How estimate fabric capacity

[dacopan2]

Hello friends, I need help with estimate fabric Capacity plans.
I am currently using the trial version and have estimated a consumption of approximately 3M CU(s) daily, distributed as follows: 1M CU(s) in a specific hour and the rest spread throughout the day.

I would like to understand:

If I choose the F4 plan, how can I determine if it will meet my needs?
What happens if I exceed the F4 plan's capacity?

For example, we plan to load data daily at 4 a.m., and this load should take no more than 20 minutes. Based on my estimation, this load would consume 1M CU(s).

Would an F4 plan cover this usage?
What is the formula to calculate whether a specific plan can handle a given workload?

I saw in the documentation that an F4 plan corresponds to 4CU or 120 CU(s) in 30-second intervals, but in the trial metrics dashboard, I observe values of 1M CU(s). How do these values correlate? to make a fomrula to determine correct CU capacity plan

[v-tsaipranay]

Hi @dacopan2 ,

Thank you for reaching out to Microsoft community forum regarding the F4 plan and your capacity needs.

As we known that F4 plan provides 4 CUs per interval, equalling 120 CUs per minute Over 20 minutes, it delivers 4,800 CUs. As mentioned, you need 1M CUs in 20 minutes for your 4 a.m. load. The F4 plan cannot meet this demand, as it only provides 4,800 CUs.

If your workload exceeds the F4 plan’s capacity, it can result in throttling (delays in processing) or task rejection, meaning some of your tasks may not complete within the expected timeframe.

To calculate whether a plan can handle your load, use the following formula:

                                                   Total CUs required=CUs per interval×Number of intervals required

In your case:

• For 20 minutes at 1M CUs, you require 1M CUs. F4 plan provides 120 CUs per minute and 4,800 CUs in 20 minutes, which is insufficient.

As you mentioned In your trial dashboard, 1M CUs might be your daily consumption. The F4 plan provides 14,400 CUs per hour, but for spikes like 1M CUs in 20 minutes, you'll need a higher-tier plan like F64 or F128 to meet your 1M CUs in 20 minutes.

I hope my suggestions give you good ideas, if you have any more questions, please feel free to reachout.

If this post helps, then please give us Kudos and consider Accept it as a solution to help the other members find it more quickly.

Thank you.

[dacopan2]

Hello, thank you for your detailed response! However, you mention 4 CUs per interval, equaling 120 CUs per minute, but on the website, it states that 4 CU equals 120 in a 30-second interval.

Does this differ from what you explained about 120 CUs per minute? Or am I misunderstanding your explanation?

[v-tsaipranay · Accepted solution]

Hello @dacopan2 
Hope you are doing good.

I apologize for the mistake in my previous message. The correct interval is 30 seconds, not one minute as I originally mentioned. This was a typing error. We appreciate your understanding from the document.

If this post helps, then please give us 'Kudos' and consider 'Accept it as a solution' to help the other members find it more quickly.

Thank you, have a great day.