Multiple PC OEMs are selling laptops outfitted with Intel Optane cache drives — but they’re improperly combining that information in ways that makes it seem as if the Optane cache drive represents some kind of DRAM rather than a conventional cache drive. Meanwhile, Intel has made explicit changes to its own Optane marketing FAQs that appear to greenlight this positioning. It’s a situation that could lead end-users who aren’t careful to draw very incorrect conclusions about what kind of system they are buying and what its capabilities are.
We’ve seen this happen so far in two cases, one involving Dell, one HP. First, here’s the Dell search done via Google (these results were correct when we began this article, but after reaching out to Dell for comment on the story, the Google Shopping link we’re going to show you vanished).
Note the way the system is identified as having 24GB of RAM? If you actually click through the ad, you’re dropped off on this page, where the system configurator clarifies that what you actually have is “24GB of Memory: 8GB 2666MHz DDR4 DRAM + 16GB Intel Optane memory.” It appears that Google’s search engine is misunderstanding Dell’s configurator, specifically, because an HP system up for sale does identify up-front that the 24GB of “memory” listed for sale again consists of 8GB of DDR4 and 16GB of Optane.
Even if we allow for a listing issue leading to a problem with the Dell results, the HP framing is disingenuous at best. Many consumers already struggle to understand the difference between “memory” and “storage” and tend to conflate the two concepts. Pretending that cache drives are a form of RAM not only misrepresents the situation, it risks further confusing buyers.
Optane Caches Aren’t DRAM
In March 2017, Intel launched the first PC client Optane drives meant for conventional desktops and laptops. These systems integrate a 16-32GB Optane cache, and they use it to accelerate a conventional hard drive’s read/write performance in a manner that’s similar to using an SSD cache to perform the same task. Importantly, and in all cases, these cache drives are explicitly a part of the storage subsystem in a PC, not the DRAM subsystem.
Optane cache drives connect to their host systems via an M.2 port, which means they connect over the southbridge-attached PCIe bus. They are not attached to the system via its RAM slots like an NV-DIMM. They are not identical or equivalent to the Optane Persistent Memory DIMMs that Intel announced a few weeks ago.
Anandtech makes this point directly in their recent review of a 64GB Optane cache drive, writing:
[I]t is clear that no amount of fast storage can make up for a system crippled by too little RAM, which is a disappointment in a time when SSDs are getting cheaper but RAM prices are still climbing. Optane SSDs may be the fastest swap devices money can buy, but they’re no substitute for having adequate RAM.
This point is made in the site’s Sysmark 2014 SE results, which tested a Core i7-8700K and Core i5-7400 with multiple Optane drives. In the graph below, only the Optane SSD 900P is being used as a stand-alone SSD. The 8700K system is outfitted with 16GB of DDR4-2666, while the i5-7400 has 4GB of RAM. You can see the full results at Anandtech, but we’ve highlighted the data and financial analysis results:
Both the Core i5-7400 and 8700K see performance improvements when moving from a conventional HDD to an Optane cache, but they don’t see the same degree of improvement. The Core i5 picks up just 8 percent from this shift, while the 8700K gains 16 percent performance. Anandtech’s review also indicates that the i5-7400 did a great deal of heavy paging back and forth, indicating that this may be part of why there’s such a performance gap in the benchmark run itself. Considering Anandtech’s Bench also records a Core i3-7100 scoring a 1086 in the same benchmark, it’s clear the Core i5-7400 is hitting a hefty penalty.
Combining DRAM and Optane cache drive capacities and pretending this refers to a single contiguous memory pool is a lie. The 16GB of Optane in these systems is not DRAM. It cannot be configured to act as DRAM. It cannot, in any way, shape, or form, be used as a substitute for DRAM. Attempting to elide this distinction by referring to a more generic word like “memory” is a cynical and shameful attempt to take advantage of a well-known point of confusion among consumers by companies who damn well ought to be clarifying such questions for their customers, not seeking to mislead them.
Yes, the HP ad and Dell’s website both clarify that the “memory” pool is composed of two distinct types of memory, but only after first implying that the two work together in some fashion — because if they don’t, why are they combined in the first place? Consumers who don’t understand the difference between a 16GB Optane cache and 8GB of DDR4 to start with won’t magically understand that one of these terms refers to a small storage pool used to cache frequently accessed hard drive data while the other refers to the amount of memory available for actively-running programs and tasks. They’ll just assume they’ve got two different kinds of RAM for some reason and 24GB of total usable capacity.
Far from opposing this kind of messaging, Intel appears to be obliquely encouraging it.
Intel’s FAQ Reversal
On June 19, 2017 Intel published a FAQ on Optane memory and its uses. Included in that FAQ were the following questions:
Note the unambiguous phrasing. Intel Optane improves performance because it sits closer to the CPU than other types of storage. This allows the system to access information more quickly and improves system responsiveness. No, you cannot use 16GB of Optane and 4GB of DRAM to meet the requirements of a game that requires 8GB of DRAM, because Optane and DRAM are not the same thing.
Now, compare that with Intel’s more recent Optane FAQ.
What is Intel Optane memory and why consider it memory?
Intel Optane memory is a system acceleration solution for new 7th Generation Intel® Core™ Processor-based platforms or later. This solution uses the Intel® Optane™ Technology, based on 3D XPoint™ Memory Media. It uses the Intel® Rapid Storage Technology (Intel® RST) driver. This new memory media is located between the processor and slower SATA-based storage devices (HDD, SSHD, or SATA SSD). It can store commonly used data and programs closer to the processor so the system can access information more quickly with improved overall system responsiveness.
Intel Optane memory concatenates memory and storage into one virtual drive visible to the OS with an optimized system interconnect. It uses smart software like Intel RST to accelerate performance and responsiveness of the PC. Intel Optane memory is called memory because it uses a new memory media to store information closer to the processor. It’s similar to the function of dynamic random access memory (DRAM). (Emphasis added)
The first paragraph is more-or-less identical to what Intel ran before. It’s the second sentence of the second paragraph that’s new — and it explicitly argues that Optane should be considered as “similar” to the function of DRAM. At a high conceptual level, you can make that argument. It completely falls apart when translated into product marketing that pretends a 16GB pool of Optane and 8GB of DRAM add up to 24GB of memory.
Intel’s FAQ has been altered in one other way. The messaging about how you can’t use a 16GB Optane cache and 4GB of DRAM to play a game that requires 8GB of RAM has been removed. Under the “Why do I need DRAM if I have Intel Optane memory?” the answer reads “Intel Optane memory system acceleration doesn’t replace the DRAM in your system. It works alongside the DRAM to provide the best possible performance.”
That answer isn’t wrong — but it’s lacking the explicit example in the earlier FAQ that made it clear that DRAM and Optane could not substitute for one another.
An Unlikely OEM Initiative
Neither Dell nor Intel got back to us before this article went to print, so we have no formal comment from either company. But there are a few points to draw out here:
First, it’s unlikely that Dell and HP just happened to come up with this messaging idea on their own. Intel takes its branding and messaging extremely seriously, particularly when it comes to communicating the capabilities of Intel platforms to consumers. Pushing the idea that a computer’s “real” amount of memory is its Optane cache + RAM accomplishes two things: It drives consumers towards preferentially picking these systems over Intel systems without Optane (helping Intel move more cache drives) and it creates a marketing situation that Intel’s competitors (AMD and hypothetically ARM) can’t match without encouraging OEMs to also treat NAND SSD cache drives as if they were RAM-equivalent — and they aren’t. Intel’s FAQ attempts to anticipate this outcome by claiming that it’s Optane, specifically, that ought to be considered as equivalent to DRAM because of Optane’s unique characteristics, ignoring that these characteristics are invalid to any question of whether or not a 16GB storage pool attached via PCIe is equivalent to DRAM in the first place.
Second, this messaging is consumer-hostile. It conflates two very different types of memory as if they were equivalent and it works against every effort the IT industry has collectively made to explain these differences for the past few decades. If these drives were Optane DC PM products, Intel would have an argument to make — those products do (or will) use Optane DIMMs as if they were DRAM. But Optane cache drives are not Optane DC Persistent Memory. They’re M.2-connected drives that somewhat outperform NAND-based SSDs with better endurance ratings.
Third, and most importantly, this makes Optane look needlessly bad for no reason whatsoever. It positions the drive as if it were a DRAM-equivalent technology when it isn’t. Customers who buy these systems and expect to get 24GB of DRAM-equivalent performance are going to be extremely unhappy when they don’t get it — and all the frantic hard drive paging that results is going to be a clue that they didn’t buy what they thought they did.
When Intel unveiled Optane back in 2015, it made a lot of noise about how it had invented a new type of storage, and how rare and unusual it was for this to happen. At the time, it wasn’t clear how much of this PR was justified and Intel took its time when it came to bringing Optane to market. The rollout has been gradual, starting with the first cache drives last year and continuing on through to the Optane DC Persistent Memory announcement a few weeks back. There’s still a lot we don’t know about Optane, including the specifics of the underlying memory technology.
But over the last 12 months, it’s become clear that Optane really is something new and different. It offers performance at low queue depths that no NAND-based SSD or PCIe drive can match. Its reliability and endurance ratings are excellent. It can plausibly be used as persistent memory in ways that NVDIMMs, again, will struggle to match if they can match them at all. True, Optane hasn’t exactly eaten the consumer market by storm — but neither did SSDs at first. It took years of steady improvements and price reductions before even most enthusiasts were willing to pay top dollar for an unproven storage medium.
I’ve covered new and emerging memory technology for a number of years. Even if Optane is fundamentally based on phase change memory, as has been theorized, it’s quickly ramped from a hypothetical “someday” solution that might challenge NAND and DRAM eventually and into a product that’s taking on NAND and DRAM today. I don’t pretend to know how quickly Intel can bring costs down or how well it will continue to scale into the future, but it’s possible that Optane has a real, or even primary role to play as a computing solution for exascale and beyond. If it does, the total amount of money Intel will make selling Optane cache drives from now until the end of time doesn’t even represent a rounding error compared to how much cash it’ll make off Optane in the enterprise, HPC, and enthusiast markets.
But until Intel launches Optane Persistent Memory for mainstream desktops and laptops and positions it as a total DRAM replacement, Optane isn’t DRAM-equivalent. Optane cache drives have no business being marketed as “memory” in this dishonest, misleading fashion. Frankly, the technology deserves better — and so do customers.
Now read: How Do SSDs Work? and PCMag’s Best SSDs of 2018