FREE · NETWORK & IT INFRASTRUCTURE
Storage IOPS Calculator.
Find how many drives a workload needs from its IOPS, read/write mix and RAID write penalty, and compare HDDs, SATA SSDs and NVMe.
Use sustained mixed-workload figures, not the peak 4K read number from a datasheet.
- Back-end IOPS (after write penalty)
- 26,000
- Drives for IOPS
- 186
- Drives for capacity
- 17
- Throughput at this I/O size
- 163.8 MB/s
- Usable capacity of the array
- 223.2 TB
- Functional IOPS of the array
- 20,031
Same workload on other drives
| Drive type | Drives for IOPS |
|---|---|
| 7,200 rpm HDD | 325 |
| 10,000 rpm SAS HDD | 186 |
| 15,000 rpm SAS HDD | 137 |
| SATA SSD (sustained mixed) | 2 |
| NVMe SSD, data-centre (sustained mixed) | 2 |
- Functional IOPS = raw IOPS × read % + raw IOPS × write % ÷ write penalty. Controller caches and SSD tiers can hide part of the penalty.
- Replace the per-drive IOPS with figures measured with fio or the vendor’s steady-state numbers for your block size.
How to use Storage IOPS Calculator
Enter the workload IOPS, read share, I/O size and capacity, then pick the RAID level and drive type.
How it works
Back-end IOPS = workload × (read % + write % × write penalty). Drives = back-end IOPS ÷ IOPS per drive, then at least enough for the capacity.
Example
20,000 IOPS at 70 % reads on RAID 10 with 10k SAS drives needs 186 drives; NVMe needs 2.
Questions about Storage IOPS Calculator
Is Storage IOPS Calculator free, and do I need an account?
Yes. This tool is free to use in your browser without an account. Processing takes place on your device.
What are the limits and what should I check?
Per-drive IOPS are conservative sustained values; use measured or vendor steady-state figures. Controller and SSD caches are not modelled. Everything is calculated in your browser; nothing is sent or probed on the network. Review the result before using it in your work.
Is my input sent to a server?
Your input is processed in your browser and is not uploaded by this tool. Files and pasted text are cleared when the page is refreshed. Normal website requests are still required to load the page and its libraries. Read the privacy explanation.