Back in my old *nix classes we learned to always add double the swap as ram installed. Maybe adding more swap space would help increase the performance.
swap is virtual memory that utilizes hard drive space. Id set the swap to 8gb... In my humble opinion, I would imagine it will help.
It's as old as the hills that advice. It stems back to when machines had in the order of 256Mb of RAM. With the 32bit machines reaching to 2Gb it became defunct. You can't have more than 4Gb of total RAM and swap on 32bit. You can create it, but it won't be used.
Beyond that 64bit machines are now running 4Gb as a minimum usually and 8Gb of swap, if you ever had to use it would ... well... you could get a cup of coffee while it churns you HDD for ages.
Swap only prevents OOM situations by shifting the last accessed memory pages to disk, leaving room for current pages. The disc is many orders of magnitude slower than memory. Memory access is around 5-10ns where as HDD access is usually around 10-50us. SDD faster, but don't use SDD for swap!
And, to be a pedant, virtual memory is a term often used incorrectly. Virtual memory refers to the total address space of the computer. 4Gbyte on 32bit. Many terrabytes on 64bit. A process has access to that completely memory address space. The OS then maps different processes to pages which exist either in pyshical memory, disc "swap" or other memory paging storage, which can even be network attached memory. But it's pedantry. We knew what you meant.
For swap space size these days I give it a token 2Gb. I have 16Gb RAM, if I start seeing swap being used, something has gone horribly wrong.
For systems using a lot of swap a performance increase (though temporary) can be achieved by closing most of your applications, removing the swap and adding it back on. This forces a completely flush of swap back to main memory.
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