The 750 uses 20nm NAND from Intel and Micron — the two companies have announced their own 3D NAND efforts, but that technology is still under development. These new drives bring two new features to the client side — NVMe support and the SFF-8639 connection bracket. Here, a bit of explanation may be in order. NVMe (Non-Volatile Memory, the “e” stands for express) is a communication standard that replaces AHCI and is designed explicitly for solid state drives as opposed to being meant primarily for spinning discs. The performance benefits of NVMe are something that we’ve covered before; the interface has a number of improvements that will boost drive performance in the long run.
The other new feature of the 750 family is the SFF-8639 adapter hooked up to a 2.5-inch SSD. Why an adapter? Because the SATA Express standard doesn’t offer enough bandwidth. SATA Express tops out at two lanes of PCIe, and while that’s still an improvement over the SATA 6G standard, it’s not enough for truly high-end SATA drives.
The SFF-8639 connector bridges the gap between SATA Express and PCI-Express drives with an x4 connector or above. It offers four lanes of PCIe connectivity to drives in a standard 2.5-inch form factor, and is expected to be popular in desktops as a high-end interface going forward. Your motherboard will still need to support the SATA Express standard in order to use the new 4GBps solution. If the motherboard in question backhauls the connection over PCIe 2.0 instead of 3.0, then you’re limited to half speed — 2GBps, not 4GBps.
How’s the new drive perform?
Anandtech has a comprehensive review of the new SSDs performance in client workloads and the results are truly impressive. Performance between Intel’s 1.2TB SSD 750 (that’s the full PCIe card version) and the Samsung SM951, which uses the older AHCI standard instead of NVMe, was quite close overall, with the Intel drive offering significantly better performance in some areas (typically write performance and some latency tests) while Samsung took the lead in others. Tellingly, however, the Intel and Samsung drives were both often 2-3x faster than the fastest desktop-class hardware currently available, like the Samsung 850 Pro. |
| Latency is one area where the Intel 750 shines |
These gains demonstrate how faster interfaces can still drive higher-performing SSDs, even when NAND flash itself isn’t getting any faster — if anything, the advent of TLC (triple-level cells) and lower process nodes, which require higher amounts of ECC, may have made NAND slightly slower. Memory controller and bandwidth improvements still have the ability to yield great gains.
That said, support for the SFF-8639 connector and SATA Express is all quite early. Right now, the only way to get full PCIe 3.0 bandwidth is to drop a PCIe card into a slot normally reserved for a graphics processor. This could limit future scalability, unless you buy a Haswell-E system, which offers 40 lanes of PCIe 3.0. These features should become more standard in future platforms from Intel and AMD, though neither company has offered a hard and fast roadmap for future integration.
The other thing to be aware of is that while current top-end SSDs are much faster than the drives from 2010-2011, and future drives promise to be 2-3x faster than the mainstream products of today, there’s a definite diminishing marginal return to adding higher-end storage. The great benefit of SSDs — and to be clear, a modest modern SSD is much faster than a hard drive — feels like a huge improvement, because it accelerates many common tasks by a factor of 10-100x compared to a spinning disk. If you’ve ever run a virus scan and played a game simultaneously, you’re familiar with how something as simple as a background file-scanning process can send performance cratering. Thanks to SSDs, that’s not an issue.
Once you move from HDDs to SSDs, the relative difference drops dramatically. Slashing system copy times from 8 minutes to 2 minutes is still a huge gain — but it doesn’t feel the same as cutting them from, say, 32 minutes to eight. Drives are going to continue to accelerate, and those of you who work with huge datasets or copy a great deal of information will absolutely benefit, but the gains are going to be less visible if you aren’t a relatively heavy user to start with.
Your VB Kid
Psypher
No comments:
Post a Comment