Editors' Rating
Published: 24 Jun 2009
Solid state has presented us with a problem. It's not just capacity — it's that, for the first time in recent memory, there's a very real threat that even a single solid-state drive (SSD) can saturate the bus to which it's attached. Companies are therefore turning to PCI-E instead of SATA for SSD storage, among them Fusion-io. As well as boosting throughput, physical space is saved by avoiding the need for the physical hard drives, cables and interfaces required to create a RAID array that matches SSD speeds — not to mention the vastly reduced heat output.
Fusion-io is certainly the most high profile of the add-in-board SSD manufacturers attracting the likes of Steve Wozniak and plenty of venture capital investment. Unlike OCZ and Promise, Fusion's offerings are aimed squarely at the enterprise space, and this has paid dividends, with its technology ending up in HP's IO Accelerator and being given 'Server Proven' status by IBM.
They should be in the consumer space soon though, with a version catered towards gamers branded the Fusion-io ioXtreme PCIe. It's endorsed by the gaming celebrity whom gamers love to hate, Fatal1ty, but stands a very real chance of being the first Fatal1ty product that either isn't pointlessly branded, or isn't rubbish.
This technology doesn't come cheap, however. The entry price for the above 80GB gamer card upon launch is a somewhat painful $900 (~£543). There's also the flagship ioDrive Duo which sits on a PCI-E x8 interface, RAID 0s two ioDrives together, features capacities up to 640GB and will set you back around £6,000. There's a 1.28TB version coming later this year. We're talking very, very serious stuff.
Design & features
The 80GB Fusion-io ioDrive connects through PCI-E x4.
The card on the bench today is the original 80GB Fusion-io ioDrive (160GB and 320GB variants are also available), which connects over a PCI-E x4 connection, giving it a potential 1Gbps bandwidth in both directions between the card and the rest of the machine. It retails for around £2,000 which breaks down to about £25 per GB. Compare that to about £3.41 per GB for an 80GB Intel X25-E, or around £0.07 per GB for a 1.5TB Seagate hard drive, and it becomes apparent the ioDrive is for those with immensely specialist data needs.
It's a half-height card (supplied to us with a full-height bracket), with green, orange and red status LEDs on the back. These perform diagnostic duties: a solid green light means the device is attached to the system and the driver is loaded; a flashing green light says it's reading; a flashing orange light indicates that the device is writing; and a solid red means the driver is not loaded. If you're remotely administering a number of ioDrives, you can also turn on a 'beacon' that highlights all three lights at once to identify the ioDrive in question. There's also a set of pins available that can be wired to your chassis for hard drive activity.
Status lights tell you when the device is successfully connected to the OS, is reading or writing, or has an error.
Installation is as easy as pushing in the card and installing the drivers (and optional SNMP support, if you want) at least on Windows. Despite a number of attempts, CentOS just didn't want to play with us (likely due to a kernel/driver mismatch), so it was off to Ubuntu for Linux testing. Installing the supplied .debs and running modprobe as suggested in the instructions wasn't enough we also had to move the drivers into the current kernel directory under /lib64/modules/ and add the fio-driver module name to /etc/modules file. Although this may be an obvious step to Linux admins, its omission from the manual may give some users grief. It's worth noting that you cannot boot an OS off the card this is a storage device only.
The ioManager software looks pretty much identical on both Linux and Windows, although you can opt for command-line tools if you wish (a separate package in Linux, while in Windows they are copied to Program Files\Fusion-io\Utils during driver install). There's even a separate remote manager application if your cards are locked away in a server room and don't want physical access. The options are relatively sparse: you can update the firmware, low-level format the drive, and attach or detach the device from the OS. Firmware version, serial number, PCI details and lifetime physical read and write statistics are displayed.
The ioManager software is cross-platform and easy to use.
On Windows, the latest firmware is installed into the Program Files\Fusion-io\firmware folder when you install the latest drivers. Although this little tidbit is listed in the manual, we'd prefer a separate download to make it more obvious that there's a BIOS update available. For Ubuntu, it seems as if installing the supplied .deb does all the firmware work for you.
Low-level formatting gives three options: Maximum Capacity, Improved Write Performance and Maximum Performance. Maximum Capacity gives you 74.93GB of formatted space, Improved Write Performance gives 37.47GB, while Maximum Write Performance gives 22.48GB. So how does lower capacity translate to extra performance?
The ioDrive uses a lot of redundant writes and checks at the bit, die and chip level that confirm a successful write and ensure the data is safe for the most part this is overcome by using high-quality parts and intelligently programmed controllers. During heavy writing though, the controller sometimes can't keep up with the needed write-flush commands to save the data to the NAND in a timely fashion. The extra capacity supplied in the improved and maximum write modes is therefore used to spread the redundancy load across the NAND chips, minimising the chances of slow down while still including that safety factor.
So while a single user is unlikely to really punish the ioDrive write-wise in any mode, and should be happy with the Maximum Capacity setting, we should start to see benefits in harsh situations like a multi-user environment. Our supplier tells us that the card also ships with 25 percent more NAND chips than it needs to add extra redundancy and to cope with wear levelling a little better and uses higher quality, ECC grade-three NAND chips, whereas the consumer drives use significantly cheaper grade one. It's even got its own dedicated parity chip.
The ioDrive supplies grade-three NAND chips, with 25 per cent redundancy for extra wear levelling capability.
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