The formula is:

max_number = min (int((Total Memory – 4G)/1.3G) , Number of cpu virtual core * 2, max_number_hard_limit)

Therefore, the maximum sandbox instances that can be run on the current hardware will be limited by 3 factors:

• (Total Memory – 4G)/1.3G
• Number of cpu core * 2
• max_number_hard_limit (60 VAs)

For example:

For a Dell R720 with dual 6 core E5-2630v2 CPU and 48GB memory, the memory will limit this hardware to only have int((48-4)/1.3)==33 sandboxes.

Since the E5-2630v2 CPU supports hyperthread, the dual CPU can only provide 24 VCPUs in total. This means the CPU spec will limit this hardware spec to only support a maximum of 48 sandbox instances.

The "max_number_hard_limit" is hardcoded. This will limit a single server to only run a maximum of 60 sandbox instances.

The min() surrounding the above factors will get the minimum number of 3 factors. Thus, the hardware can only support 33 sandbox instances.