Can RAM Bottleneck systems performance

I want to know that could a ram be responsible for reducing systems performance. I had found a similar issue in old system running Core 2 duo cpu. There is 1GB ram installed on the system. They are DDR2 ram operating on low frequency. Now the cpu looks good, and there is a additional 512gpu on the same. But when I run games on that it lags like hell. The same game works on a similar system which has 4GB ram but do not have a gpu. I am bit confused here. Can a ram bottleneck systems performance or there are other more factor responsible for the same. What should I upgrade here if needed.

In my views yes. A memory can bottleneck a system. It does not matter what cpu you are using or how much gpu you had in your system. Unless you do not put a high mhz ram you cannot get benefit from the systems performance. For example a 800 or 1800 Mhz ram is much higher and better than 400Mhz ram. It offer ram more operating frequency to initiate more process within seconds. While the slow ram will not initiate process in a faster rate causing the entire system to get stucked up at a place. So you need a better ram power to initiate a process at faster rate. If you are going for a upgrade a system then it recommend to go for a good hardware for cpu + ram + gpu + motherboard + psu. This are the important factor which define how your system will perform. For example to initiate a game the game specification says that you need minimum 4GB ram and you do not have that much then the game will not respond properly. It is not costly to get some sticks of ram. There are cheaper 2GB stick easily found on web. To get more performance you must also you the most recent driver for your gpu. Another thing, do not run unnecessary process in the background while playing games. It makes your system more resource hungry. And when you are going for a new ram stick there are certain things which you need to take care. First read the specs. Look at the ram clock rate. Which should be more than 800Mhz. Do not go for any lower or else there is no use of purchasing the same.

In some cases when there is extreme fall in the performance then there are chances that the ram is faulty. You can use bootable disc like UBCD to find out the issue with ram. This disc has a memory diagnostic tool which can help to detect the rams health.