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Quantum Atlas V QM336700XC-LW

  February 15, 2000 Author: Eugene Ra  
Evaluation unit provided by Quantum Corp.

Last year, we witnessed the surprising resurgence of Quantum's Atlas drive series. The Atlas IV's release catapulted Quantum to the top of the performance charts. Further, the release of a 10,000 rpm drive based on the same technology, the Atlas 10k, allowed the company to make quite a splash in high-end markets. It's now one year later, time again to examine a new crop of SCSI drives and their performance. Quantum has followed up its best-of-class Atlas IV with, predictably, the Atlas V.

The 7200rpm Atlas V packs 9.1 gigs of data onto a single platter, doubling the areal density of its predecessor. 9.1 gigs/platter is very high indeed for a SCSI drive. The flagship model's 4 platters yield a capacity of 36.7 gigs. Quantum has shaved an additional bit off of the Atlas IV's seek time, specifying the Atlas V at 6.3 milliseconds. Cache has been doubled, this time weighing in at four megs. A 5-year warranty backs the drive.

This drive represent's Quantum's second generation unit to feature Ultra160/m, operation.'s current testbed features an Adaptec AHA-2940U2W, a card that maxes out at an 80 meg/sec transfer rate. Though the drive features a 160 meg/sec interface, the actual platter-to-buffer transfer rate tops out at a specified 29 megs a second, well within the limits of Ultra2 SCSI. At the time of this writing, we're planning to deploy a new testbed shortly which will feature a more up-to-date Ultra160m SCSI host adapter as well as a new suite of benchmarks. The figures that follow are the result of our testing methodology as of mid-February 2000.

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As the first of its generation, the Atlas V currently can be contrasted only against last year's drives. Compared to the Atlas IV,'s current 7200rpm SCSI champion, the Atlas V shows an improvement in both measured access times and measured transfer rates. Accesses clocked in about 7% faster, registering an average of 10.7 milliseconds. And, as one would expect, the Atlas V's vast increase in areal density results in a transfer rate significantly higher, 37%, than its predecessor.

WinBench 99's higher level tests show marked difference between the two disks. Scores from the Business Disk WinMark run under Windows 95 place the Atlas V 17% head of its predecessor. The High-End Disk Winmark yielded an even greater 19% improvement. In Windows NT, the performance gap between the units shrank to 9% according to Business tests. The gap in the high-end test, however, increased to a substantial 21%.

Due to its high-sensitivity to improved sequential transfer rates, ThreadMark 2.0 displays massive performance increases when comparing the two Atlas drives. Here the fifth-generation unit blasts past the fourth-generation by margins of 46% and 44% respectively in Windows 95 and Windows NT.

The Atlas V's noise-levels are commendable. No perceptible idle noise can be heard over our testbed's power-supply fan. When thrashing, the drives seeks are certainly audible (SCSI drives still haven't reached the muted levels of their ATA counterparts), yet nowhere near the drives of old. The disk runs warm to the touch; though it may need active cooling in a smaller, cramped case, it can run without such measures in more roomy configurations.

The Safe Buy Award

Simply put, this designation means we'd purchase this product without regret. Sure, there may be a slightly better, slightly faster, and/or slightly less-expensive model from a competitor, but you can't go wrong with this particular unit. This award is applicable, of course, to all units at the top of their class, but also applies to units that, though not quite best-of-class, provide a strong showing nonetheless.In conclusion, the Quantum Atlas V represents a competent improvement over its predecessor. Improved scores across the board combined with heat and noise levels no worse than the Atlas IV allow it to displace the latter drive as the current 7200rpm SCSI leaderboard champ. The Atlas V faces some interesting competition in the near future, however, in Seagate's Barracuda 18XL. Though its flagship model features only 18 gigs of space (the 10k rpm Cheetah seems to have been phased in as the manufacturer's mainstream offering, thus usurping "current" capacity levels), the newest Barracuda uses smaller-diameter platters to shave a bit off of its specified seek times. Can the Atlas V stave off the performance improvements that the Barracuda 18XL promises? We look forward to finding out!

Quantum Atlas V QM336700XC-LW
Estimated Price: $675
Also Available: QM318300XC-SW (18.3 GB); QM319100XC-SW (9.1 GV)
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* Note: Threadmark 2.0 test results are the average of five trials.
WinBench99 test results are the average of three trials.


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