This past summer, I put a set of fancy racing wheels on my road bike. They're a study in aerodynamic lightness: deep rims and only as many spokes as is absolutely necessary, all spun from deliciously sexy carbon fiber. I race occasionally and ride quite a lot, so it wasn't too difficult to justify the indulgence. Over the years, I've learned that I'm in tune enough with my bike to detect the sometimes subtle impact that high-end gear can have on my riding experience.
The wheels made a difference immediately. Within minutes, I noticed that the bike was accelerating quicker under power, especially when going uphill. On downhills, I found myself holding a little more speed. Rough pavement felt smoother thanks to the compliance built into the carbon spokes, too.
Put those wheels under a casual rider, and he might not notice. But I am not a casual rider... much like PC enthusiasts are not casual computer users. Enthusiasts spend multiple hours a day sitting in front of systems they've optimized for optimal performance. We're a discerning bunch, and solid-state drives are our fancy racing wheels.
That's right, I just defied this industry's longstanding tradition of car analogies to drag out my 10-speed. Deal with it, because the shoe fits. SSDs speed system performance in ways that are often subtler than the impact of a faster CPU or graphics card. Thanks in part to near-instantaneous access times, solid-state offerings are much more responsive than mechanical hard drives. They seem to never get hung up, an attribute that effectively smoothes out any bumps in the road. At least as far as PC hardware goes, SSDs are also pretty sexy.
Among the solid-state drives available for purchase today, Intel's 510 Series is the fresh new face. The drive comes more than a year and a half after Intel released its second-generation X25-M, and it's just the beginning. Intel says the 510 Series is the first of a number of new SSD products due out this year. One of those drives will feature the long-awaited successor to the flash controller behind the X25-M line. The updated controller is being designed in-house by Intel, but it's not finished yet.
Rather than using one of its own controllers, Intel has equipped the 510 Series with a Marvell 88SS9174 controller familiar from Crucial's RealSSD C300. This is a major shift for a company that has made a habit of tying together its semiconductor products. Seeing a Marvell controller on the 510 Series' circuit board is kind of like popping the hood of the latest Ferrari and finding an engine from Porsche. You didn't expect me to avoid car analogies completely, did you?
The decision to use third-party controller silicon makes sense if you step back and realize that Intel is in the business of selling solid-state drives rather than flash controllers. If Intel has multiple new SSD products due out this year, it's not unreasonable to expect some variety on the controller front. Besides, the chip giant says that modern controllers are much improved over the often-flaky initial offerings that the X25-M was designed to combat. Intel is confident enough in the Marvell chip to use it in a high-end SSD.
While Crucial's RealSSD C300 uses a Marvell 88SS9174-BJ2P controller, the 510 Series is equipped with a slightly newer BKK2 revision of the same silicon. When asked how the BKK2 differs from the BJ2P, Marvell told us the newer revision is a "comparable device." According to Intel, the hardware behind the 510 Series' controller chip is identical to what's available in competing products.
What makes the 510 Series' implementation of this particular chip unique is the firmware that comes loaded onto the drive. Intel has optimized the firmware to improve sequential throughput and to make the most of the controller's 6Gbps Serial ATA interface—you know, the one that nicely matches the high-speed SATA ports in new Sandy Bridge motherboards. We couldn't get Intel to reveal any specifics on exactly how the firmware has been tweaked, probably because it doesn't want competitors catching wind of its approach. The firmware tuning present in the 510 Series won't be shared with other SSD makers using the Marvell chip.
|Flash controller||Marvell 88SS9174|
|Flash type||Intel 34-nm MLC NAND|
|Available capacities||120, 250GB|
|Sequential reads||450MB/s (120GB)
|Sequential writes||210MB/s (120GB)
|Random 4KB reads||20,000 IOps|
|Random 4KB writes||8,000 IOps|
|Read latency||65 µs|
|Write latency||80 µs|
|Idle power||100 mW|
|Active power||380 mW|
|Warranty length||Three years|
Based on the 510 Series' performance specifications, it looks like Intel's firmware fiddling paid huge dividends. The drive's 500MB/s sequential read rate is quite impressive, as is the 315MB/s write speed. Those figures apply to the 250GB drive on a 6Gbps interface. 120GB versions of the 510 Series are a little slower, especially when it comes to sequential writes.
Regardless of drive capacity, the 510 Series promises to churn through 20,000 random 4KB reads and 8,000 random 4KB writes. Surprisingly, those specs are less impressive than the 35,000 random reads and 8,600 random writes offered by the latest X25-M. Crucial's RealSSD C300 claims random 4KB read and write performance of 60,000 and 45,000 IOps, respectively, so it's clear that Intel's optimizations for sequential throughput have cost the 510 Series in other areas.
Intel wouldn't confirm whether wear-leveling or garbage-collection components of the 510 Series' firmware have been tweaked. However, it did concede that, with typical client workloads, the drive's write amplification factor is "about the same" as that of the X25-M. The write amplification factor determines how much flash capacity is consumed by every host write, so it has a hand in dictating a drive's useful life.
The other part of the lifespan equation depends on the flash chips used. Rather than jumping to 2x-nm NAND, the 510 Series uses 34-nano MLC flash chips built by Intel's joint venture with Micron. 16 of these chips dot the 250GB drive we'll be testing today—eight on the top of the circuit board and another eight on the back. The chips conform to the ONFI 2.0 spec, which allows for per-chip transfer rates up to 133MB/s.
Although the Marvell controller's eight memory channels fall two short of the 10 channels provided by the X25-M, the old Intel controller is an ONFI 1.0 affair that caps per-chip transfers at 50MB/s. The 510 Series may have fewer channels, but each one should be quite a bit faster. With 128MB of DRAM memory onboard, the 510 Series also has four times the cache of its predecessor.
As you may have gleaned from the 510 Series' available capacity points, the drives use a typical overprovisioning percentage of about 7%. Users can increase the amount of flash capacity allocated to "free area" (essentially a working space used by the drive's controller) by leaving a chunk of the drive unpartitioned.
Like most new SSDs, the 510 Series' retail box contains a handy mounting bracket that allows the drive to slide into the 3.5" bays common in desktop enclosures. You also get a Serial ATA data cable and power adapter. Free drive-cloning software is offered on Intel's website for folks who want to transition from an existing drive.