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IOPS Estimation for EMC VNX-F5000

Written on:May 8, 2015
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In this article, we estimate the performance of the new Flash storage system EMC VNX-F5000 for different workload profiles, as well as other parameters of IOPS per GHz, IOPS per GB.

All the performed calculations are based on the methodology described in the article «Methodology of IOPS Estimation».

Let’s gather all necessary information needed to a calculation.

  • The frequency of processor cores – 1,8 GHz.
  • The number of cores on the one controller – 4.
  • The sum frequency calculation – 4×1,8 GHz = 7,2 GHz.
  • At this stage we can get a rough upper estimation of the IOPS for one controller. To do this, it is necessary to use the relation between the number of IOPS and sum frequency of the controller. This value is specified in the methodology (10000 IOPS / GHz). Let’s multiply 7,2 GHz x 10000 IOPS / GHz, we obtain a rough estimation 72000 IOPS per controller. Thus, the performance of a pair of controllers is equal to 144000 IOPS. We can use these rough estimates for self-examination.
  • We take information about the configuration of RAID groups in the «View on new EMC VNX-F»:
    • RAID 5 SSD are used in the configuration 8+1.
  • Max 1,6TB data disk drive quantity for the VNX-F5000 is 36 (4 Raid Groups per 9 drives).
  • 4 drives are used for OS and minimum 2 drives for hotspare.

Now we have all necessary information for our calculations.

The estimation for max IOPS (Cache Read Miss)

Let’s set the basic values for the estimation:

  • Read operations – 99%.
  • The configuration for MLC drives – RAID5 8+1.
  • The quantity of groups – 4.

As a result we got such a calculation:

05262015_VNX_F5000_IOPS_R99

The graphic representation results of calculation:

05262015_VNX_F5000_IOPS_R99_graph

Total:

Max IOPS is 135922.
Max IOPS for one controller is 67961.
The ratio IOPS/GHz is 9439.
The ratio IOPS/GB is 2,717.

Real Flash storage capacity is about 49 TB.

Let’s compare this result with a rough estimation, which we did in the beginning of this article. Then we got 72000 IOPS for one controller. The difference with the new result is about 6%.

The IOPS estimation for DB like workload (Cache Read Miss)

Initial parameters are the same, but the percentage of read operations is different. Typical ratio between read and write operations is equal to 70/30 for databases (OLTP workload).

05262015_VNX_F5000_IOPS_R70

The graphic representation results of calculation:

05262015_VNX_F5000_IOPS_R70_graph

Total:

Max IOPS (DB like) is 73684.
Max IOPS for one controller (DB like) is 36842.
The ratio IOPS per GHz is about 5117.
The ratio IOPS per GB is 1,473.

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