4GHz would make a good bit of difference methinks.

My biggest question is what his GPU is? Of coarse if he has enough memory too would help troubleshoot better. Heck, I can even play Crysis on my laptop, which only had 1 gig of DDR2 and a ATI x1400 GPU. Yes I didn't have everything turned up, but I could play pretty well with okay settings.

CPU is the most important thing in crysis. If you don't run something decent then it doesn't matter what you got in your rig. Once you deal with the CPU, you run into problems with everything else.

Definitely get a DUAL core.... Even the fastest P4 which is 3.8 ghz is no match for the speed of the slowest dual core  which is E2160 (in the market now...)
 
Dude.. enjoy playing

Er... the OP said he got an E6300.

Yeah. Plus the 6300 OC's GREAT!!
 
Squeeze like 400 extra mhz out EASY
 
Don't be down buddeh.

Yeah that Cpu should be fine but the real question is what you're graphics card is

 
This is the one thing that gets confusing. A lot of games still go based off of the old P4 standard with some moving to the newer C2D and Athalon X2 arena. The CPUs you see are higher frequency(so 2.4GHz P4 for instance) But have less IPC(instructions per clock) Than your C2D E6300. What that does is give your E6300 better performance.
 
Now it can play Crysis. But you wont have all the goodies and such unless you have one hell of a GPU setup, say Tri SLI 8800 Ultras or CFX 3870X2's.

I have a lesser processor than you have, and Crysis works on my machine.
 
As long as you have a halfway decent video card you should be able to play at least on low settings.

Yeap ur right because of the change in the architecture any thing before the Dual Core series like E2160 were using different ways to present their performance so is valid for me that if u see 4 example a processor Dual Core and Core 2 Duos or Quads just simple multiply the speed by 2 ... 1.6 Ghz x 2  = 3.2 Ghz ... the minimum speed that u will really receive is that and sometimes faster because of the multithread optimization so an E2140 1.6Ghz is similar to the old Pentium D 935 of  3.2 GHz ... here a chart that i hardly doubt u will find in the internet is from Intel itself ...lol

http://img205.imageshack.us/my.php?image=intelkm7.jpg

Otherthing i have an e2180 of 2.0Ghz running up to 2.81 Ghz in a g31 motherboard just make sure to get a P35 motherboard like Gigabyte p35-s3l or something but with that chipset and u will get 3.2 Ghz with easy...