We have a single virtual machine hosted on a VMware ESXi5 host. How best can the resources be allocated to maximize the performance of the VM. Our ESXi5 host has 4 GB RAM with two quad core processors. The VM does have a processor intensive load. ( I understand there is no contention of resources for the processor, I just need to know how much RAM can I reserve for the host machine).
First, I'd ask why you're virtualizing this single server workload versus going with a physical implementation... Is there any plan to host other virtual machines on this physical system?
But given the RAM constraints you have, I would recommend leaving asmall bit of RAM for the hypervisor. 3.5GB-3.75GB of RAM seems right for what you're describing.
On the CPU side, that is going to depend heavily upon what running within the VM. E.g. is it Windows? Linux? Is your application multithreaded?