Intel’s Optane SSD DC P4800X and its underlying 3D Xpoint memory technology seem poised to bridge a performance gap between NAND density and DRAM performance in certain types of datacenter workloads, but that $1520 device isn’t meant for the average PC builder in the least. Intel still has ambitions for Optane in client PCs, but competing with NAND SSDs on both a speed and capacity basis would prove prohibitively expensive given Optane’s roughly $4-per-gigabyte cost right now. Instead, Intel is taking a different tack for the moment: improving the performance of hard-drive-only systems for a reasonable cost.
The company says that people considering desktop PCs want three things above all: performance, security, and storage capacity. Right now, hard drives tick the capacity box, but anybody who’s used an SSD knows that spinning rust doesn’t perform anything like flash. Hard drives still make up the vast majority of storage devices shipping in today’s PCs, however, and Intel anticipates that’ll continue to be the case for the foreseeable future.
Enter Optane Memory. Intel’s first client Optane product uses a hardware-and-software stack that purports to cache a user’s most commonly accessed files on a fast slice of PCIe 3.0 x4-connected storage. Its reliance on newer tech aside, Optane Memory as a whole sounds similar in principle to what Apple does with its Fusion Drive-equipped iMacs. It also sounds similar in principle to Intel’s own Turbo Memory technology, a small slice of NAND on a riser card that did basically nothing for system performance when it debuted in some notebooks back in 2005. Given Intel’s history with elaborate solid-state caching layers, I was skeptical about the prospects of another take on the idea. Optane has some fundamental differences that promise a better showing this time around, however.
For one, Optane doesn’t need a large number of dies to achieve maximum performance like most NAND devices do, so one Optane die (as one will find on Intel’s 16GB Optane Memory device) or two dies (as found on the 32GB gumstick) should offer enough parallelism to deliver a performance increase over devices with small amounts of NAND on board, like SSHDs. Even more importantly, Optane Memory devices enjoy the same class of high QD1 performance that the SSD DC P4800X does, so they can offer maximum performance at the low queue depths typical of desktop workloads.
For its part, Intel thinks Optane Memory will boost system responsiveness above all—the major beef with hard-drive-only PCs. Using the Sysmark benchmarking suite, the company claims only minor increases in application performance, but the suite’s responsiveness test comes away with twice the performance of a system with a hard drive alone.
To bolster the point that QD1 performance matters most for desktop users and that Optane is ideally suited to boosting system responsiveness, Intel shared some internal data about the read and write queue depths for the synthetic PCMark Vantage benchmark and some demo workloads from its labs.
Intel also performed trace analysis for the launch performance demands of several commonly-used applications one might find in the typical workplace.
Finally, Intel collected application traces from a number of its employees’ PCs to show the queue depth demands of more productivity-focused workloads.
The point of these graphs is clear: most random desktop workloads level off at about QD4, and the majority of accesses happen at QD1 or QD2. Given those characteristics, Optane Memory seems ideally suited to speed up application launches and perhaps to lessen the wait for commonly-accessed files, at least so long as those accesses are primarily random. Presuming that’s the case, Optane Memory seems much better poised to offer some kind of speedup to a user’s commonly-used applications than a small NAND cache like Turbo Memory might have.
Optane Memory isn’t much good without its companion software, an unobtrusive utility that sits in the system tray. Intel says this application will render the Optane cache transparent to the user experience. The only storage device that should show up with an Optane Memory system is the user’s primary system drive (along with any other non-Optane Memory storage devices that may be installed). There’s a lot of black-boxiness to how the app’s caching algorithm works, but Intel suggests Optane Memory won’t be caching entire applications like games on the Optane device itself, simply because they’d often be too large to fit in 16GB or 32GB of space. Instead, I got the impression that the Optane Memory app will look for common files (like shared libraries and operating system files) that are often accessed by many programs and cache those instead.
Some early thoughts about performance and pricing
While we were at Intel’s Folsom, CA facilities recently, I got some hands-on time for comparison testing with an Intel-provided Optane Memory module and a compatible PC equipped with a hard drive and Windows 10. Intel allowed us to run some canned tests on these Optane Memory-equipped systems, and after comparing first-launch performance with second-launch performance, the Optane Memory cache did shave off a few seconds of launch time from each application available to us (the GIMP, Blender, and FL Studio). We’ll need to do more comparison testing to get a full idea of what Optane Memory offers, but users should at least enjoy some net benefit from this technology if it comes installed in a given PC.
Given how aggressively Optane began caching programs after even one program load, the tech should have near-immediate benefits for PCs with the Optane Memory software installed. It remains to be seen how extended use will affect what can remain in the Optane cache, and we also need to test a broader range of applications than the almost certainly cherry-picked choices that Intel made on the testing PCs available to us. Still, there is a definite benefit to Optane Memory when it works. We’ll just need more time with Optane Memory—and time with a broader range of comparison systems—to see whether the tech is actually worth it.
The most pressing question about any whiz-bang new storage technology is whether it’s worth the cost to add it to a system to begin with. Thankfully, Optane Memory is relatively affordable. Intel told me that the 16GB version of the device will retail for $44, while the 32GB device will go for $77.
The cost of entry for the 16GB Optane Memory cache seems reasonable enough that budget builders trying to get both capacity and responsiveness might not have to break the bank. Adding the 16GB Optane Memory device to our B250-chipset-powered budget box would take its price from $500-ish to $550-ish. The same $100 or so (between a WD Blue 1TB and the 16GB Optane Memory cache) gets a nice 250GB-class SSD, but such a drive will fill up much faster than the WD Blue.
The problem for Intel in the DIY PC world is that builders will be weighing that extra $45 and thinking about putting it toward a more powerful graphics card like a Radeon RX 480 4GB, which is well within the range of attainability over our GeForce GTX 1050 Ti budget pick given that extra dough. We guess many will be willing to tolerate slower boot-ups and game loading times for higher performance once an application is loaded (at least assuming a game doesn’t become CPU-bound, as it might with a Pentium G4620 and an RX 480 4GB). Still, Optane Memory might prove to be an affordable way to spiff up a hard-drive-equipped PC on a budget without sacrificing capacity.
I’m less enthused about the prospect of pairing Optane Memory with an NAND SSD in a more expensive system like our Sweet Spot build. Intel still claims that users will experience benefits from pairing Optane’s unique QD1 performance characteristics with a less-responsive NAND device, but the challenge I see in that market is whether the performance difference (if there is one) is noticeable enough to be worth the price over simply buying a larger SSD. Intel might still find some takers in this market, however, since the impact of $45 to $75 extra on a high-end system isn’t that much in the grand scheme of things. Given Optane’s order-of-magnitude latency reduction versus NAND for responsiveness, I have a hunch this technology might have interesting impacts on 99th-percentile frame times in games. Just a hunch, though.
As we’ve known for some time, Optane Memory won’t work with just any system. OEMs and system builders who want to take advantage of the technology will need a seventh-generation Core (or Kaby Lake) processor and a motherboard with any 200-series chipset (B250, Q250, Q270, H270, and Z270) that has an M.2 slot. Intel explains this limited hardware support by noting it’s only performed the necessary qualification work for Optane Memory on systems comprising those two key components. Fair enough, I suppose.
Even with those limitations, an Optane Memory stick will certainly fit into any PCIe 3.0 x4-powered M.2 slot, and it’ll likely appear as an NVMe storage device to the operating system, but the tiny sizes of the intitial Optane Memory sticks make this use case little more than a curiosity.
If nothing else, Intel has seized on a real pain point for system builders on a budget. The ever-increasing sizes of photos, videos, and game installs are putting more and more pressure on storage space for affordable PCs these days, and they’re certainly outstripping the price decreases we’ve seen for a given amount of NAND flash storage. While a 128GB SSD is affordable these days, it’ll be quickly overrun by the needs of anybody with a few advanced programs and a modest Steam library. Even a 240GB-class SSD is getting harder and harder to live with these days, as I’m reminded fairly often when I need to fire up WinDirStat to figure out what’s filling up my daily-driver PC’s 840 Pro.
As I’ve noted repeatedly in the preceding paragraphs, the 1TB hard drive we recommend to budget builders lets those folks rest easy with plenty of room to store today’s increasingly belt-busting titles. The downside is that a hard-drive-only system just can’t be as snappy or responsive as a box with an SSD for its system drive. Once you’ve seen the SSD light, switching back to a box with nothing but a hard drive for storage is a grating experience. We’ll have to see whether Optane Memory eases that pain when we get an opportunity to run it through a broader range of tests soon.