AWS: Save up to 19.2% on t* instances

Despite what AWS may say, the burstable CPUs are a workhorse for so many smaller workloads – the long tail of deployments in the cloud.

Yesterday saw the announcement of the AMD based T3a instance family as generally available in many regions. Memory and core-count matches the previous T3 and T2 instance families of the same size, which makes comparisons rather easy.

Below are prices as shown today (25/Apr/2019) for Sydney ap-southeast-2:

Sizet2 US$t3 US$t3a US$Diff t3a-t3%Diff t3a-t2%
nano.0073.0066.0059.000710.6.001419.2
micro.0146.0132.0118.001410.6.002819.2
small.0292.0264.0236.002810.6.005619.2
medium.0584.0528.0472.005610.6.011219.2
large.1168.1056.0944.011210.6.022419.2
xlarge.2336.2112.1888.022410.6.044819.2
2xlarge.4672.4224.3776.044810.6.089619.2

As you can see, the savings of moving from one older family to the next is consistent across the sizes: 10.6% saving for the minor t3 to t3a equivalent, but a larger 19.2% if you’re still back on t2.

It’s worth looking at any pending Reservations you currently have for older families, and not jumping to this prematurely – you may end up paying twice.

Talking of which, Reservations are available for t3a as well. Looking at the Sydney price for a nano, it drops from the 5.6c/hr to 4c/hr; across the fleet, discounts on reserved versus on-demand for the t3a are up to 63%

For those who don’t reserve – because you’re not ready to commit, perhaps? – then the simple change of family is an easy and low-risk way of reaping some savings. For example, a fleet of 100 small instances for a month on t2 swapped to t3a would reap a saving of US$2,172.48 – US$1,755.84 = US$416.64/month, or just shy of US$5,000 a year (AU$7,000).

YMMV, test your workload – and Availability Zones – for support of the t3a.

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