Saturday, February 26, 2011

SSD, (external) SATA and USB2

It's been a few weeks since the upgrade to SSD, and I was starting to be concerned about my external USB drives. I have two Iomega Prestige USB2 drives (one bought by my robot overlord employer, one bought for personal use). I am scared to death of single-drive data storage on laptops, because wrecking the drive not only kills your OS but also all your data. I like how in desktops and servers pretty much everyone I know tries to use multiple drives, and leaves the OS on its own. Under reasonable conditions (properly filtered power, nobody working the case over with a baseball bat, etc.) it would be extremely rare to lose more than one drive at a time.

With the laptop we don't have that luxury. Since we do all of our programming work with a centralized repository, a disk failure is not a catastrophe: whatever was checked into the repository is on a much stronger server that goes through a reasonable backups regime (I pray to God). If the work was not checked in, most of us run at least online backups, and some of us run a second backups job to an external drive (the reason the company bought me the first USB drive).

A side effect of the switch from a proper HDD to a SDD was less disk space available. I had little by little moved the Windows 7 libraries to external drives, which frees up space but makes it much slower to browse them or to run a media library. A while after the SSD switch I discovered (a year after I bought the damn thing!) that my machine has a built-in external SATA port, and that thanks to my port replicator, I had a second external SATA port available.

And a 160GB, 7200 RPM 2.5" drive sitting in a drawer since I switched to SSD. I thought hell, I can pick up an e-SATA enclosure on Amazon for a few bucks...

I was wrong, it is not that easy. Almost all enclosures I found can't get power through the SATA cable, instead you have to plugin either a power supply, or a Y-cable with two USB prongs. In other words, you are expected to surrender two USB ports to use them as dummy power ports.

A couple of days later a third party showed me a site that specializes in storage for laptops. They sell custom enclosures designed to fit into modular drive bays, so for example you can eject the DVD burner you rarely use and slide in a cage holding a SATA drive, which beats the hell out of connecting the drive with a USB2 enclosure.

The site also had a fascinating product: an external SATA cable that plugs straight into a drive. They sell this thing for $20 and they throw in a rubber bumper for the drive, which basically turns it into the simplest external drive enclosure I have ever seen. I bought one, and it arrived two days later. It took seconds to install.

Just for the hell of it, I decided to test the SSD (C:), the 7200 RPM drive (K:) that is now connected through external SATA, and the two USB2 1TB (E:. I:) drives. Here are the test runs with Crystal Disk Mark (I didn't care about the benchmark, all I wanted was to run the same thing against all four drives):

This is one of the 1TB USB2 drives:


This is the second 1TB USB2 drive:


Here's the 160GB 7200 RPM drive, now connected through external SATA, obviously faster than either of the two USB2 drives:


And yes, both USB2 drives are 7200 RPM SATA drives, and USB2 is murdering them.

And finally, here's the SSD:


Ouch. Now it is obvious I have two things I can do:

  1. Get a single-drive external SATA enclosure for one of the 1TB drives, retire the second one which sounds stupid even as I write this.
  2. Get an external SATA enclosure that allows me to use BOTH 1TB drives at the same time. I don't want a RAID enclosure. This allows me to use the second external SATA port that I have available, and much faster access to my two 1TB drives. I am going to upgrade Ivette's laptop to SSD, which means I can get her 320GB drive connected to her laptop with one of those $20 cables so her media files are not sitting on the machine. I almost considered confiscating that drive, but it is only 5400 RPM. 

What annoys me right now is that this "external" SATA standard seems to be half-assed. In this day and age, one would have expected that "external" connector standards deal consistently with power transmission. Either that, or the problem is that the cheap enclosure makers don't want to add the extra 30 cents worth of circuitry needed to make the damn thing feed itself off the cable. If a $20 cable can do this, the only way a $30 enclosure can't is because the manufacturer is trying to save on the cost of the cable.