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Premium Azure SQL DB Performance

Reitse Eskens is moving on up:

The standard tier starts at 125 DTU’s and goes up to 4000. DTU’s are made up from a magic mix of CPU, memory, read iops and write iops. An iop (Input Output oPeration) should be a 4kb (disk cluster size) read or write. 125 DTU translates to 500 Kb/sec up to 32.000 Kb/sec. As we’re used to datapages which are 8Kb in size, you could say these databases are able to pull 62 to 4.000 pages per second from disk. When there are simultaneous writes, you’ll share the performance. At least that’s my interpretation of the IOP. For the DTU part, I’m still struggling to get a good grip on what it exactly is, beyond the magic mix.

It’s also a good idea to compare this to what the Standard tier has to offer. The general data patterns look similar with respect to elbows but the magnitudes are quite different, with Premium P1 starting out around Standard S4 in the test for insertion but more like S3 for selects.