Intel has had a prominent role in the consumer solid-state drive (SSD) market since it launched its 80GB X25-M SSD back in 2009. The chip giant has followed up with refreshed devices at regular intervals, most recently with the 335 Series. The 180GB 335 Series drive we're reviewing today is the second SKU to launch; Intel shipped a larger 240GB model last December. This new drive is a decent performer, but its reliance on older controller technology leave it wedged in the middle of the pack.
There's not much difference between the new SSD 335 Series drives and the 330 Series, which launched a little over a year ago. Both the 330 and 335 families use the SandForce SF-2281 controller. Both offer SATA 6G support, a three year warranty, and the same base performance specs (500MBps sequential read and 450MBps sequential write).
The older drive uses 25nm MLC NAND, while the newer 335 Series is based on Intel's 20nm NAND. SSDs aren't known for drawing much power, but the 335 is specced as having a maximum power draw of 350mW, with idle power consumption of 275mW. That's significantly less than the SSD 330 Series, which was specced for 850mW under load and 600mW at idle.
Save for the reduced power consumption, the shift to 20nm NAND is mostly an advantage for Intel, rather than a direct benefit to consumers. The 20nm NAND is significantly smaller than 25nm NAND, which means Intel can fit more memory chips on a given silicon wafer. The shift to smaller manufacturing geometries (also called nodes) is one reason why the price of SSDs has dropped precipitously in the past few years. The new 20nm NAND chips (shown to scale in the image below) are just 40 per cent of the size of the 34nm NAND Intel was using four years ago.
Intel drives tend to carry a fair amount of additional (overprovisioned) Flash. The 180GB SSD 335 actually contains 192GB of RAM; the additional 12GB is rotated into use as blocks of the original 180GB wear out and need to be retired. One of the downsides to using NAND built on a smaller process is that the memory can't handle as many program/erase cycles. Despite this trend, Intel rates the SSD 335 as robust as the previous SSD 330 family.
We compared the 180GB Intel SSD 335 against the Samsung 840 Pro Series 256GB and the OCZ Vector Series VTR1 256GB. Our review unit was tested using an Asus P877V-Deluxe motherboard with 8GB of DDR3-1600 RAM and an Intel Core i7-3770K CPU. The P877-V Deluxe offers multiple SATA controllers from Intel and Marvell; all of the drives were connected to Intel's 6G SATA port.
Of principle interest here is whether the 335's older SandForce controller can keep up with newer options from OCZ and Samsung. The SF-2281 controller has mostly been popping up in budget drives of late, and SandForce is expected to launch a new SF-3000 controller series later this year.
The performance figures for AS-SSD and SiSoft Sandra tests reflect a drive's performance in a particular type of data workload. Sequential read/write tests measure an SSD's capabilities when reading or writing a large block of contiguous data. A single large movie or ISO image will test a drive's sequential performance (assuming that the target drive isn't badly fragmented).
In AS-SSD, the Intel 335's sequential read speeds weren't far off the OCZ Vector and Samsung 840 Pro (465MBps compared to 509MBps and 518MBps respectively), but sequential write performance was significantly lower. The Intel 335 managed 252MBps, while the OCZ Vector clocked in at 495MBps and the Samsung 840 Pro scored 481MBps.
The 4K read/write tests ascertain the performance of an SSD or HDD when reading and writing small chunks of data. These small read/writes are vital to the everyday performance of a storage solution. The "64 Threads" test in AS-SSD means that the benchmark program spins off 64 separate 4K read/write tasks. This stretches the controller's ability to manage such workloads, but also provides a more realistic performance metric – an operating system is constantly reading and writing data to multiple services and programs simultaneously. The Intel 335 lagged behind the OCZ and Samsung drives at 203MBps read and 214MBps write. The OCZ Vector logged read/write speeds of 359MBps and 304MBps, with the 840 Pro at 381MBps read, 299MBps write.
The random read/write performance data from SiSoft Sandra that we also quote is a measure of a drive's sustained performance when reading and writing a contiguous block of information to a randomly chosen location. These metrics are important because they collectively measure the different types of storage tasks an SSD or HDD performs, even if they don't represent user workloads.
SiSoft Sandra again shows the Intel 335 competing well in read performance (485MBps, while the OCZ Vector and Samsung 840 Pro both tie at 530MBps). Write performance is the drive's weak spot – the Intel 335's SF-2281 controller turned in a 225MBps in random write performance. That's less than half the OCZ Vector's 509MBps random write, or the Samsung 840 Pro's 507MBps.
Finally, there's PCMark 7, which is a different type of test. The benchmark uses real storage workloads created by recording traces of hard drive activity when playing games, loading music or video, or copying files. These traces are used to measure the performance of storage products in comprehensive real-world scenarios.
The difference between SSDs in PCMark 7 tends to be much smaller than what we see in other synthetic tests. The Intel 335 scored a 5214, compared to a 5419 for the OCZ Vector and a 5588 for the Samsung 840 Pro. The gap between the Intel SSD 335 and the other drives is roughly 7 per cent.
Right now, the Intel 335 Series 180GB is selling for around £140, which is about in line with the competition such as the Samsung 840 Pro (which might be more expensive, but it is a 256GB model).
The OCZ and Samsung options, however, are significantly faster than the Intel 335 Series. The SF-2281 controller has migrated to budget SSDs for a reason; it was cutting edge when it debuted in 2011, but its performance has been surpassed by other products.
That doesn't mean the Intel 335 is devoid of strong points. Intel has over-provisioned the drive by about 6.7 per cent, which is fairly high for consumer hardware. The company has a reputation for high quality NAND flash, and the included SSD toolbox software interfaces well with Windows and can auto-optimise an OS installation to run on solid state storage as well as manually triggering the TRIM command.
When push comes to shove, however, the Intel 335 Series 180GB SSD is in a bit of a no-man's land. There are budget drives, like Samsung's 840, that offer a lower cost per GB – and there are better performing drives for around the same cost per GB. If you can grab one of the 180GB or 240GB drives on sale, or if you're fond of Intel-branded products, then the Series 335 180GB SSD is a good option. Other buyers will find newer hardware a better deal.