Review: Intel SSD 750 Series 1.2TB

Introduction

Wipe the slate clean. That's the thinking behind the Intel SSD 750 Series 1.2TB.

Forget the SATA interface, forget the AHCI protocol. This is high bandwidth, NAND Flash-specific storage of the highest order.

This is solid state all grown up and with Non-Volatile Media Express (NVMe), and it's forging its own path free of the past.

Since the first consumer SSDs started hitting our PCs they've all been piggy-backing old school, high-latency mechanical drive technology in terms of their interfaces and protocols.

In the beginning of the SSD revolution running across the 600MB/s limit of the SATA 6Gbps interface wasn't much of a problem. Quickly our SSDs became more trustworthy and more capable, and suddenly they were bumping their heads against the limits of the suddenly geriatric-looking connection.

Along came PCIe-based drives, though they were mostly still just groups of smaller SATA drives connected to a PCIe RAID controller.

Then recently came actual, proper, honest-to-goodness PCIe interfaces specifically designed for SSDs, and the new wave of Flash storage had begun. The M.2 socket and the still mostly unused SATA Express arrived with the Intel Z97 and X99 chipsets.

But breaking clear of the bandwidth limitations of the SATA interface is only one strand in unlocking the true potential of solid state storage. The other is about getting around the legacy setup all previous SSDs have been tied to.

The old Advanced Host Controller Interface (AHCI) protocol was introduced when SSDs where a mere twinkle in an old USB stick's eye, and has been almost inextricably linked to high latency spinning platters.

That setup still works fine for mechanical storage drives, but the legacy commands in AHCI still have to be run through, even when an SSD is in place. The drive then has to go through each legacy command even if they have no relevance to high-speed SSDs.

And that wastes an awful lot of CPU cycles.

This is where the NVMe protocol steps in, designed specifically for Flash memory without all the legacy hoops in place for the ol' spinning platters.

Technology and architecture

The difference between the NVMe and AHCI protocols were ably illustrated when Intel introduced its enterprise level DC P3700 NVMe drive, the predecessor to the Intel SSD 750 1.2TB.

There it used the Linux AHCI stack as an example of the wasted time and power that goes into running an SSD across the legacy protocol.

Using a quad-core i5, the Linux stack runs to 27,000 CPU cycles, which means it needs a full ten Sandy Bridge-level cores to drive one million IOPS (input/ouput operations per second). With the streamlined NVMe Linux stack that's cut by around a third, it only needs 10,000 CPU cycles to get to the magic million figure.

This is because the new protocol has been designed specifically for NAND Flash storage and this low-latency access now means SSDs are capable of standing on their own without needing any old tech from the mechanical days of storage.

The slate has been wiped clean and we can kick on from here getting at the true speed of SSDs.

And that enterprise P3700 drive is important, not just for providing an example of how powerful the NVMe protocol can be, as it forms the basis of this Intel SSD 750 Series, the first consumer NVMe drive.

The bespoke Intel NVMe controller at the heart of the P3700 is the same 18-channel controller as the one that makes the Intel SSD 750 so darned speedy. That controller is kept honest with a hefty 2GB of DDR3 cache on this 1.2TB version.

The storage part of the equation is made up of eighty-six 128Gb NAND modules, arrayed over thirty-two separate die packages on the PCIe board.

The memory chips themselves are Intel's own 20nm MLC design. We are guessing they're 16GB modules, which would mean there's a hefty amount of over-provisioning going on inside this drive. This may be a result of its enterprise heritage, and that sector's demand for multiple redundancies.

Whatever the actual make up of the drive though there's no disputing the fact it's blazing fast.

It's also a remarkably simple drive to use too. Drop it into a waiting Gen 3 PCIe slot and watch it go.

There are certain caveats though - it needs to be at least a x4 lane slot, and it needs to be connected directly to the CPU rather than the PCH. It also needs the full bandwidth of a PCIe 3.0 slot to give the SSD 750 a chance to really stretch its NVMe legs.

Plug it into the PCH and you'll only get around half the performance.

It's also only available on Z97 and X99 boards for now.

Intel has said it would be compatible with both Z77 and Z87 chipsets, but because NVMe needs BIOS investment mobo makers are no longer spending on legacy chipsets, so it was simpler to go straight for the latest boards. Intel has been working hard over the last 6-12 months to ensure the BIOS manufacturers had the support to get things in place for launch.

That's why you'll have seen the likes of MSI and ASRock crowing about NVMe support despite a conspicuous lack of actual product to connect to their boards.

This PCIe version is fully bootable - once our Asus Maximus VII Hero board had its latest BIOS in place, it instantly saw the SSD 750, gave us the option to install our OS and boot away. Setting up the OS was a doddle too, though Microsoft's NVMe driver needed replacing with Intel's latest driver to get top speed.

There is also an Intel SSD 750 Series 400GB edition too, designed in a 2.5-inch form factor. Intel has created this for the burgeoning small form factor community who can't afford the space for a PCIe GPU as well as a PCIe SSD.

The issue with that drive though is the connection.

Intel is using an SFF-8639 connection on the drive itself, powered by a connected SATA power cable, to connect to the motherboard. The mobo makers will need to start putting SAS-based SFF-8643 sockets on their boards to accommodate the new cable from the 2.5-inch Intel SSD 750 400GB.

Intel has though said it will be producing an M.2 adapter which should alleviate some of the potential connection problems and allow it to work with existing smaller Z97 or X99 motherboards.

Performance and benchmarks

And what is top speed? The peak sequential numbers from ATTO are unprecedented.

The reads were almost 2.7GB/s and the writes were a little over 1.3GB/s. Inevitably the average scores on the more testing AS SSD benchmark were lower, but still 2.1GB/s and 1.2GB/s respectively isn't bad.

There are some interesting scores when we get to the 4k random read/write performance though.

At 30MB/s, the 4k random read speed is nothing to write home about, but the write performance of 200MB/s is stunning. That's nearly twice as quick as the closest competing drive on that front.

Compare all that with the fastest PCIe drive we've previously tested, the Samsung XP941, and you can see where the AHCI protocol is holding things back. Its 4k write performance is a quarter what the SSD 750 is capable of and the sequential performance is also lagging behind too.

It's not just in the synthetic tests where the SSD 750 shows its speed though.

Our real-world tests also have the Intel drive coming out on top, completing our 30GB Steam folder copy in two minutes flat. We noted its peak speed during transfer of around 750MB/s. That's mega quick.

We're all about consistency too and this new NVMe drive shows no problems there either, remaining at a pretty constant speed throughout the heavy PCMark 8 extended storage tests.

It wasn't consistently as quick as the PCIe Samsung drive during its PCMark testing, however.

Benchmarks

Peak sequential read performance

ATTO - MB/s: higher is better

Intel SSD 750 1.2TB - 2671

Samsung XP941 512GB - 1060

Samsung 850 Pro 512GB - 561

Peak sequential write performance

ATTO - MB/s: higher is better

Intel SSD 750 1.2TB - 1322

Samsung XP941 512GB - 997

Samsung 850 Pro 512GB - 532

Average sequential read performance

AS SSD - MB/s: higher is better

Intel SSD 750 1.2TB - 2136

Samsung XP941 512GB - 1055

Samsung 850 Pro 512GB - 506

Average sequential write performance

AS SSD - MB/s: higher is better

Intel SSD 750 1.2TB - 1175

Samsung XP941 512GB - 885

Samsung 850 Pro 512GB - 500

4k random read performance

AS SSD - MB/s: higher is better

Intel SSD 750 1.2TB - 38

Samsung XP941 512GB - 23

Samsung 850 Pro 512GB - 37

4k random write performance

AS SSD - MB/s: higher is better

Intel SSD 750 1.2TB - 200

Samsung XP941 512GB - 49

Samsung 850 Pro 512GB - 107

Real-world compression performance

5GB folder - Seconds: quicker is better

Intel SSD 750 1.2TB - 69

Samsung XP941 512GB - 73

Samsung 850 Pro 512GB - 73

Real-world transfer performance
30GB folder - Seconds: quicker is better

Intel SSD 750 1.2TB - 120

Samsung XP941 512GB - 132

Samsung 850 Pro 512GB - 169

Our testing platform is a stock-clocked Intel Core i7-4770K on an Asus RoG Maximus VII Hero Z97 motherboard with 8GB Corsair Dominator DDR3 at 1,600MHz.

Verdict

There we have it then. Intel's SSD 750 is the fastest solid state drive we have ever tested, and by a pretty comfortable margin too.

It is, however, also one of the most expensive.

The problem with being a brand new technology, and being first to market, is that it will always command a supremely high price tag. That's especially true given there is still no NVMe competition.

Couple that with the fact it's Intel, and prices were always going to be sky-high. This is like the Extreme Edition CPU of solid state drives.

But there is a certain justification for it though. Intel has had to invest heavily in the background ecosystem of NVMe, working behind the scenes to ensure that all the mobo makers are able to get BIOS support for their Z97 and X99 boards.

The SSD makers who will follow up with inevitably cheaper NVMe-based SSDs wont have that R&D cost.

There's a little bit of the Titan X about the SSD 750 Series too. It shares the basic core silicon with it's professional-class brethren, the P3700, which means it has similar levels of performance. But the enterprise drive is nearly $5,000 (£3,367, AU$6,601) while this high-capacity, high performance drive is just $1,029 (£693, AU$1,360).

Looking at the cost per GB price makes the price look more reasonable. When Intel released the X-25M, the first real performance SSD (for all its subsequent faults), it cost $3.72 (£2.50, AU$4.91 )per GB. For this 1.2TB drive that translates to only 86c/GB (£0.58, AU$1.14).

We liked

The Intel SSD 750 1.2TB is the quickest SSD we've ever tested, and that's especially impressive given that it isn't trying to do any RAID-ing shenanigans to get to that level of performance.

Incidentally, you could RAID a pair of these drives if you crave the performance, and have no other need for a couple thousand dollars, but you will then only be able to use them as storage drives. RAID on the Intel SSD 750 will stop you being able to boot.

And that's another thing that impressed us about the drive: how easy it was to get set up.

It's actually simpler than an old SATA drive because all you need do is slot it into your motherboard and away you go. Once you've got the latest BIOS installed in your board, it's smooth sailing.

And Windows saw it just as quickly when installing a new OS.

We are also pleased to see that synthetic performance did translate into real-world gains too, with the Intel SSD 750 being over a minute quicker in our 30GB Steam folder transfer. It is also great to see the 4k random writes being given such attention, double what the top SATA SSD can manage.

We disliked

Obviously that $1,029 (£693, AU$1,360) price tag is prohibitive for most of us.

Though 86c/GB (£0.58, AU$1.14) is pretty good for a brand new storage technology considering Intel's previous, it's still a huge amount of cash for normal consumers.

It's also a shame the lower capacity drive, the Intel SSD 750 400GB, is in a 2.5-inch form factor with a non-standard connection. Hopefully Intel will release smaller, cheaper versions of the PCIe drive too.

Verdict

Okay, at the risk of sounding like we're Intel apologists here…

Yes, it is a crazy amount of cash for most of us to drop on an SSD, however quick it is, but there are some places where the value of the Intel SSD 750 1.2TB is going to be seen despite that ticket price.

Intel is looking first to the consumers running with huge data sets - the digital content creators, the engineers, the visual effects guys and eventually the game makers too.

Prices will quickly tumble as well.

This is the birth of NVMe. Now that the ecosystem is there, you can guarantee NVMe-based SSDs will be appearing from every SSD manufacturer in the tech world by the end of the year.

Once Marvell and SandForce's controllers are out in the wild the market is going to go crazy. We would bet Computex in June is going to be built upon a sea of NVMe drives…

And we also doubt this is as fast as an NVMe drive can get too - without comparisons the SSD 750 looks lightning-fast, but we'll know more once competing NVMe controllers are out on the shelves and in our test rigs.

For now though, the Intel SSD 750 1.2TB is as quick as it gets.

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