The Fastest SSD – that’s what we’re out to determine today by benchmarking three of the fastest SSD products on the market: The Intel 750, Samsung SM951 and SanDisk ioMemory SX350.

Generally speaking, nothing can so improve general computer system speed as cost effectively as an SSD (Solid State Drive). It’s a key, modern factor in moving data quickly. Supporting media professionals as we do, fast storage can make a huge difference when editing in high resolutions or creating complex 3D content. Until recently, that would often look like a large RAID internally or externally.

In the last two years there’s been a revolution in the SSD arena. SATA3 Solid State performance has been at it’s technical limit for several years now, which perhaps naturally led to development around the PCIe bus with its greater bandwidth. This has led to breakthroughs in performance to be sure, but initially the cost for this performance was prohibitive. Prices have come down, but the primary point here is that in the most demanding, high stakes environments, after your people, wise investment in the best hardware available is extremely important. And wisdom, they say, comes from experience.

In this article the mediaworkstations.net team and I explore three of the top PCIe SSDs on the market: The 1.2TB Intel SSD 750 PCIe SSD, the 512GB Samsung SM951 M.2 SSD, and the 1.6TB SanDisk Fusion ioMemory SX350. Each is a structurally different card, but each is built around the PCIe bus and each offers it’s own strengths and weaknesses as we shall see.

We’ve decided to break the article into two parts. In Part I we are going to examine read and write performance of the Intel 750, Samsung SM951 and Fusion ioMemory SX350, as well as CPU usage in testing and performance consistency in 2 different IOMeter tests. In Part II, we’ll be examining real-world read and write performance with a three minute 4K DPX file in Premiere Pro CC.

Part I: IOMeter Benchmarking

Test System:

i7-X Mediaworkstation

• Intel i7-5960X 8-core CPU at 4.2 GHz
• CORSAIR Hydro Series H110 Extreme Performance Liquid CPU Cooler 280mm
• 32GB Kingston DDR4 2133 ECC RAM (4 x 8GB)
• 4GB Zotac NVIDIA GeForce GT 730 Fanless Graphics Card
• ASUS X99-E WS Motherboard
• EVGA SuperNOVA 1000 P2 80+ PLATINUM, 1000W ECO PSU 220-P2-1000-XR
• 256GB Samsung SM951 m.2 SSD (OS Drive, in onboard M.2 slot)
• Windows 8.1 Professional 64-bit

The Drives:

1.2TB Intel SSD 750 PCIe 3.0 x4 SSD – NVMe

Architecturally similar to the Intel SSD DC P3700 SSD, the Intel 750 features full power loss protection that protects all data in the DRAM, and as skillfully presented by Kristian Vättö at Anandtech here, Intel’s focus was to orient the drive for client application use by redesigning the firmware. The big news is the modest price point for this drive type. The two form factors available are the 2.5” 15mm drive using the SFF-8639 connector just beginning to make it’s appearance with hardware like the ASUS TUF Sabertooth X99 and certain enterprise products we’re explore soon), and the half-height, half-length add-in card which we used for our testing. The Intel SSD 750 is warranted for 5 years on daily writes totalling 70GB or less. Rated speeds: Up to 2.4 GB/s read, 1.2 GB/s write.

512GB Samsung SM951 M.2 PCIe 3.0 x4 SSD

The Samsung SM951 is the successor to the popular XP941. It comes in three capacities, 128GB, 256GB, and 512GB, has an M.2 2280 form factor, and is available as an AHCI or NVMe drive. In this test we test the AHCI version, which from other tests I’ve seen has remarkably similar read and sometimes better write performance than it’s NVMe counterpart. The Samsung SM951 is warranty-rated 3 years on daily writes of 40GB or less, and, like the Fusion ioMemory SX350 below, the SM951 needs ample cooling to sustain the excellent performance it is capable of. Rated speeds: Up to 2.15 GB/s read, 1.5 GB/s write.

1.6TB SanDisk ioMemory SX350 PCIe Application Accelerator

To be fair, this drive is a bit in a class all by itself. It is a true enterprise drive, which sees real practical purpose in professional media applications with 4K resolution and higher workflows and extraordinary workloads, in editing for example where dropped frames cannot be afforded. The SX350 comes in capacities of 1.3 TB to 6.4 TB and is ideal for read and write-intensive workloads, such as content caching, VFX, 3D Animation and CAD/CAM. The 1.6TB Fusion ioMemory SX350 PCIe 2.0 x8 Drive is warranty-rated 5 years on 5.5 petabytes written. Rated speeds: Up to 2.8 GB/s read and 1.7 GB/s write.

Part I SSD Benchmarking: Iometer

Iometer is perhaps the industry standard when you want to test storage performance. That said, for all its numerous strengths, Iometer is a synthetic test. What does that mean? It means you cannot run a test in Iometer, the characteristics of which will match a real world scenario due to fixed test parameters. In our tests, the que depth is 1, for example, but it’s commonly 2, 3 or 4 in many use scenarios, up to hundreds with database servers. Still, Iometer provides insight into relative performance and drive behavior (heat, throttling, etc.) in testing – and provides a detailed accounting of the results. We will be drawing analogies to real-world scenarios in this article, and in Part II we will be testing purely real world scenarios in Premiere Pro CC 2015.

Test One – 4K

In a normal desktop use scenario, I/O is roughly 80/20 write/read, and 80/20 random/sequential with 4K data block size for these reads and writes. Real windows block size workloads vary, but are largely between 512B and 1MB with a majority at 4K, so the Iometer 4K test is a good, all-around performance test.

4K Read
	IOps	MBps (Decimal)	Transactions/sec	Avg Response Time	% CPU Utilization
Intel 750	289815.37	1187.08	289815.37	0.12	14.94
Samsung SM951	153351.35	628.13	153351.35	0.23	37.68
ioMemory SX350	156021.98	639.07	156021.98	0.23	12.40

What does this reveal about the drives? For one, the numbers are well short of published maximums for each. It also shows that the Intel 750 drive is nearly 100% faster in this benchmark. Also noteworthy is the relatively significant percentage of CPU utilization by the Samsung SM951 – the other drives are much less reliant on the CPU for their performance. Given what we know of NVMe, we aren’t surprised by the lower percentage with the Intel 750, and would expect similar numbers with the NVMe version of the SM951. In short this test points to the fact that in a desktop scenario, the Intel stands out – but this isn’t likely to be evident unless these numbers stick in the 4K Write test as well.

4K Write
	IOps	MBps (Decimal)	Transactions/sec	Avg Response Time	Max Transaction Time	% CPU Utilization
Intel 750	294,190.06	1,205.00	294,190.06	0.12	15.41	23.26
Samsung SM951	131,540.81	538.79	131,540.81	0.27	8.08	61.88
ioMemory SX350	268,964.48	1,101.68	268,964.48	0.13	76.71	28.18

These write numbers match the read numbers with the Intel 750, and are at or above published maximums. The Samsung SM951 writes are nearly identical to reads in this benchmark, but the CPU utilization jumps dramatically to producing that performance, something which has me wonder how a workflow where one is reading and writing from the same disc simultaneously in (in DaVinci Resolve, or transcoding in Premiere Pro) might be affected.

Test Two: 45MB

In this test, we push all drives very hard on a very large file size. This test perhaps comes closest to resembling a true, real world professional media scenario. For example, a fluid simulation scene with huge frame sizes, or perhaps a compositing scene of many dense layers. In this test we see very different results – and terrific performance from both the SM951 and SX530.

45MB Read
	IOps	MBps (Decimal)	Transactions/sec	Avg Response Time (ms)	Max Transaction Time (ms)	% CPU Utilization
Intel 750	4.92	232.19	4.92	7232.38	8700.61	0.23
Samsung SM951	47.24	2229.09	47.24	760.46	772.29	1.35
ioMemory SX350	53.32	2515.75	53.32	674.31	1094.54	2.84

Here the Intel 750 struggles to perform at 20% of its rated ability, whereas both the SM951 and the SX350 perform at or above their published maximums. This test’s characteristics help indicate that certain scenes with heavy sequential demands (say a particle simulation scene in Maya with 20-100MB frame sizes) will be well served by both the SM951 and SX350, but will struggle with the Intel 750.

45MB Write
	IOps	MBps (Decimal)	Transactions/sec	Avg Response Time (ms)	Max Transaction Time (ms)	% CPU Utilization
Intel 750	18.43	869.69	18.43	1,946.65	2,145.59	1.24
Samsung SM951	30.54	1,440.95	30.54	1,157.37	7,745.90	3.12
ioMemory SX350	34.68	1,636.34	34.68	1,035.37	1,467.72	4.05

Here too the Samsung is near published performance maximums, and the Intel 750 is much improved over the read performance but still just 60% of it’s rated write capability. One thing noteworthy on this test – about two minutes in (each test ran 3 minutes total) the Samsung throttled to about 20% of this performance, or just over 200 MB/s. Re-running the tests with case fans on high eliminated this, indicating the need for strong cooling to avoid thermal throttling. This was also the case with the Fusion SX350 – without strong direct cooling the SX350 quickly throttles.

We next ran 256K and 512b tests. However, after trying to find a real-world corollary for these tests and coming up empty handed, we reached out to Kristian Vättö at Anandtech who said:

256KB is actually not “realistic” at all because Windows has a maximum IO size of 128KB, meaning that larger IOs will be broken down to 128KB chunks. As for 512b, that’s a rather rare IO size (only 2-3% of all IOs in our experience) and would likely reflect an update to a log file or another very minor write operation (most 512b operations are write).

In other words, 256K is not a practical metric at all, and 512b reads or writes will comprise only a tiny part of any pro media workflow, if any.

Iometer, for all its strengths is still a synthetic test. The 4K test is helpful, and for media professionals, the 45MB test is a good indicator of what you might expect working with high resolution professional media, or any such application where is a key factor in workflow speed such as fluid sim, 4K playback, heavy particles or 2K stereo use.

Which leads us to Part II: real world drive performance of the Intel 750, SM951 and SX350 with 4K DPX files in Premiere Pro CC 2015.

Part II SSD Benchmarking: Premiere Pro CC 2015

We chose to benchmark read and write performance for the Intel 750, Samsung SM951 and ioMemory SX350 using a 4K DPX file in Premiere Pro CC 2015 because the application is so common with our clients, and because a fast media drive in any 4K workflow is so important. Uncompressed file formats are important here because if you want to test performance in a true 4K workflow, you must use 4k uncompressed files on your timeline to show you what works and what doesn’t. While frame rates are valuable, data transfer rates and dropped frames are key indicators for drive viability. We were really curious – and surprised by some of the findings.

Read Performance

Intel 750

 

Given this is the most basic i/o function if working on a 4k timeline, the Intel 750 is immediately eliminated from consideration. With nearly 50% of frames dropped, using this drive in this scenario would mean proxies, and there are plenty of more cost effective drive solutions going that route. Add to this a dismal frame rate of just over 50% of target FPS and your editing experience will be nothing but choppy. Though we did not test it, sequential performance is so poor here it is conceivable the Intel 750 would drop frames even if editing HD (2K).

Samsung SM951

The Samsung SM951 fared better, but still dropped 24% of frames with the 4K DPX file, though the frame rate is respectable at 22-23 FPS.

Sandisk ioMemory SX350

Only the SanDisk ioMemory SX350 proved fully capable of handling 4K DPX files error-free in Premiere Pro CC. We suspected this going in, given the ample over-provisioning of NAND and controller-less, more-akin-to-RAM architecture and lofty price. Truthfully a fairer drive comparison of the SX350 would be with the Intel P3600 and P3700 drives.

SUMMARY: Premiere Pro CC 2015 – READ (4K DPX File)
	Display FPS (Target 29.97)	Rendered FPS	Total # Frames	# Frames Dropped	Avg. i/o (MB/s)	% Dropped Frames
Intel SSD 750	16.17	16.33	5803	2689	545	46.34%
Samsung SM951	22.76	23.03	5801	1394	583	24.03%
ioMemory SX350	29.97	32.24	5803	0.00	1090	0.00%

Write Performance (Adobe Media Encoder)

To gauge write performance we encoded our 4K DPX file to 4K DPX using Adobe Media Encoder. Of course encoding means simultaneous read and write, but this too is such a common task in Adobe CC it was an obvious choice for benchmarking.

Intel 750

Surprising, right? We are not comparing any SATA SSDs in this article, but that may have been useful here. A combined i/o (Read and Write) of 458 MB/s is a respectable SATA3 SSD spec. Intel positioning this drive to be a leader of the pack in the cost-effective NVMe SSD space is well and good but hardly tenable with performance like this. Response time was also double in the write vs. read results.

Then we tested the SM951.

Samsung SM951

This is no better, really, though the response time is better and there’s a better read performance.

ioMemory SX350

Again the SX350 led the pack, but just. The SX350 read and writes speeds in Premiere Pro CC while encoding are disappointing, especially when you consider the $3,000+ price point which is some 3 times the cost of the Intel 750 and roughly 7 times the cost of the Samsung SM951.

SUMMARY: Premiere Pro CC 2015 – WRITE (Encoding 4k DPX to 4k DPX)
	Read (MB/s)	Write (MB/s)
Intel SSD 750	201	257
Samsung SM951	201	282
ioMemory SX350	212	300

Conclusion:

There’s only one really – that PCIe SSD storage in pro media environments, especially if your intention is real time performance with 4k uncompressed footage and full data integrity is: We’re not there yet, at least in a single drive. Though we used the AHCI version of the Samsung SM951, it is much better than the NVMe Intel 750 in most tests at less than half the price. And given that the SX350 is over $2,000 more than the SM951, it only makes sense in a pure 4K workflow…and if you’re working in 5K or 6K you’ll want to RAID a pair for error-free work (i.e. no dropped frames).

The Intel 750 provided performance consistent with Intel’s claims only in the 4K Iometer test. While helpful, Iometer is a synthetic benchmark – and synthetic benchmarks are synthetic truth, they are not the real thing. We would have liked to benchmark a particle sim test in Maya with these drives for example and we may yet, as the 45MB test gave some indication of what one might see in a particle simulation scene, as you often work with huge frame sizes rendering fog, water and the like. Only in the 45MB test did we see the kind of awe inspiring speeds these companies claim their drives are capable of, and it was only the SM951 and the SX350 which delivered – on the 45MB test the Intel 750 read performance was a dismal 10% of spec claims, and write speeds, while respectable, were still only 60% what Intel says the drive can do.

So which is the fastest SSD? We can say the SX350, but none of these drives are really mature yet, technologically speaking. Though these drives have stunning performance in specific situations and everyday use, they do not have the consistency of top SATA3 SSDs like the Samsung 850 Pro for example, even if those drives are slower. Before we say this applies in all situations we need to do more testing – we are especially interested for example testing these drives in Davinci Resolve, but also demanding particle sim scenarios or work in hi res stereo where huge frame sizes demand the utmost of any drive.

Our recommendation? If you must have error-free real time performance in 4K or higher, the ioMemory SX350 Drive is a solid choice. You should however have 2 x SX350 in RAID0 if you have lots of complex picture in picture, effects etc. or you want to work in 5K or even 6K, and if so these cards MUST be kept cool with direct fans on high settings in your workstations. If you can work in HD or proxies and upres for final, the Samsung SM951 is the best drive in the world right now when it comes to price-for-performance, but it too must be kept cool. The Intel SSD 750 is not really a contender here. Per other articles we’ve seen and our own results in Iometer, this drive will do much better in random read and write scenarios, not the uncompromising sequential performance required by most media professionals day in and day out.

Special thanks to Mark Noland of SanDisk for his knowledge and sense of humor, as well as Kristian Vättö of Anandtech for his feedback and deep expertise in all things solid state.