OWC sent me the DataDoubler (purple), so my MacBook Pro now has "paired storage": A hard disk drive and an SSD

Datacenter servers commonly store data on shared networked storage arrays, but the laptops and desktops used by individuals continue to rely on internal hard disk drives. Enterprise arrays employ a number of performance enhancements, including large RAM caches and fast flash storage, but end users are stuck with single disks. This is changing, however, as users increasingly deploy flash SSD for performance while retaining a hard disk as well for capacity. This is “paired storage”, and it’s a major trend.

Tiering and Pairing Storage

Tiered storage is commonly used in the enterprise server space. Storage pros deploy a few different categories of storage and assign them to servers as needed: Slower RAID-5 for capacity and faster 15k rpm mirrors or flash SSD for performance. Some systems now have the ability to actively move data on the fly between according to demand, often on a block-by-block basis.

Tiered storage makes sense in the enterprise because storage arrays are shared by multiple servers. But it was impractical to deploy multiple storage types in a desktop, and often impossible in a laptop. The typical client machine still has a single hard disk drive, often chosen for capacity rather than performance.

Avid gamers challenged the status quo, however, by deploying faster hard drives, multiple drive types, and even RAID storage. Drives like the 15k rpm Western Digital VelociRaptor and OCZ Vertex SSDs took this enthusiast market by storm, and the excitement about the massive performance offered by these devices is spilling over into other markets.

Today, high-end laptop and desktop buyers are rapidly adopting dual-drive strategies, pairing an SSD for booting and applications with a hard disk drive for capacity. PC makers are responding, offering built-to-order paired storage configurations in high-end machines like the Apple iMac.

Leave The Optical Drive At Home

A common aftermarket paired storage configuration replaces the optical drive with a hard disk drive (HDD) using a specialized bracket. This is especially common in the Apple world, with MacBook Pro users snapping up the MCE OptiBay and OWC DataDoubler and moving their DVD SuperDrives to external enclosures.

One reason for this shift is the lagging capacity of optical media. Today’s hard disk drives have up to 100 times the capacity of a DVD, and “ripped” media files are even more compact. A 1 TB hard disk drive can hold over a thousand hours of high-definition video and can serve double duty storing virtual machine disks, music, and other space hogs as well.

Another reason to skip the DVD drive is a shift in the distribution of software from optical disc to online download. Apple has rapidly moved to Internet-based distribution with their Mac App Store, and independent publishers commonly rely on digital downloads rather than box-and-disc distribution. Many users simply no longer need an optical drive.

Fitting an SSD in place of a DVD or Blu-Ray drive is something of a challenge, however. The Slim SATA connectors used by optical drives is mechanically incompatible with laptop hard disks (microSATA), as is the drive bay mounting screw locations.

Data Placement Difficulties

But mainstream operating systems like Microsoft Windows 7 and Apple Mac OS X are not inherently suited for paired storage. No desktop operating is able to make optimal use of an SSD and hard drive by dynamically placing data according to performance demands or frequency of access. They will not even combine the SSD and HDD into a single logical drive.

Instead, users must manually configure their storage, often placing most of their data on the SSD and moving data to the hard disk by hand. This wastes valuable flash capacity and limits the effectiveness of a paired storage configuration. But users are willing to sacrifice some price efficiency for the performance they get from the SSD.

Stephen’s Stance

Paired storage is a growing trend in the laptop computer market, with many high-end machines sporting both a SSD and hard disk drive. But it remains a game for the rich, adding many hundreds of dollars to the cost of a computer, and manually placing data is inefficient. It will be interesting to see if future operating systems bring better support for paired storage, and if it will reach into the server world.

© sfoskett for Stephen Foskett, Pack Rat, 2011. | What Is Paired Storage?
This post was categorized as Apple, Enterprise storage, Personal, Terabyte home, Virtual Storage. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.

Can you supercharge a Mac Mini?

Last week I reported my progress upgrading my Mac Mini’s RAM and hard drive to extract much more performance out of Apple’s little desktop. And indeed, adding a 7200 rpm high-performance laptop hard drive did make a noticeable difference in system responsiveness.

But a question came in via email asking, will Western Digital’s killer 10,000 rpm VelociRaptor SATA drive work in the Mac Mini? So inspired, I set out to find out just how far one can push a Mac Mini’s performance!

Pillars of Performance

As I noted in my last update, there are four keys to desktop system performance: CPU, RAM, storage, and graphics. The Mac Mini’s CPU is soldered in place and its graphics are integrated into the system chipset, so neither are upgradable. The best one can do on the CPU side is to order a built-to-order 2.26 GHz Mac Mini from Apple, adding $150 to the base Mac Mini price of $599.

Base Mac Mini: $599

2.26 GHz CPU upgrade: $150

Running total: $749

PC hackers commonly upgrade their systems’ performance by tweaking the system BIOS to overclock the CPU, memory, and system bus. But you can’t overclock a Mac Mini, or at least I haven’t found the secret yet.

More RAM always helps, but the Mini won’t accept more than 4 GB 8 GB of RAM. The graphics can also be improved slightly by installing more than 1 GB of RAM because the system will then use 256 MB of RAM as a frame buffer instead of 128 MB. Since we’re going to be opening the system anyway, we can save some money by upgrading the RAM ourselves. The Mac Mini uses 204-pin DDR3 SO-DIMMs rated at PC3-8500 (1066 MHz). A nice 4 GB matched set can be purchased from Amazon.com for $60.

4 GB RAM upgrade: $66

Running total: $815

Your Apple Mac Mini is now maximally configured, with the exception of storage.

Update: The 2009 Mac Minis can now accept 8 GB of RAM!

Killer Storage

The only remaining upgrade is storage. And here, the Mac Mini is amazingly adaptable. About 2/3 of the vertical space covered by that aluminum and plastic exterior consists of a black plastic cage containing the DVD SuperDrive, hard disk drive, and cooling fan and serving as a support for the BlueTooth and 802.11 wireless antennas. This is your target.

The Mac Mini’s storage subsystem is up to date, with two SATA channels supporting 3 Gbit speed and advanced capabilities like native command queueing (NCQ) even though the stock Mini’s hard drive lacks these features.

The hard drive sits in a cradle immediately under the optical drive, face-up in an open cavity over the motherboard. Although it ships with a slim 9.5 mm high hard disk, my ruler says that the Mac Mini cradle can accept a 12.5 mm z-height disk. This is interesting from a capacity standpoint, since some higher-GB drives are 12.5 mm 3-platter units, including the popular TravelStar 5k500 drive from Hitachi.

However, the Mini was designed to have an air gap between the hard disk and DVD drive, and a 12.5 mm drive will press against the optical unit, potentially causing heat problems. And a larger 2.5″ drive will not fit, including the 15 mm mechanism from the Western Digital VelociRaptor.

Therefore, any crazy disk drive dreams that also include leaving the Mini and its DVD drive in the original case are right out. All is not lost, however! Apple kindly included the MacBook Air’s Remote Disc support, so the Mini doesn’t need a DVD drive at all if you happen to have another Mac or PC handy. Removing the SuperDrive leaves room for up to two 2.5″ hard disks!

Without the SuperDrive in the way, a 2.5″ Western Digital VelociRaptor hard disk drive should fit just fine. Although it ships with a massive heat sink, the VelociRaptor isn’t as power-hungry or hot as you might imagine. It might be a good idea to apply some cooling fins or add an extra fan, but I’m betting the Mini wouldn’t have any trouble driving this 10,000 rpm drive once the SuperDrive is removed. So the WD VelociRaptor is a serious option for the Mac Mini.

Another killer performance option is a RAID-0 set of internal SATA drives. Although the Mini’s second SATA channel (normally used for the DVD drive) does not have the proper connectors or mounting supports for a hard disk drive, iFixit sells a DIY kit to connect a second hard drive. This kit, which includes two 500 GB 5400 rpm hard drives, sells for about what a single 300 GB VelociRaptor costs, and should provide similar performance using RAID-0 striping.

WD 300 GB VelociRaptor hard disk or iFixit dual-500 GB kit: $250

Running total: $1,065

Conclusion

So there you have it! For just over $1,000, you can have the baddest Apple Mac Mini possible. But for quite a bit less, I suspect that a 2.0 GHz/4 GB/7200 rpm disk combo would be nearly as fast.

One more thing: If you decide to use RAID-0 on your internal drives, you must use Time Machine to protect your data! A stripe set of disk drives poorly mounted in a tiny chassis without a properly-engineered cooling or power system is a recipe for disaster. Your disks will fail, and your data will be lost!

Note: Some of these links include affiliate codes that help pay for this blog. For example, buying an Amazon Kindle with this link sends a few bucks my way! But I don't write this blog to make money, and am happy to link to sites and stores that don't pay anything. I like Amazon and buy tons from them, but you're free to buy whatever and wherever you want.

© sfoskett for Stephen Foskett, Pack Rat, 2009. | How Far Can You Push a Mac Mini?
This post was categorized as Apple, Terabyte home. Each of my categories has its own feed if you'd like to filter out or focus on posts like this.