Hello,

We are currently evaluating EMC ScaleIO 2.x on Microsoft Windows Server 2012 R2.

We are testing in a 3-node cluster, each node has 4x Samsung PM863 512GB SSD. The nodes have the latest Intel XEON CPU and 64GB of internal DDR4 memory (quad-channel).

Each node has 5x Intel 1Gbit network connection (5Gbit total) which are used for both SDS and SDC, we are using ScaleIO load-balancing.

(I know, networking could be better like 10 Gbit, but this should work fine for a small environment I guess. We are happy with the sequential performance like this, we don't need more)

When doing performance measures using different tools (CrystalDiskMark / ASSD Benchmark / IOMeter) we are seeing extremely slow random 4k reads and writes at queue depth 1, while the rest seems fine.

Here are our benchmark results:

Sequential read (qd 32) : 788 MB/s

Sequential write (qd 32) : 560,9 MB/s

Sequential read (qd 1) : 217,9 MB/s

Sequential write (qd 1) : 220,2 MB/s

Random read (qd 32) : 70.000 IOPS

Random write (qd 32) : 45.000 IOPS

Random read (qd 1) : 190 IOPS

Random write (qd 1) : 1500 IOPS

To us the random 4k IO with QD1 seems extremely slow, while random performance at queue depth 32 is fine (peaks at 80k IOPS which seems impressive to me). 190 IOPS however is what one would expect from an old harddisk using mechanical components!

When testing the drives standalone the performance seems fine, but when testing a ScaleIO volume on a Windows node we are seeing this.

We already tried the following:

- Disable all power saving features

- Change the performance profile in ScaleIO for both SDS and SDC (note: when the performance profiles are set to high, performance will be actually lower, weird!)

- Disable a node

Any suggestions would be more then welcome! Thanks in advance and best regards,

Paul