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Samsung 950 Pro M.2 PCIe Gen 3x4 NVMe SSD RAID 0 Report

By: Jon Coulter | RAID in Storage | Posted: Feb 17, 2016 2:15 pm

Futuremark PCMark 8 Extended


Heavy Workload Model


PCMark 8's consistency test simulates an extended duration heavy workload environment. PCMark 8 has built-in, command line executed storage testing. The PCMark 8 Consistency test measures the performance consistency and the degradation tendency of a storage system.


The Storage test workloads are repeated. Between each repetition, the storage system is bombarded with a usage that causes degraded drive performance. In the first part of the test, the cycle continues until a steady degraded level of performance has been reached. (Steady State)


In the second part, the recovery of the system is tested by allowing the system to idle and measuring the performance after 5-minute long intervals. (Internal drive maintenance: Garbage Collection (GC)) The test reports the performance level at the start, the degraded steady-state, and the recovered state, as well as the number of iterations required to reach the degraded state and the recovered state.


We feel Futuremark's Consistency Test is the best test ever devised to show the true performance of solid state storage in an extended duration heavy workload environment. This test takes on average 13 to 17 hours to complete and writes somewhere between 450GB and 14,000GB of test data depending on the drive. If you want to know what an SSD's steady state performance is going to look like during a heavy workload, this test will show you.


Here's a breakdown of Futuremark's Consistency Test:


Precondition phase:


1. Write to the drive sequentially through up to the reported capacity with random data.

2. Write the drive through a second time (to take care of overprovisioning).


Degradation phase:


1. Run writes of random size between 8*512 and 2048*512 bytes on random offsets for 10 minutes.

2. Run performance test (one pass only).

3. Repeat 1 and 2 for 8 times, and on each pass increase the duration of random writes by 5 minutes.


Steady state phase:


1. Run writes of random size between 8*512 and 2048*512 bytes on random offsets for 50 minutes.

2. Run performance test (one pass only).

3. Repeat 1 and 2 for 5 times.


Recovery phase:


1. Idle for 5 minutes.

2. Run performance test (one pass only).

3. Repeat 1 and 2 for 5 times.


Storage Bandwidth


PCMark 8's Consistency test provides a ton of data output that we use to judge a drive's performance.




We consider steady state bandwidth (the blue bar) our test that carries the most weight in ranking a drive/arrays heavy workload performance. Performance after Garbage Collection (GC) (the orange and red bars) is what we consider the second most important consideration when ranking a drives performance. Trace-based steady state testing is where true high performing SSDs are separated from the rest of the pack.


We wanted to see how an enterprise like version of a 950 Pro array would perform. We accomplished this by building a 20% OP into our arrays (this is the ONLY test where we over-provisioned). Although not charted, we can tell you that 20% over-provisioning delivers about a 50 MB/s increase over a non-overprovisioned array across the board.


Over-provisioned or not, this is a huge increase in performance over a single drive in a heavy workload environment. This is the opposite of what we saw from our standard PCMark 8 testing. Do you need solid proof that a 950 Pro array is the currently best OS disk? This is it. Especially when you over-provision the array.




We chart our test subject's storage bandwidth as reported at each of the test's 18 trace iterations. This gives us a good visual perspective of how our test subjects perform as testing progresses. What jumps out at us is just how little performance variability in degrade and steady-state phases of the test the Samsung drives display.


Intel's 750 produces a pronounced wave pattern displaying significant variability. This chart makes it very clear that overall a single 512GB 950 Pro is easily outperforming the 1.2TB 750 series in terms of storage bandwidth for 85% of the entire test. The performance of both 950 Pro arrays is downright amazing!


Total Access Time (Latency)


We chart the total time the disk is accessed as reported at each of the test's 18 trace iterations.




Look at what over-provisioning can do from a latency prospective. Our dual 256GB 950 Pro array with 20% overprovisioning has seven times lower latency than a single drive.


Disk Busy Time


Disk Busy Time is how long the disk is busy working. We chart the total time the disk is working as reported at each of the tests 18 trace iterations.




When latency is low, disk busy time is low as well.


Data Written


We measure the total amount of random data that our test drive/array is capable of writing during the degradation phases of the consistency test. Pre-conditioning data is not included in the total. The total combined time that degradation data is written to the drive/array is 470 minutes. This can be very telling. The better a drive/array can process a continuous stream of random data, the more data will be written.




This test is the real reason we wanted to show what over-provisioning can do. The Intel 750 has OP built-in, which is why it can write so much more random data than a single 950 Pro without any OP. We used 20% OP on our 950 Pro arrays which resulted in up to nine times the data being written in comparison to a single non-over-provisioned 950 Pro. Although not charted, without OP, a 950 Pro array is able to write 2-3x the data of a single non-over-provisioned 950 Pro.


In terms of sustained random write performance, over-provisioning is the main difference between an enterprise SSD and a consumer SSD. We can clearly see why manually over-provisioning an SSD that doesn't have any built-in is advantageous.

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