February 18, 2002

Review: Seagate Cheetah X15 36LP SCSI drive

Author: JT Smith

- By Jeff Field -

When I reviewed the Seagate 10,000-RPM Cheetah 36XL SCSI drive last year, I was impressed. The drive was not very noisy, and performed well. More than six months later, I have another Seagate drive on my workbench, the "followup" to the 36XL, Seagate's 15,000-RPM X15 36LP. Seagate claims it has the "fastest data access in the industry."

The first thing I noticed when I powered up the X15 was the noise, or rather, lack of noise. The 10,000-RPM drives I tested from Seagate weren't noisy either, but somehow, even when increasing the spin of the drive by 50%, noise seems to have been reduced with the new drive, which is amazing. Even sitting out in the open on my test drive, I can only hear a low hum coming from the drive, sounds that could easily be masked by a case. This is impressive because I have been on a quest to make the quietest fast PC I can, and with drives like the 36LP, my task is much easier.

The packaging
As usual, Seagate has not only upgraded the speed of the drive, but also the mechanics and casing of the drive. The 36LP represents Seagate's latest design innovations in both of these areas. Seagate likes to have marketing names for all these technologies, some of which I have covered before, such as "SeaShell" and SAMS, although missing now is "SeaShield," which was focused on preventing the electronics on the bottom of the drive from being damaged.

SeaShell is Seagate's technology focused on reducing damage done to the drive from shocks. This is mostly to avoid damage in shipping and reduce the return rate. It was present on the Barracuda IV, which I have reviewed previously. The other technology is SAMS, also present on other drives I have reviewed, which compensates for the vibrations of multiple drives, so the drive "misses" less when reading. "Missing" forces the drive to make another entire rotation to read the data it was trying to get to. The drive also ships with Seagate's JIT, just-in-time, technology, which "minimizes actuator impact on power, vibration and acoustics." Judging by the lack of noise from this drive, I would say JIT is doing its job.

P4-2.0GHz Northwood CPU
256 Megs DDR RAM
Intel D845BG Motherboard
39160 SCSI Card
Leadtek WinFast GeForce3 TDH
WDC WD102BA IDE Boot/Swap Drive
Debian Unstable (3.0)
Linux Kernel 2.4.17
bonnie++ 1.02b, hdparm v4.5

Cheetah 36LP tested using a single empty 35-gigabyte ReiserFS partition.

bonnie++ results
Bonnie++ is a hard drive benchmark that tests the writing and reading
from both a single large file (such as that of a database) and many small files (like a proxy, or mail program). It is
useful for simulating the performance of such applications.

Bonnie++ results
Sequential Output
Drive Per-Character Block Rewrite
Cheetah 36LP 14161 K/sec, 66% CPU 45389 K/sec, 21% CPU 23909 K/sec, 07% CPU
Cheetah 36LW 9089 K/sec, 66% CPU 28760 K/sec, 17% CPU 16759 K/sec, 07% CPU
Sequential Input Random
Drive Per-Character Block Random
Cheetah 36LP 17831 K/sec, 77% CPU 57701 K/sec, 07% CPU 480.3 Seeks/sec, 0% CPU
Cheetah 36LW 11208 K/sec, 79% CPU 35971 K/sec, 09% CPU 303.3 Seeks/sec, 0% CPU
Sequential Create
Drive Create Read Delete
Cheetah 36LP 21312 /sec, 85% CPU none 20106/sec, 85% CPU
Cheetah 36LW 13119 /sec, 84% CPU none 14677/sec, 73% CPU
Random Create
Drive Create Read Delete
Cheetah 36LP 20656 /sec, 85% CPU none 18232/sec, 85% CPU
Cheetah 36LW 18503 /sec, 85% CPU none 15673/sec, 86% CPU

Here we see the Cheetah X15 36LP performs very well on the bonnie++ tests, beating the 36LW by a large margin in many tests, with notably large differences in block input/output and seeks/second. With such a wide margin it is easy to see why Seagate is advertising the X15 and the industry's fastest hard drive.

hdparm results
The hdparm tests give you the raw throughput of the device -- essentially, the best you can possibly hope for. Uncached is the buffered speed of the disk, without the use of the operating system cache. Cached results test the perform of the RAM and CPU more than they test the drive itself.

hdparm -t (Uncached) Results
Cheetah 36LP 57.66 MB/sec
Cheetah 36LW 36.57 MB/sec
hdparm -T (Cached) Results
Cheetah 36LP 328.21 MB/sec
Cheetah 36LW 297.67 MB/sec

Here again, we see the 36LP shine; it's getting very close to the advertised speed of "up to 69MB/second." This is really excellent performance, not that the 36LW is a slow drive, but the 36LP speeds right past it, making it the clear choice in a performance sensitive environment.

The X15 36LP is an excellent drive: quiet, and yet the fastest drive I have ever tested. The only thing that makes it hard to recommend is the price -- $470 on Pricewatch for the 36-gig version I tested and $270 for the 18-gig version. If you are in the market for a fast SCSI drive, I recommend the 36LP highly; it is a great drive. However, if you are the average user, or even most high-end users, you'll probably find a better deal in a less expensive IDE drive, even if the performance is less than the Cheetah. This drive is meant for the big leagues, and is priced accordingly. For those of you who do purchase one, however, I can safely say you will not regret it.


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