First of all my motherboard is ASRock G41 Express Chipset and i heard that is "Mainstream mobo", and the other thing my ram is only 2GB DDR3. And i'm thinking to upgrade my mobo to "P" series like P43 which is "ENTHUSIAST", or to add + 2GB RAM, so upgrading of these are almost the same price.
Upgrading you MB will do very little to improve performance. Chances are it will have more features, but it won't run your CPU much faster unless it provides more tweaking capabilities and you really want to experiment (based on your question, I'm guessing not). Increasing RAM is the first solution to improving speed because it will reduce the amount of time that the computer is swapping data from RAM to virtual memory on your hard disk.
Also, if you can afford it and you want 4 GB of ram, I'd suggest that you buy a dual channel 2x2GB kit and bag your old RAM. Mixing RAM can be problematic and may actually slow down memory access in some cases.
Also, I believe that all Asrock MBs that have the G41 EXPRESS chipset only support DDR2 ram. If you upgraded the MB you would also have to upgrade all the RAM to DDR3 as well. And if you are planning to upgrade the MB I would broaden my search to other manufacturers. Users don't give the P43 and high rating.
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