The SPU Revolution

Netcell currently offers two products in its Revolution family of SPUs: NC5000 and NC3000. Also, a few partner companies and Netcell offer SPU cards that contain Revolution SPUs. (See the “SPU Products Compared” sidebar in this article for additional information.)

Revolution SPUs provide benefits to almost any computer user, from high-end home users to professionals creating data-intensive content. To receive the most benefit from an SPU, though, you’ll need at least three hard drives.

The Revolution SPUs make use of a 64-bit data path that can move up to 800MBps of data through a chip. Revolution handles almost all aspects of data management, freeing the CPU to perform other tasks.

It’s tempting to think of the Revolution SPU as a RAID controller. Netcell’s SPU does use RAID 3 technology, and both types of products provide some sort of protection against hard drive failures. Revolution, however, offers more flexibility than RAID controllers and some unique features such as the easy addition of multiple hard drives and automatic backups.

Revolution also provides several advantages over software-based RAID controllers, including one particularly significant benefit: The SPU handles all of the storage-related processing tasks, freeing the CPU for other tasks. With software-based RAID, the CPU must handle the RAID software’s requests in addition to all of its other tasks.

SPUs At Work

The SPU serves three primary functions: It maximizes performance, increases storage capacity, and protects stored data.

Performance. An SPU boosts your system’s performance by automatically spreading data among the drives in your multiple hard drive configuration. The SPU also attempts to predict what types of files you’ll need based on the type of work you’re doing. With the predicted files located on the hard drive and waiting for the user to access them, the SPU can quickly load them when required, improving overall performance. The SPU works especially well with large files, providing fast file transfer and loading, making it an excellent option for those who commonly use video and audio files. (Netcell, however, says Revolution isn’t as practical for users who deal mostly with small files.)

With larger and larger media files in use, hard drives need to store data as efficiently as possible. The drive should store data that you need to access quickly, for example, near the edges of the platter. The drive should store data that you rarely use near the middle. Tracking the locations of each file and of the best place to store each type of file is a complex process, but an SPU performs the calculations needed to best store the files without taxing the CPU.

An SPU also maximizes performance in that it lets you keep working in the event of a hard drive failure. If one of your drives crashes, the SPU skips the failed hard drive and leans more heavily on the remaining drives in your array until you get the problem drive replaced or fixed.

Storage capacity. It’s easy to add additional hard drives with an SPU, which of course lets you increase your storage capacity. You don’t have to install any drivers to make the new hard drives work, and the SPU treats all of them as one hard drive, making the process of organizing your files less complicated. Although the SPU system works most efficiently with hard drives that are the same brand and size, you can mix and match brands and sizes when connecting them to the SPU.

Data protection. The SPU makes automatic backup files of your data as you work without requiring any input from you. Best of all, the SPU completely handles the backup process, placing no additional strain on the CPU.

Because the backup process is automatic, you don’t have to worry about a hard drive failure. All of your data is protected; the SPU practically eliminates the danger of losing data because of a failed hard drive.

Third Brain?

Netcell refers to an SPU as the computer’s third brain. (Of course, Ageia calls its PhysX PPU the third brain, as well, so depending on your point of view, it might be your system’s fourth brain.)

But whereas a CPU is an all-purpose microprocessor that handles all kinds of tasks from all sorts of hardware and software systems, an SPU focuses on specialized operations dealing with storage, much like a GPU focuses on specialized tasks related to the graphics your system displays.

Nvidia CEO Jen-Hsun Huang is fond of saying such specialty processors eventually will grow powerful enough to make the CPU obsolete and lead to its end. In other words, Nvidia’s GPUs could eventually be powerful enough to handle the basic tasks of a CPU in addition to their specialty graphics processing tasks.

We prefer to think of the CPU as an efficient boss. The boss oversees the work being done and gives specialized tasks to each worker, matching them with the tasks that best suit them. By delegating tasks efficiently, the boss makes the most of everyone’s time and skills. As more and more specialty processors appear to take work away from the CPU, it can become a more efficient boss.

When the CPU is able to delegate processor-intensive storage tasks to an SPU, it can focus on such weighty matters as performing the calculations necessary for a game’s intricate AI subroutines. Such tasks are important enough that the CPU probably isn’t going anywhere for quite a while.

Of course, that could all change next week if a company develops some sort of AIPU.

by Kyle Schurman

The SPU Setup Although you can use different brands of hard drives in your multiple-drive setup with an SPU card, the overall system will only be as fast as the slowest of the hard drives. The system will run more smoothly if you use identical drives throughout the system. 1. Install a Netcell SPU card in an open expansion slot in your computer. 2. Connect your hard drives to the SPU card. You can connect three to five hard drives. 3. Create your storage array. Because Netcell tries to keep the overall process simple by using its QuickConfig technology, this should only take a few seconds. You then can run your Windows XP installation CD to configure the SPU to work with the OS; the Netcell SPU doesn’t require any special drivers (called Zero Drivers technology), and you can take advantage of the SPU’s features immediately after configuring it. Source: Netcell

SPU Products Compared Netcell currently offers two SPU chips: Revolution NC5000 and NC3000. SPU Chip Features NC3000 NC5000 Internal 64-bit data path Up to 3Gbps (400MBps) Up to 6Gbps (800MBps) Plug-and-play hard drive solutions Yes Yes ATA-100 channels 3 5 Integrated SDRAM controller 256MB 512MB PCI 2.2 interface 32 bit 33MHz or 66MHz 32 or 64 bit 33MHz or 66MHz Several companies are using Netcell’s Revolution SPU to create storage processing cards. (Netcell offers the SR5200 card, but it’s not a retail product.) SPU card features Revo SP-PCC5 Revo SP-PCC3 SPU3100PWB SPU5103PWB Company XFX XFX PNY PNY MSRP $249 to $299 $149 to $199 $175.99 $199.99 SPU chip NC5000 NC3000 NC3000 NC5000 Internal SATA ports 5 3 3 5 L2 drive cache 64MB 64MB 64MB 64MB PCI 2.2 interface 32 bit 66MHz 32 bit 66MHz 32 bit 33MHz/66MHz 32 bit 33MHz/66MHz Max drive transfer 600MBps 300MBps 150MBps 150MBps Compatibility Windows/Mac* Windows/Mac* Windows Windows *XFX offers a Macintosh version of both of its Revo cards: SP-MAC5 and SP-MAC3. For more information: Netcell SR5200 www.netcell.com/products.html PNY Technologies SR3100 or SR5103 www.pny.com/products/storage/ XFX Revo SP-PCC5 or SP-PCC3 www.xfxforce.com/web/product/listConfigurations.jspa?seriesId=66

Examining A Hard Drive Crash When running a system with a Netcell SPU, one of the biggest benefits is the SPU’s ability to let the system recover quickly and completely from a hard drive crash. Without an SPU, the system won’t recover completely, or possibly at all, from a failed hard drive. Source: Netcell

Data Migration Technology You can easily spread your existing hard drive data among multiple hard drives using the Data Migration technology built into Netcell’s SPUs. When you want to increase the capacity of your system’s storage, you could replace your existing hard drive with a newer, larger hard drive. But that solution would require copying all of your data and reinstalling your OS. By using an SPU card, you can add extra hard drives without hassle. The Data Migration technology behind the SPU makes the drives work together and automatically spreads your data across the multiple drives. You don’t need new drivers to make the hard drives work together, and you don’t have to reinstall the OS. Data Migration technology and the SPU card ensure that your multiple hard drives all work and look like one hard drive--with the combined storage capacity of all of the drives--to your OS. Source: Netcell

XOR Technology Netcell’s Revolution SPU makes use of an on-the-fly XceleratOR Engine, which lets it operate more quickly than a traditional RAID 5 card. Revolution builds upon RAID 0, RAID 1, and RAID 5 configurations by using XOR-based RAID 3. The different processes let the XOR Engine work more efficiently and faster in the read and write steps than a RAID 5 engine. The XOR Engine works behind the scenes to break data down into small blocks, known as words (shown in this diagram as A, B, C, and D). The words are then synchronously written to or read from all of the drives. A RAID 5 card, on the other hand, would use larger data blocks and write to or read from each drive sequentially, which takes longer than the XOR Engine’s process. Source: Netcell

Instant Crash Protection Figure 1: When a hard drive crashes in a computer without an SPU card, you lose your data and the ability to run the computer. Figure 2:But a computer using SPU technology and at least three hard drives gives you additional storage capacity and data protection. If one of the hard drives connected to the SPU card fails, the SPU detects the failure and immediately protects your data. You can also continually access the computer without performance loss. The Netcell SPU card provides many of the data protection benefits you’ll find with a RAID controller, but Netcell says its product significantly simplifies the process vs. installing the RAID controller. When a hard drive connected to a RAID controller fails, system and hard drive performance are reduced. Source: Netcell