In my experience so far with Azure the biggest bottleneck seems to be Storage performance. I did a few tests with Crystal Disk Mark and as you can see below the performance is very poor. Especially write speed on "Premium" storage is catastrophic! Me personal laptop SSD it's 20 times better!

Is this the expected performance or am I missing something obvious?

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  • is it like hybrid solution? or everything is cloud over NETWORK which in this place could be a bottle neck. – Michal Jun 15 '16 at 10:59

There are some limits in Azure Premium Storage that you should consider to get optimal performance. In particular as you can see here there are IOPS and Throughput limits per premium disk. And they are different for different disk types. Moreover there are some limits per VM Size. So for the best result you should choose right VM Size, disk type and number of such disks.

I guess in your example you've met IOPS per disk limit that for P10 disk is 500. With 4K read/write block size operations you can achieve 500 * 4K = 2 MB/s throughput.

Try to do the same test with P30 disk for example. You can add it and choose disk type on Azure Portal.

  • Thanx Alexander...this make sens now – Albert Jun 15 '16 at 15:42
  • You are welcome. Please mark your question answered for a future reference, if that was helpful. – Alexander Shapoval Jun 16 '16 at 8:38

Recommended disk format size in Azure for any type of disk is 64K not 4K. This is due to the network nature of how storage is delivered to the VM.

Try your tests with 64K.

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