Hi,
The motherboard has a LGA1156 CPU socket and the chipset is a H57 Express so based on these parameters you can upgrade the CPU to an i7 870 (known to work with your motherboard) with normal CPU fan cooling
The ram can also be upgraded to 8GB i.e. 4 x 2GB DDR3 PC3-12800 modules.
Another way to increase performance is to replace the HDD with an sata SSD
Other than that given the age of the motherboard it wouldn’t be worth investing too much more into improving performance due to the limitations imposed by the chipset and the motherboard which were designed 10+ years ago - a lifetime in computer technology.
Here’s the service manual which may be of some help.
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