Legend of Grimrock game not utilizing entire cpu performance

Hello friends, I have observed some low performance of my system, such that when I am playing the Legend of Grimrock game, when I have started playing this game then I was getting good fps but all of sudden getting less fps. I have checked task manager then I found that CPU usage is more but getting low FPS when playing it, does not know what the problem is? I have also seen that there are couple of people who are facing this same problem but there is no proper solution for it, so I would like to know that this problem with game or with my system, please help me out with it. Thank you.

If you check out the system requirement for this game then you should have Intel Core 2 Duo E4400 2.0GHz or AMD Athlon 64 X2 Dual Core 4600+ processor along with Nvidia GeForce 7600 GT 256MB or AMD Radeon HD 6450 graphics card, with minimum 2 GB RAM and should have Windows XP 32-bit operating system. But that it not at all enough for game, if you like to have good performance then I would recommended to use Intel Core 2 Quad Q6400 2.13GHz or AMD Phenom 9650 Quad-Core with Nvidia GeForce 8800 GS or AMD Radeon HD 2900 Pro graphics and have 4 GB RAM. When you will be having those system requirements then it will be not a problem for you. There is patch for this game, which has fixed the bugs in game, so I would suggest having a look on following link and check out that it is solving your problem or not.

Legend of Grimrock Patch 1.1.4

I would like to tell that Legend of Grimrock is a high end graphics card game which is being designed to consume specific percent of the processor, if it is consuming more than that then you will be able to getting lagging problem while playing it, even there are some game which are being designed to played on some processors, if you are using a lower one then it is for sure it will be consuming more of it. When you are playing this game then better make sure that there is no other application running in background which is using more CPU resources then close it and start playing it. When you have closed those applications then check that CPU usage is still the same or not. If then also it same, so I would suggest you to do some changes in your graphics cards settings. Whenever you are purchasing any game then it is recommended to use particular system requirement for game and also do some changes to get better output.