Say what?!?! Standard SSD disks? And we thought that Standard = HDD and Premium = SSD! But that’s no longer the case.
In the coming world of Azure (we’re not there yet), Premium will be just that, but Standard will be normal deployments of either HDD or SSD. How do the three tiers of managed disks break down?
- Premium: For when you need the highest IOPS, throughput and lowest latency.
- Standard SSD: For production workloads when you need predictable IOPS performance (500 per disk) with lower latency than HDD.
- Standard HDD: Test and archive storage in VMs, with IOPS listed as up to 500 IOPS – spinning disks are based on serial access and bursts of activity lead to access queues and lower performance levels.
Let’s set expectations: Standard SSD is in very limited preview today. Only North Europe (Dublin) is supported today, with several more regions coming online internationally by mid-June:
- France Central
- East US 2
- Central US
- Canada Central
- East Asia
- Korea South
- Australia East
There is no Azure Portal support today. If you want to deploy Standard SSD disks, you must do it using ARM templates:
- apiVersion for Microsoft.Compute/virtualMachines must be set as “2018-04-01” (or later)
- storageAccountType as “StandardSSD_LRS”
Won’t SSD be too expensive compared to HDD? That was my first thought. But check out the RRP pricing (North Europe in Euros). The per-GB pricing for Standard HDD is:
But the per-GB pricing for Standard SSD disks is:
The per-GB cost of Standard SSD is LOWER than that of Standard HDD. How could that be? Electricity is a huge cost in data centers, and disk arrays eat up a lot of power. SSD is way more efficient, the cost of SSD has been falling, and Microsoft eats the commodity storage hardware dog food.
If you read the pricing small print, you will notice that the micro-cost of storage transactions in Standard SSD is €0.000844 per 10,000 transactions, double the Standard HDD cost of €0.000422 per 10,000 transactions but that’s one of those costs that’s tucked away at the bottom of the bill that few ever notice because it’s tiny.
Standard SSD, managed disks only, is LRS only, as with other managed disks. They also come with the usual 99.999% availability, and Microsoft’s claimed ZERO percent annualized failure rate.
I’m looking forward to the day that Standard SSD is GA and I can start telling customers to switch over to it as their normal disk, when Premium isn’t required.
Very interesting read! At first I saw the announcement, and saw the specs of both Managed HDDs and SSDs were the same, so I was a bit underwhelmed. But the latency is lower and a lot more consistent, so that makes it a bit more useful.
Regarding the fine print though: at 2592000 seconds in a month, charged per 10000 transactions, and 500 IO/s, theoretically this could end up being a maximum of 109 euro surcharge. This would of course rarely be hit, but if you calculate the numbers through, it’s about €0.219 for every I/O you use every second of the month. At 50 IOPS continuously, you’d have about €10,94 per month extra. Premium disks do not have this transactional cost.
Azure backup vault still not supported by “Standard SSD” (Sept 18/2018)
=> “The storage type is not supported by Azure backup”