When designing and evaluating performance for networked storage, there is an entire chain of interconnects to consider along the data path. From the interface of the hard drive(s) storing the data to the PCIe connection of the individual client connection’s network interface (and many points along the way), each connection in the path can have its own impact on the ultimate throughput of pushing (or pulling) the bits from point A to point B.
Without going into a complex discussion on performance design (that’s something we can tackle in a future blog series), we simply wanted to offer a few handy tables we at iXsystems use as references internally that layout data rates for the most common storage interfaces and interconnects.
These tables list the maximum effective data rates, in a single data flow direction, for various data interconnect protocols.¹ They can also be used to help quickly convert between Megabytes (or Mebibytes) per second to Gigabits per second (and vice-versa).
Feel free to bookmark this for future reference (or even print it out and tack it to your wall as some of us have). We hope this is helpful. If there is anything else you’d like to see, feel free to post a comment.
¹ Attempts have been made to exclude physical link encoding overheads where appropriate.
Maximum Effective Data Rate (One Direction)
PCI Express 3.0& NVMe |
Mebibytes per second (MiB/s) (1024^2 Bytes) |
Megabytes per second (MB/s) (1000^2 Bytes) |
Gigabits per second (Gb/s) (1000^3 Bits) |
Notes |
x1 |
939 |
985 |
7.9 |
|
x2 |
1,878 |
1,969 |
15.7 |
NVMe M.2 (M+B Key) |
x4 |
3,756 |
3,938 |
31.5 |
NVMe M.2 (M Key) and U.2 |
x8 |
7,512 |
7,877 |
63 |
|
x16 |
15,024 |
15,754 |
126 |
|
Maximum Effective Data Rate (One Direction)
SAS-3(12 Gb/s) |
Mebibytes per second (MiB/s) (1024^2 Bytes) |
Megabytes per second (MB/s) (1000^2 Bytes) |
Gigabits per second (Gb/s) (1000^3 Bits) |
x1 |
1,144 |
1,200 |
9.6 |
x4 |
4,578 |
4,800 |
38.4 |
x8 |
9,152 |
9,600 |
76.8 |
Maximum Effective Data Rate (One Direction)
SAS-2 &SATA 3.0 (6 Gb/s) |
Mebibytes per second (MiB/s) (1024^2 Bytes) |
Megabytes per second (MB/s) (1000^2 Bytes) |
Gigabits per second (Gb/s) (1000^3 Bits) |
x1 |
572 |
600 |
4.8 |
x4 |
2,289 |
2,400 |
19.2 |
x8 |
4,576 |
4,800 |
38.4 |
Maximum Effective Data Rate (One Direction)
Ethernet |
Mebibytes per second (MiB/s) (1024^2 Bytes) |
Megabytes per second (MB/s) (1000^2 Bytes) |
Gigabits per second (Gb/s) (1000^3 Bits) |
1 GbE |
119 |
125 |
1.0 |
10 GbE |
1,192 |
1,250 |
10.0 |
25 GbE |
2,980 |
3,125 |
25.0 |
40 GbE |
4,768 |
5,000 |
40.0 |
100 GbE |
11,920 |
12,499 |
100.0 |
Maximum Effective Data Rate (One Direction)
Fibre Channel |
Mebibytes per second (MiB/s) (1024^2 Bytes) |
Megabytes per second (MB/s) (1000^2 Bytes) |
Gigabits per second (Gb/s) (1000^3 Bits) |
8 Gb |
787 |
825 |
6.6 |
16 Gb |
1,575 |
1,652 |
13.2 |
32 Gb |
3,150 |
3,303 |
26.4 |
And, may your storage always be as fast as your slowest interconnect! 😉
All the best,
The iXsystems Storage Team