SSDs are fast, but large capacities are expensive. Hard drives are way more affordable at large capacities, but very slow. You just can’t win, right? More and more, the solution is appearing to be a hybrid storage device, using a smaller SSD as a cache for a much larger hard drive. Brian reviewed one such solution, the Seagate Momentus XT 750GB hybrid drive, and found it to be an excellent addition to his everyday laptop computing. Today’s review focuses on the OCZ RevoDrive Hybrid, which is a solution for desktop computer users.
The RevoDrive Hybrid takes a 5400RPM 1TB Toshiba 2.5″ hard drive (which isn’t fast at all) and straps it on to a 100GB RevoDrive 3 (which is amazingly fast). The hard drive is mounted on a daughter card, and the whole thing looks very similar to a RevoDrive X2. Due to the height of the hard drive, the RevoDrive Hybrid occupies its own slot plus a small amount of the slot next to it. It’s fairly safe to say you won’t be able to put a full-length card in the slot below this SSD, though cards of shorter height or length might fit.
- Capacity: 1TB
- Cache: 100GB
- Interface: PCI Express 2.0 x4
- Read speed: up to 910MB/s
- Write speed: up to 810MB/s
- Max random write 4K: 120,000 IOPS
- Avg write: 65,000 IOPS
- Dimensions: 167.64 (l) x 98.42 (w) x 22.15mm (h)
- Weight: 289g
- Power: 8.1W idle, 10W active
- 3-year warranty
The SSD portion of the RevoDrive Hybrid uses 50% overprovisioning, meaning 50GB of the 100GB is reserved for rotating in and out of service as bits in the active portion of the cache are marked as no longer needed. (swapping with the “active” portion of the cache). This wear leveling helps minimize write amplifications allowing performance to remain steady and extending the useful life of the SSD portion of the RevoDrive Hybrid.
The RevoDrive Hybrid requires the included DataPlex software for cache management. A copy of recently and/or frequently used data is stored on the “hot” (SSD) portion of the RevoDrive Hybrid, while “cold” data is stored only on the hard drive. Interestingly, the entire file does not have to be cached on the SSD. File- and block-level caching are used by DataPlex, meaning huge files don’t have to be entirely copied to the SSD; only the active pieces of those files need to be copied.
It’s some pretty cool stuff, and I really like the way it works—with one caveat. The DataPlex software currently requires the RevoDrive Hybrid to be the primary storage device. This means in order for the software to work, you must have Windows installed on the RevoDrive Hybrid for the caching software to operate properly. In my opinion this is a pretty severe limitation that limits its viability. If you already have an existing installation of Windows, you’ll have to migrate it to the RevoDrive Hybrid or do a complete reinstall to see the benefit of the DataPlex software. A representative from the developer, NVELO, stated the company intends to remove this limitation in a future software revision, though the representative didn’t know exactly when this will happen. Fortunately there is a workaround of sorts: the DataPlex software isn’t concerned with partitions; it views the entire hard drive when caching. Using a smaller partition for Windows and a larger one for data works, and it works very well (this is how the review unit was configured for testing).
The RevoDrive Hybrid was tested before and after the Dataplex software was installed, to show the benefit of the SSD and caching software. For comparison purposes, the results for a RevoDrive 3 240GB, and a standard 7200RPM hard drive are included. What should be expected is uncached performance just below the 7200RPM hard drive (the RevoDrive Hybrid’s drive spins at 5400RPM), and cached performance closer to a RevoDrive Hybrid.
Atto Disk Benchmark shows off the speeds a storage device is capable of. Thanks to some highly compressible data, Atto shows off a best-case scenario for SSDs. The RevoDrive Hybrid is no exception. Read speeds are right up there with the RevoDrive 3, and while the write speeds aren’t quite as fast, they are significantly faster than a regular hard drive.
AS-SSD simulates a heavy workload test for devices and, as its name implies, is primarily targeted at SSDs. Data written to the storage devices is uncompressible, providing a worst-case scenario for writing to the drive. Tests involve sequential and random reads and writes. This unforgiving benchmark shows a huge improvement in 4K read/write and sequential read testing, virtually matching the RevoDrive 3. Sequential writes, and the heavily threaded 4K tests show impressive gains as well.
CrystalDiskMark measures the read/write speed for storage devices using a series of sequential and random tests of various sizes. Read performance is excellent, nearly equal to the RevoDrive 3. Write performance isn’t quite as good—in fact it is about halved, but it is still significantly better than a hard drive by itself.
Part of the PCMark Vantage benchmark, the storage component evaluates the performance of hard drives and SSDs. Tests include a Windows Defender scan; data streaming performance in Alan Wake; image importing to Windows Photo Gallery; Windows Vista Ultimate startup time; video editing using Windows Movie Maker; video playback, streaming, and recording in Windows Media Center; adding music to Windows Media Player; and application load times for Microsoft Word 2007, Adobe Photoshop CS2, Internet Explorer 7, and Outlook 2007.
Moving towards real application performance, there’s a clear benefit to the RevoDrive Hybrid. The applications that comprise the PCMark Vantage disk test all benefit greatly from the DataPlex caching software. In fact, the speed gains from caching are anywhere from 6 to 67 times greater than those of a regular hard drive.
EasyBCD is used to force Windows to a boot selection screen to allow for a consistent starting point. The time is stopped when the Windows finishes loading and the “ready” cursor is presented (the “busy circle” disappears from the arrow icon).
The RevoDrive Hybrid doesn’t only benefit programs and data while Windows is running; the boot files themselves are cached as well. This leads to boot times half that of a regular hard drive.
Pricing & Recommendation
During regular usage, the RevoDrive Hybrid never really seemed to slow to hard drive speeds. The DataPlex software caches data very quickly and appears to rotate the cold data off quickly as well. In fact, performance began to improve immediately after the reboot required by the DataPlex software installation, and never slowed down after that. Quite honestly, the everyday performance difference between the RevoDrive Hybrid and the RevoDrive 3 is practically indistinguishable. For practical purposes, you can consider this to be a drive that has 1TB capacity but is nearly as fast as an SSD.
The OCZ RevoDrive Hybrid sells for $329.99 on Newegg before rebates. While not exactly cheap, the combination of performance and capacity are really hard to beat—it’s larger than any other consumer SSD, faster than any hard drive, and cheaper than SSDs with half the storage. In fact, the cheapest 512GB SSD that can be easily found costs nearly $300 more and isn’t nearly as fast as the cached access speed of the RevoDrive Hybrid. It’s a killer combination, to be sure.
That being said, factoring in the current boot drive requirement does temper things a bit. After all, it is a limitation introduced by the DataPlex software, though a workaround of sorts exists. The software itself is great, and really is what makes the RevoDrive Hybrid stand apart. It just comes with a limitation that doesn’t make a whole lot of sense. True, a tech support representative says the limitation will be removed in a future software revision, but a recommendation cannot be based on future featues. If you can live with the current limitations, the OCZ RevoDrive Hybrid is an awesome product and comes highly recommended. We’d love to give it our Golden Fedora, but as it stands we’re still proud to award the OCZ RevoDrive Hybrid our Silver “Outstanding Product” award for excellence.