Test: How much better are solid-state drives over hard disks?

I have seen the future, and it is solid state. The solid-state disk (SSD) computing revolution has arrived, almost. Solid-state drives are, of course, like the flash drives in your camera, only bigger, and now, much faster. Devoid of moving parts, cool-running, quiet as a church mouse, energy-sipping and data crunching at light speed, these hard drives will be our medium for data storage for the foreseeable future.

We snagged a quartet of these mind-boggling wafers of goodness, and they gave us a fascinating peek into the future. Just how fast are they? We benchmarked them in a group of four, all lashed together in a single volume that uses teamwork to speed things up (known to geekdom as a RAID 0 array), and then we loaded up a singleton to see how it compares. Click on Continue Reading to see how they fared.



They're small. The four Intel X25-E SATA solid state drives we tested are actually 2.5-inch drives (each now selling for $848) adapted by Western Digital to fit into 3.5-inch drive cages. Surrounding the small and thin enclosures are heat sinks, hardly needed because these drives barely heat up at all.

They are completely silent. We loaded Windows XP onto an array of four of these drives, and the only drive noise we heard was the whine of the DVD as it offloaded its data onto the 4-SSD volume. Once the data was onto the drives, there was none of that mechanical grinding, clinking, humming and groaning that normally emanates from fast spinning drives. It's an eerie silence, but wonderfully serene.

They're fast. Intel's figured out how to get these NAND chips to access small files, a former weakness that was holding SSDs back. Using "Native Command Queuing" with a 10-channel flash controller, seek time is minimized, and the result is some lickety-split performance. It's almost as fast as RAM, but unlike RAM, that data permanently sticks to the solid-state disk, rather than going away when the PC is shut down as it does with RAM.

Read 'em and weep. Look at these numbers! TK per second for a single drive vs. TK for a SAS (serial-attached SCSI, the fastest) drive spinning at 15,000 rpm. And the clincher, TKMB/s when you strip four of the babies together in a RAID 0 array. Goodness gracious.

We tested the drives using four different benchmarks, and all the results were similar to these from the Passmark PerformanceTest (download a free 32-bit or 64-bit trial here to test your system — we used the 64-bit version).




graphic1-ssd-vs-15k.jpg
(Click each image for enlargement) The spinning drive almost keeps up with the SSD in sequential reading, but look how it gets manhandled with random seeks — it's 93.4% slower. Ouch.




graphic2-ssd-vs-ssd-array.jpg
When you gang up the SSDs in an array, they're substantially faster, especially the sequential reads, 202% faster than a single drive.




graphic3-15k-array-vs-ssd-array.jpg
We gave the 15,000 RPM spinning disk array a head start, striping together six of them against the four SSDs. They still got smoked, especially in random seeks.




But boot time isn't affected as much. Check out these numbers, where shutdown time was strangely longer with the solid-state drives.

Bootup time to first cursor:
SSD:1:22
15K: 1:34

Shutdown:
SSD: 00:28
15K: 00:11




They're still not perfect. While we didn't see any degradation in our four "single-level cell" (SLC) drives' performance after multiple tests, other reviewers have seen that problem in multi-level cell (MLC) devices such as Intel's 80GB and 160GB drives, saying that they slowed down as more data was written to them, and defragmentation utilities only made matters worse. But Intel's working on this problem, and recently released new firmware for those 80GB and 160GB SSDs that reportedly fixed the problem. Still, this is new tech, and not everything about it is perfect yet. Sounds like a good reason to wait awhile before jumping into the SSD game. Here's one last, and very big reason to wait:

They're crazy expensive. It's definitely not time to buy these suckers, oh no. Just watch and enjoy the tech for now and let the early adopters spend $1000 apiece for 64GB drives. That's roughly 4x-4.5x the price of already-pricey 15K SAS drives. Two years from now, many more drives will be solid-state, because prices will have plummeted to an affordable level, and those pesky fragmentation issues will be solved. Until then, rest assured that you've seen the future, and it's solid state.