Slow API for Extracting small piece of data from Performance Manager

I was trying to extract the average CPU usage of multiple VMs using this API, and used a similiar approach as in one of the sample codes. I have been extracting this data by doing this the following(pseudo-code):-
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containerView = content.viewManager.CreateContainerView(container,viewType,recursive)
counterIDs = [0,1] //IDs for CPU usage
metricIDs = [vim.PerformanceManager.MetricId(counterId=c, instance="*") for c in counterIDs]
//Build a spec
spec = vim.PerformanceManager.QuerySpec(maxSample=1,entity=child,metricId=metricIDs,intervalId=20)
//Get results by querying PerfManager
result = perfManager.QueryStats(querySpec=[spec])
// Parse result to get the data

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It seems that the API seems to send multiple set packets of information to and fro thereby making this extraction quite slow. Is there a faster way to extract just this small piece of information of CPU usage instead of exchanaging large packets of data to and fro?

Start by reviewing the PerformanceManager QueryStats call and the sample approach shown in the issue, including CreateContainerView and QuerySpec. Determine whether the API supports a narrower CPU-usage request or a more efficient retrieval path, then verify the result against the reported packet volume and extraction speed.