What and why?
Anandtech.com, a well-respected hardware technology site, describes SSDs as a must-have, game-changing upgrade:
"I don’t know how else to say this: it’s an order of magnitude faster than a hard drive. It’s the difference between a hang glider and the space shuttle; both will fly, it’s just that one takes you to space."A Solid State Drive does the same thing as a hard disk drive in your computer. However, they have no moving parts; they're made of the same flash memory used in USB thumb drives. This gives them a couple of advantages: they're generally faster, and specifically much faster at retrieving many small files. When a hard drive tries to retrieve many small files, its magnetic read/write head has to physically move to each file, which takes time. With no moving parts, an SSD can do this about 50 times faster. Yes, 50. It's a quantum leap in performance. The drawbacks, at present, are capacity and price.
History
Solid state drives first came into use in early netbooks (cheap ultraportable laptops) because they were lighter, more durable, and used less power than hard drives. They also improved boot times, though the SSDs of the time didn't have room to store much more than the operating system. SSD's didn't spread into other types of computers immediately, but over the past two years, capacity has increased and the technology has matured.
Issue 1: Stuttering
There have been some hurdles to overcome. When used to boot a Windows OS, some drives have suffered from "stuttering", where the computer freezes for several seconds periodically. The roots of this problem seem to lie in the circuitry that manages communication between all those flash memory chips and the rest of the computer. According to Anandtech, stuttering seems to have been overcome in drives using controllers made by Indilinx or Intel, rather than older controllers by JMicron or Samsung. Anandtech's most recent article lists several models with good controllers, and a previous article compares several older drives that are still being sold.
Issue 2: Performance fade
The new controllers are also on the road to addressing problems with performance degradation over time. This is a really complicated issue to describe, but Anandtech covers it. The remedy is either having a capability called TRIM built into all your hardware and software, or periodically running a refreshing tool; for some drives, neither is available.
Issue 3: Bricking
Another issue that I've heard discussed, largely in the user forums of resellers (like Newegg) and drive manufacturers (like Intel), is that the drives occasionally just quit working after weeks or even months of use and they can't be fixed. They are, in Internet parlance, "bricked", like an jailbroken iPhone. This problem is a little murkier, which doesn't give me confidence. It seems to be associated with previous-generation drives (for example, Intel's X25-M G1 as opposed to G2), though that could simply be a matter of how long they've been available for people to talk about them. It is also associated with firmware updates, for example, a bad one Intel relased to enable TRIM and then pulled.
The plan
The drive I'm looking at is the Intel X25-M G2. It currently costs about $260 and has 64GB capacity. That's enough to hold an installation of Windows 7 plus applications and user profiles for the life of the computer, though documents will have to be kept on a hard disk drive. It addresses the stuttering and performance degradation issues, and so far there are not too many complaints of bricking.
My current laptop was cheap when I bought it 3 1/2 years ago, and now strains under the burden of audio, video, and Web 2.0 applications. My hope is that with a multi-core processor (AMD Phenom II X4 or Athlon II X4 or Intel Core 2 Quad), Windows 7 (no way am I touching Vista), and an SSD, I'll have a computer that won't slow to a crawl after a few years of accumulated cruft.
I wonder if the stuttering and degradation could be corrected with periodic backup and reorg. Files get fragmented in any storage device and reshuffling them greatly improves access performance.
ReplyDeleteThe performance degradation is a well-understood problem that stems from the fact that flash memory can read smaller chunks of data than it can write. So the drive will put small files on small parts of fresh pages until there are no fresh pages left (though the disk is far from full). Then it has to start reading pages and re-writing them with partial new data.
ReplyDeleteThe stuttering thing is more mysterious. It's been blamed basically on bandwidth in the controllers. These are outrageously fast devices, and there's a lot of computational overhead involved in making them work efficiently, so the controllers are serious hardware. The read speeds of the better drives actually saturate the SATA II bus (3Gbit/sec), which is astonishing.