When hard drives with 40 GBytes per platter just appeared their capacity was limited by 80 GBytes, i.e. only two platters could be used. However, at present, according to IBM, a standard system case is able to house up to 4 platters, thus providing 160 GBytes. But due to some reasons the maximum size of discs rotating at 7200 rpm is currently equal to 120 GBytes. And these giants are going to be tested today. Western Digital and IBM approached differently these figures. Western Digital increased both size (80-100-120 GBytes) and density gradually (taking into account that the WD800BB and WD1000BB had three platters we get 27-33-40 GBytes per platter). IBM jumped from 20 GBytes per platter directly to 40 GBytes per platter with the respective increase in capacity. Let's take a closer look at the participants.

Western Digital

WD1200BB
WD1200BB

The difference is in the marking only. But let us look at the insides.

WD1200BB	WD1200JB

Well, now we can see that the cache memory chips are different.

WD1200BB	WD1200JB

Pop in here and you will see that the buffer of the WD1200JB is really 8 MBytes :)

IBM

IBM DeskStar 120GXP

The disc looks like its predecessors of the 60GXP series. One of the most considerable changes inside is Antiferromagnetically coupled media (AFC). A thin layer of Ru (just 3 atoms) is sprayed between two layers. As a result the layers magnetize in different directions which allows writing data much denser (up to 100 GBytes per inch squared which makes possible to create hard drives of 400 GBytes of a standard form-factor). Here you can learn about this technology in detail.

Besides, the new model has a different onboard processor, cache control system and head positioning system. A load-unload ramp and ceramic balls in the spindle bearings are used to increase reliability. Of course, other company's technologies are also integrated - Drive Fitness Test (DFT), Temperature Monitoring, TrueTrak Servo and No-ID Sector Formatting system.

Here are the specifications of the drives.

	Western Digital Caviar WD1200BB	Western Digital Caviar WD1200JB	IBM 120GXP IC35L120AVVA07/ IC35L100AVVA07/ IC35L080AVVA07/ IC35L060AVVA07/ IC35L040AVVA07/ IC35L020AVVA07
Size	120 GBytes	120 GBytes	123.52/ 102.93/ 82.34/ 61.49/ 41.17/ 20.57 GBytes
Spindle speed	7200 RPM	7200 RPM	7200 RPM
Buffer size	2 MBytes	8 MBytes	2 MBytes
Heads	6	6	6/5/4/3/2/1
Platters	3	3	3/3/2/2/1/1
Latency	4.2 ms	4.2 ms	4.17 ms
Average search time in reading	8.9 ms	8.9 ms	8.5 ms
Average track-to-track search time	2.0 ms	1.2 ms	2.0 ms
Average full track search time in reading	21.0 ms	21.0 ms	15.0 ms

As you can see, the IBM is leading in characteristics, except a buffer size of the JB model.

Tests

The changes in our testing technique were warmly accepted by our readers that is why the HD Tach 2.61 results will certainly be shown. Moreover, we are going to extend further the test suite, and this time you will see several new test programs. The diagrams contain results of other drives with a density of 40 GBytes per platter just for comparison.

Access time and CPUutilization – 7200 rpm
(Ziff-Davis WinBench 99, HD Tach 2.61)

The access time of the WD1200JB turned out to be less than that of its smarter brother and it differs from the specified - 4.2+8.9=13.1 ms. It's surprising that the IBM drive doesn't take the first place though the breakthrough from the leading Maxtor D740X is very small. As far as CPU utilization is concerned I must say that that huge load which was shown by the HD Tach program for the Maxtor D740X with the HPT 372 controller became normal when the drivers were updated in the BIOS up to the v2.31.

Exchange speed – 7200 rpm (Ziff-Davis WinBench 99, HD Tach 2.61)

This time the drives have almost reached 50,000 bytes/sec! It seems that the ATA/100 will become obligatory in the near future. Besides, the Western Digital drives cope excellently with a read speed in the end of the disc.

Look at the graphs.

WD1200BB

WD1200JB

IBM 120GXP

The Western Digital models have almost identical graphs, the IBM has a little shorter zones, especially at the beginning.

The WD drives win in the average read speed but yield to the IBM in the average write speed. Surprisingly, the WD1200JB loses to its junior brother - I thought it would be vice versa.

Ziff-Davis WinMarks 99 – 7200 rpm

Now we are going to examine the drives in standard applications. I think that the buffer size of the WD1200JB will be determining as the tests use relatively small files.

That's the case. The JB beats the WD1200BB and even the IBM despite its better access time.

The complete results can be found in the table.

Intel IOMeter – 7200 rpm

When the load is heavy the IBM outscores the others in 3 access models. The Western Digital drives have just average results. To get a clearer picture I carried out tests for 4 more access patterns which realize streaming and random reading and writing. Here are the results.

The advantage of the WD in streaming reading is explained by its greater speed of reading from a platter, but in the random reading it is the IBM which is a champion. But in the heavy load their results are almost identical. The JB falls behind again.

Well, a large buffer helps only in streaming writing.

The complete results can be found in this table.

Tests in real applications

Now let's see how smart the drives are in some certain applications. We chose 4 types of tasks.

1. processing of images which can't be wholly placed into the RAM. We used the Adobe Photoshop 6.0 and a test file containing an image of 20x20 inches in a resolution of 600 pixels per inch in the TIFF format (576 MBytes). We noted the time of opening of the file, rotation of the image by 90 and 5 degrees clockwise and recording of the file. The time was noted with the timing function of the program.
2. MP3 encoding of a composition which can't be placed wholly into the RAM. We used the RazorLame 3.89 program and a WAV file of 566 MBytes. The time was noted with the help of the log of the program.
3. Archiving of a file which can't be wholly placed into the RAM. We used WinZip 8.1 and WinIce 2.11 programs and files from items 1 and 2. The time was noted with a stop-watch.

Using the Norton Ghost program we created two images of the drives with FAT32 and NTFS file systems. The image contained a standard installation of the Windows 2000 Professional SP2 (with ATA/100 support), 4 above programs and test files in the root directory. Before recording of the image the drive was defragmented by the internal defragmentor.

In the test the image was recorded onto a disc connected as master to the primary channel of the IDE controller; we thus created one partition of the maximum size. After rebooting the secondary channel of the IDE controller was disabled in the BIOS. The disc was defragmented, and the tests were carried out in turn. The tests were conducted in turn three times for each RAM size - 128 and 256 MBytes, and the results were averaged.

The results show that time of MP3 encoding and of archiving doesn't depend either on a RAM size or on a drive used.

Below are the Photoshop results.

Frankly speaking, I didn't expect that the IBM could be worse in recording: this drive outscored the WD1200BB in the Ziff-Davis High-End Disk WinMark. But at least, we can see that the larger buffer has a certain advantage.

Suggestion. Because we will hardly get any new drives before the summer I suggest that we extend the test suite for drives. So, please, send us your ideas. I consider this test experimental. Whether it is successful is for you to decide. Besides, we welcome your explanations on the results. I'm not an expert in Photoshop but the results show that algorithms of rotation of an image by fixed and arbitrary angles differ.

Conclusion

Well, the WD1200JB performed excellently in the Ziff-Davis and Photoshop, but it yielded in the IOMeter. The IBM 120GXP has good scores in the Ziff-Davis, excellent results in the IOMeter, and only in the Photoshop it lost. The WD1200BB is trumped by the IBM (except in the linear read speed and Photoshop). I don't know whether it's worth paying for a large buffer on the whole, but at least in the Photoshop, when working with large images, it's beneficial.