Difference between Expected bandwidth of Azure VM and that showing in Portal

Question

According to the documentation - The Max bandwidth for Standard_D4s_v3 is 2000 Mbps

in Azure portal, VM Monitoring blade, the total network out shows :

From what i understand - this data in portal is shown at 1 Minute granularity

42.6 MiB is Per Minute = 42.6 /60 = 0.71 MiBps

0.71 MiBps = 5.95 Mbps

But the Max bandwidth is 2000 Mbps

How do i convert 2000 Mbps so that i know the Expected bandwidth in MiBps or GiBps?

Can i get a clarity on how this calculation is done

Answer 1

Hi,

Basically the VMs in Azure share the bandwidth among other VMs in the stack as they are hosted on the shared hardward so the estimated and expected bandwidth calculations will always differ in real world scenarios.

Also if there are multiple NICs on the server it will impact the bandwidth or the output from the VM and might skew the bandwidth calculations, on the bandwidth and detailed information cited here in this article.

I will request you to setup the Network throughput tool to calculate the bandwidth and great tool to have on the network to periodically calculate the performance.

Hope this helps.
JS

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Answer 2

@Vootukooru, Nishanth
Jimmy is correct when talking about the network and expected bandwidth, just adding some additional information. 2000 megabits per second would translate to 250 megabytes per second. Sharing some additional resources around testing and network performance expectations:

Virtual machine network bandwidth
Bandwidth/Throughput testing

When doing a simple test through Speedtest on my Standard_D4s_v3 Windows VM you can see I was reaching near the throughput limit.

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Answer 3

My Requirement is to calculate the Network Utilization %

To rightsize a machine, Azure considers Network Utilization %.. which i am not able to find... in the metrics.. so it needs to be calculated.. i wanted to know what is the basis behind this calculation...

Answer 4

@Vootukooru, Nishanth
Thanks for the additional context. I see you are referring to the Azure Advisor recommendations. These calculations are performed automatically, and the recommendations are presented to you in the Cost tab. If a VM meets this criteria you can find it here, you will also see the utilization information under additional details.

If you have a need to calculate this by yourself you can do the math for 7 days and utilize metrics to verify. You can look at the full 7 days and set the granularity to 1 day.

Example of 100% utilization for Standard_D4s_v3:
2000 Mbps x 60 seconds x 60 minutes x 24 hours x 7 days = 1,209,600,000 megabits = 1,209,600 gigabytes

40% of this is 483,840 GB.

Hope this helps. Let me know if you still have questions.

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Answer 5

I don't think this answer's my question.

I want per hour Network Utilization %

This is what i did in my calculation:

• Convert MaxNetworkBandwidth from Mbps to MiBps = MaxNetworkBandwidth / 8.388608
• Take Maximum_NetworkOutTotal
• And TotalNetworkInOut / MaxNetworkBandwidth = MaxNetworkThroughput% at each hour

But the problem is :

If you see in my screenshot in 1st message,

At a specific hour my MaxNetworkout was

• MaxNetworkBandwidth for Standard_d4s_v3 = 2000 Mbps = 2000/8.388608 = 238MiBps
• But if you see the MAXIMUM limit in the Graph i shared in the 1st message it only has 47.7 MiB - Shouldn't it be 238MiBps which is the given Config for that Instance Type ?