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Cheap RAID Ravages WD Raptor

Full Throttle: 7,200 RPM RAID 0

This setup resembles the ultimate challenge for the WD1500 Raptor. Will two WD4000KD drives in RAID 0 outperform the Raptor in every benchmark?

State-of-the-Art: 10,000 RPM RAID 0

Although this scenario is by far the most expensive - it requires two WD Raptor drives - it certainly is the most desirable as well. Two 10,000 RPM Raptors in a RAID 0 setup should blow everything else away easily.


Performance Expectations

In theory, RAID 0 promises to be an ideal performance array, as the sequential transfer performance multiplies almost linearly with the number of drives added to the array. Files are distributed block by block across all drives, which allows the RAID controller to write data onto all drives almost simultaneously. Transfer performance measurably and noticeably increases for almost all application scenarios, though access times cannot be shortened. In real life, access times usually suffer from a marginal increase in RAID 0 setups. This is no reason for worry, as we're talking about half a millisecond, which is nothing you will ever notice.

The storage controller may in fact become a bottleneck if you set up a RAID array with multiple drives. PCI devices max out at 133 MB/s, which even two hard drives reach easily today. Serial ATA controllers that are part of a motherboard chipset usually provide much stronger backbones and typically don't limit RAID performance.

We measured up to 350 MB/s using four 10,000 RPM WD Raptor drives and Intel's ICH7 or ICH8 chipset components. This is an excellent result, as it almost matches the added throughput of four single drives. At the same time, Nvidia's nForce 680 chipset somehow showed a 110 MB/s bottleneck, which we still couldn't overcome. It shows that not every integrated controller is suitable of hosting a high-performance RAID 0, despite technically supporting it.

  • malveaux
    Great review. This is a very important issue for some people. For me, I don't like getting the most expensive new edge tech when I can get less expensive options. RAID is a very simple technology, but it happens to work better because like all things, more heads do better than one in a thinking contest.

    I would have been really impressed if you guys took 4 drives at 7200rpm and low sizes, like 80gig drives, and did a RAID 0 with 4 drives and compared that speed with them. The access time would have been the same, but for the cost, the read and write would have been retarded high and made it look silly.

    Then again, your electricity bill may be the difference in the cost, lol.