MaximumPC 2004 06

36 MAXIMUM PC JUNE 2004

Is Serial ATA Faster

Than SCSI?

vibration controls for rack-mounted

the hard drive performance crown?

To see how ATA stacks up against SCSI

we gathered together the best of the best:

a 74GB 10,000rpm SATA Raptor from

Western Digital to defend the ATA title,

and Maxtor’s record-breaking Atlas 10K

Ultra 320 SCSI drive to represent its ilk.

And for kicks, we threw in a Maxtor Atlas

15K Ultra 320 SCSI drive as well, because

15K drives are fun to test and represent

the pinnacle of hard drive performance.

It should be noted that while the two 10K

drives sport capacities of 74GB and 73GB,

respectively, the 15K SCSI drive has a

capacity of just 18GB, given its intended

use in a server environment (smaller

drives are preferred because there’s less

data to replace if a failure occurs).

Testing consisted of Simplisoft’s HD

Tach 2.61 , which tests sequential read

speed, write speed, random access time,

connected to an Adaptec 29320A-R Ultra

320 controller, and the Western Digital

SATA drive was connected to our test

system’s onboard SATA controller, care of

the ICH5 south bridge chipset on an Intel

865GBF motherboard.

The results: Going into this test, we

thought Western Digital’s 10K Raptor

would hold its own; instead it actu-

ally dominated. In short, the 10K Raptor

handed the 10K Atlas its SCSI ass on a

platter. For some strange reason, the Atlas

laid down benchmark scores equivalent

to those of a high-end 7,200rpm SATA

drive. Although the Atlas’ seek times

were a smidge better than the Raptor’s,

the latter’s average read speed of 62MB/s

completely outpaced the Atlas’ meager

46MB/sec average. Point, set, and match

Perhaps the most surprising result,

however, was that the 10K Raptor scored

higher average sequential read speeds

across its platters than even the 15K

Maxtor drive. The fact is, these high-veloc-

ity SCSI drives aren’t made for sequential

transfers, as their high rotational velocities

are meant to provide enormous benefits

in multi-user environments with heavy

random access workloads. In random

access testing, the 15K SCSI drive hand-

ily outperformed the 10K drives. If you

subtract the standard 2ms of latency—the

time it takes the drive to pinpoint a spe-

cific sector on the platter—from the 15K’s

access time of 5.5ms, you end up with a

random access time of 3.5ms. That is fast

access, for sure.

Maxtor’s Atlas 10K is the fastest 10K SCSI drive

around, so we pitted it against the fastest 10K

ATA drive in a race “for pinks.” It lost.



EEXPERIMENTS WITHXPERIMENTS WITH

At the top of the hard drive food

chain sits the Maxtor Atlas 15K.

Hopefully ATA drives will evolve to

reach its unbelievable seek times.

HARD DRIVE

PERFORMANCE

10K ATA RAPTOR^

(74GB)

10K SCSI ATLAS^

(73GB)

15K SCSI ATLAS

(18GB)

HD TACH

Average read speed (MB/sec) 61.7 46.8 55.1

Average write speed (MB/sec) 36.1 34.3 41

Burst speed (MB/sec) 111 97 100

Random access time (ms) 7. 9 7. 2 5.5

Best scores are bolded.

Doesn’t this 10K Raptor look hungry?

And that’s after it ate a couple of SCSI drives for lunch!