Yes, a RAM bottleneck can affect a GPU's performance.
Yes, a RAM bottleneck can affect a GPU's performance.
You might want more RAM if your system is slow or struggles with multitasking.
I believe 4GB is the minimum needed by NVIDIA for the 10-series. There’s not much left for gaming.
Consider replacing the 1GB stick with a 2GB one. Switching to DDR3 1333 makes it sensible to upgrade later to DDR3 1866 or 2400. For example, with a 4790K running at 51GB/sec, moving to a 3200 MHz model would be beneficial compared to your current 1600 kit at 25.6GB/sec.
Because 64-bit Windows is common, the system runs smoothly on most games. With 4GB of RAM available, I’m fine for most titles—though I’d recommend 10GB or more if you’re playing Fallout 4.