Sourcing High-Speed Storage for Mac Pro 4K Editors

Other Examples

During this analysis and research, I recalled my review of the HP Z840, which included performance tests on three types of drives, including the Z Turbo SSD G2 drive, which uses the same PCI technology as the Mac Pro. I also benchmarked a SATA-based data SSD drive, and a traditional hard disk drive.

You can see the Read/Write comparison in Table 1 (below) using the ATTO Disk Benchmark, which is a different test than the Blackmagic Design Disk Speed Test, so don’t compare the result, just the gist. The PCI-based Turbo SSD G2 drives are much, much faster than the SATA-based SSD drive, though both types totally outclass traditional HDD technology.

Table 1. Different SSD speeds on the HP Z840.

The bottom line is that while you might be able to find a faster external SSD drive than the Transcend unit (which has a 4.5 Amazon rating with 111 customer reviews, by the way), a single SATA drive won’t come close to the performance delivered by the PCI connection. So what are your alternatives?

RAID to the Rescue

When one SATA-based disk can’t deliver the necessary performance, you can always try a RAID configuration, which stands for Redundant Array of Inexpensive (or Independent) disks. While RAID arrays of traditional drives have been around for years, you can also create RAIDs with SSD drives. Of course, traditional drives are much cheaper, and you can control performance by adding drives to the array.

As you probably know, there are multiple RAID configurations, including RAID 0, which is the fastest but least secure. That’s because the data is spread over all the drives in the array while writing, so losing either drive, or any single drive in a RAID array greater than 2 drives, means total loss of data. To test RAID 0 performance with traditional drives, I purchased a Mercury Elite Pro Dual external Thunderbolt/USB 3.0 drive from Other World Computing, which has two 2TB drives and claims 442 MB/s sustained write performance.

The drive cost $439, so the total cost per TB was around $110, compared to $565 for the SSD drive. Of course, you should also build in the cost of slower, more secure backup for a RAID 0 configured system, because any single drive failure is totally catastrophic. Seagate sells a 4TB external drive for $117.95, boosting the cost per GB up to about $140.

How did the drive perform? Figure 4 (below) tells the tale. To save you a trip back to Figure 2, the Transcend SSD wrote at 296.6 MB/sec, which was slightly slower than the Elite Pro Dual, and read at 385 MB/sec, which was slightly faster. In the 4K project I was working with, both disks were fast enough to serve as the project disks, with cache files and previews stored on the Mac’s internal SSD. In that configuration, Premiere Pro was able to render the temp files and playback the video at full frame rate to the aptly named HP Dreamcolor Z32x 4K monitor.

Figure 4. Performance of a 2-disk traditional HDD system using RAID 0.

For faster performance, you can buy or build your own SSD-based RAID array. For an interesting and prescient read on that topic from June 2014, check out the PC World article Feed Your Greed for Speed by Installing SSDs in RAID 0.

I couldn’t find any inexpensive SSD-based external RAID systems with Thunderbolt/USB 3.0 connectors for sale when I wrote this article, but I’m sure they are out there, with more coming. In theory, most external enclosures for traditional drives should handle SSD drives, but I didn’t see a lot of comments on B&H, Amazon, or Other World Computing indicating that buyers had done this, and I sure wouldn’t buy one without checking with the manufacturer first.

What are the takeaways? Don’t expect external SSD drives to come close to the performance of internal drives on your Mac Pro (or most computers). Turn to RAID with either traditional or SSD drives for lower cost per GB (traditional) or greater speed (SSD).

Finally, if you haven’t bought the Mac Pro yet, note that some vendors, like HP, sell PCI-based cards with up to 2 TB of SSD memory each (the HP Z Turbo Drive Quad Pro), so you can put two or more in a single workstation for 4 TB of internal PCI-based SSD storage that should be just as fast as the Mac Pro, or faster. HP workstations like the Z840 also contain internal drive bays that you can install SSD drives into and configure into a RAID array, which was the focus of the aforementioned Feed Your Greed for Speed PC World story. While you lose the small form factor and portability of the Mac Pro, you can make that up by needing fewer external enclosures. I know, I know, it’s heresy to think about using anything other than a Mac, but for 4K producers who need capacious storage, it’s definitely worth considering.