RDS Specification and Burstable Performance to what level?

Question

Long time reader, first time poster...  
  
I'm just looking for clarification and hopefully this is a simple one that everyone (except me) knows.  
  
As regards the specification of the burstable RDS instances, it states the vCPU and RAM details. When the instance is performing below a certain baseline, it accrues credits, I understand that.   
  
My question is, to what level of performance? If I am running a t3.2xlarge instance and it has been running at a low level for a while (and therefore has a supply of credits), when there is a spike in requirement, what is the performance level? Is it 100% of the resources for the instance (so in this case 8 vCPU and 32 GB of RAM), or does it go above this - and if so, by how much?  
  
Any advice greatly appreicated.

Accepted Answer

You always get the full amount of RAM for the instance type. As long as you have credits available you also get up to 100% of the vCPU resources for the instance type. The credits accumulate and are spent the same way they are on EC2 (https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/burstable-credits-baseline-concepts.html). For RDS T2 instances you drop to baseline when credits are exhausted.  
  
Since RDS only supports the T3 family in Unlimited Mode, you always have the full performance of the instance available. But be aware that if the average usage over a 24-hour period exceeds baseline then you will be charged for the overage. Again, see the EC2 description on how these instances work. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/burstable-performance-instances-unlimited-mode-concepts.html#how-burstable-performance-instances-unlimited-works  
  
Edited by: HalTemp on Mar 19, 2020 8:29 AM  
  
Edited by: HalTemp on Mar 19, 2020 8:29 AM

Answer

Thanks Hal - that was exactly what I was looking for.

RDS Specification and Burstable Performance to what level?

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