by Aleksey Meyev
01/11/2008 | 03:39 PM
2.5-inch hard disk drives with a recording density of 80GB per platter are quite a widespread variety today. 160GB models (based on two platters) are popular as well, but there are still few models with a capacity of 250 gigabytes. You can only see them in notebooks excepting the Western Digital WD2500BEVS, which is installed into the external drive called Passport (for details see our article called Western Digital Passport Mobile Hard Disk Drive with 250GB Storage Capacity), and the Samsung HM250JI, which is already selling in retail stores. We even had some problems finding 250GB drives for this review. But being highly skilled at eviscerating notebooks and external HDDs, we finally had five HDDs in our hands (one of them is based on three platters, however, as you’ll learn shortly).
By the way, all these drives came out quietly, not accompanied with the marketing noise typical of largest-capacity models. We’ve already got used to a large period of time passing between the official announcement and the actual release of a product (it was as long as half a year for 1-terabyte 3.5” models some of which are still known by announcements only), but the lack of any announcement is a new thing to us. The first 250GB model we obtained was the HDD from Western Digital. After that we received the 250GB Hitachi and, later, the others. The Seagate drive of that capacity was late for the tests.
All HDDs in this review are based on platters that use second-generation perpendicular recording technology. By the way, there is a funny correlation between the capacity of 3.5” and 2.5” HDDs. The largest 2.5” HDD is almost always the same capacity as single-platter 3.5” HDDs of the latest generation. That’s true today: 2.5” 250GB models appeared along with single-platter 3.5” models of the same capacity.
So, after the comparative test of 160GB hard disk drives (for details see our article called Roundup: Six 2.5-Inch Hard Disk Drives with 160GB Storage Capacity) we are about to test the new leaders of this market sector, which are five 250GB models: two from Fujitsu, and one from Hitachi, Samsung and Western Digital each.
Four out of the five HDDs have a spindle rotation speed of 5400rpm, and the Fujitsu MXH2250BT has a speed of 4200rpm. We’ll be able to see how greatly the spindle rotation speed affects performance. The same Fujitsu differs from the others in belonging to the previous generation of HDDs with perpendicular recording. It has three platters and six heads as opposed to the other models each of which has two platters and four heads. Fujitsu must have wanted to reach the storage capacity of 250 gigabytes when developing the MXH2250BT but couldn’t do that with two platters. The addition of a third platter made the HDD thicker than usual: 12.5 millimeters as opposed to the standard 9.5 millimeters. These 3 millimeters of difference seems to be a trifle, yet it is a serious thing when it comes to devices with high component density such as notebooks. HDD bays in notebooks, compact PC cases and external enclosures are designed for standard-size 2.5” HDDs and a drive with a thickness of 12.5 millimeters may just not fit in.
Otherwise, these HDDs are very similar in their declared specs. All of them are connected with a Serial ATA interface and have 8 megabytes of cache memory.
The two HDDs from Fujitsu have different spindle rotation speeds: 4200rpm for the MHX2250BT and 5400rpm for the MHY2250BH. Consequently, they differ in such parameters as latency (the average sector wait time which equals half the time of a full turn of the platter), power consumption and noise level. The MHX2250BT has a latency of 7.14 milliseconds as opposed to the MHY2250BH’s 5.56 milliseconds. The slower model produces some 15% less noise and consumes 0.3W less at reading and writing. Based on three platters, the 4200rpm model is 3 millimeters thicker than the dual-platter MHY2250BH. Fujitsu doesn’t disclose any additional information about these products.
Hitachi has made a point of declaring a new HDD series each time the recording density approaches the next milestone. Here, the HTS542525K9SA00 is the senior product of the new series that comes under the name of 5K250. Of course, the series boasts everything you could have seen in Hitachi’s earlier mobile HDDs such as iridium-manganese-chromium heads, thermal fly-height control, parking on a ramp for protection during reboots, and the power-saving features HiVERT and ABLE. The developer is especially proud of the increased protection against shocks (up to 400G for two seconds) and of reduced noise (in comparison with the previous series).
The HM250JI is the senior model in the M80S series we are already familiar with, so we won’t dwell upon its features. It is endowed with everything a modern HDD must have like the parking of the heads on a ramp and an exclusive acoustic management technology. The 160GB model of this series did well in our earlier tests and now we’ll see if the larger-capacity HDD is just as good.
Finally, we’ve got the recently released addition to the Scorpio series, the WD2500BEVS model. This HDD features a number of exclusive technologies: WhisperDrive technology uses SoftSeek algorithms to minimize noise when seeking; ShockGuard protects the drive’s mechanics and platters from damage; DuraStep Ramp parks the heads off the data zone for additional protection.
The black squares you can see in the photographs of this HDD are used for fastening it in its housing (it was extracted from Western Digital’s external HDD called Passport).
The following testing utilities were used:
We installed the generic OS drivers for the drives and formatted them in FAT32 and NTFS as one partition with the default cluster size. For some tests 32GB partitions were created and formatted in FAT32 and NTFS with the default cluster size. The HDDs were attached to a Promise SATA150 TX2 Plus controller that supported NCQ and were switched from the quiet (with the Advanced Acoustic Management enabled) into ordinary operation mode.
The HDD is receiving a stream of read and write requests with a request queue depth of 4. The size of the requested data block is changed each minute, so that you could see how the drive’s sequential read/write speed depends on the size of the data block.
That’s a good illustration of the influence of the spindle rotation speed on performance: the MXH2250BT is about 15MB/s slower than the others in terms of maximum read speed. The 5400rpm HDDs have similar results, achieving their top speed of 55MB/s on 16KB and larger data blocks. The Fujitsu MHY2250BH has a somewhat lower top speed, yet it is far faster than the MXH2250BT, too.
Note the superb performance of the WD2500EVS on small data blocks: it is 3-5MB/s ahead of its closest pursuer Hitachi on all blocks smaller than 16KB.
The HDDs are different at writing. Of course, the Fujitsu MXH2250BT has a low speed as might have been predicted, but the Samsung HM250JI has a surprisingly low top speed at writing, being 10MB/s slower than the leaders.
The top speed is achieved on different data blocks, too. The HDDs from Samsung and Western Digital reach it as soon as 8KB blocks while the HTS542525K9SA00 and MHX2250BT do it on 16KB blocks. The MHY2250BH accelerates to its top speed on 32KB blocks only.
The HDD from Western Digital is unrivalled when writing small data chunks. Its performance is about two times that of the Samsung and Hitachi. The HDDs from Fujitsu are only half as fast as the latter two.
In this test IOMeter is sending a stream of requests to read and write 512-byte data blocks with a request queue of 1 for 10 minutes. The total number of requests processed by the HDD is over 60 thousand, so we get a sustained response time that doesn’t depend on the HDD’s buffer size. The results are sorted by read response time.
It’s easy to identify the 4200rpm model even if you erase the labels from the diagram: the MHX2250BT is about 15% slower than the others in terms of both read and write response. The high write response of the Samsung should be noted among the others. Samsung’s 160GB model had a rather poor result in this synthetic test, too, but later it delivered superb performance in real-life tests. Perhaps the new Samsung is going to behave like the previous model?
In the Database pattern the HDD is processing a stream of requests to read and write 8KB random-address data blocks. The ratio of read to write requests is changing from 0% to 100% throughout the test.
The following diagrams show the dependence of speed on the ratio of reads to writes.
There is no fundamental difference between the firmware of the two models. The number of operations per second is determined by the spindle rotation speed at every ratio of reads to writes. Overall, the HDDs show the typical behavior of modern 2.5” drives with a slump in the middle of the diagram: reads and writes in equal proportion is the most difficult case for firmware which cannot decide if the buffer segments should be allotted for deferred writing or for look-ahead reading.
The Hitachi shows good scalability of performance depending on load. Its deferred writing strategy is very effective as is indicated by the rise of the graphs in the right part of the diagram. Take note that there is almost no slump in the middle of the diagram as opposed to the graphs of the Fujitsu HDDs.
Samsung acts up again, drawing flat graphs with odd zigzags on the right. This firmware may be defective or, like with the 160GB model, this is the result of incompatibility of the firmware with this particular test. The drive’s real-life performance may be better.
The WD2500BEVS is almost perfect in this test. There are no slumps in the graphs. The drive’s performance increases in proportion to the share of writes at every request queue depth. That’s an example of a good implementation of deferred writing.
This group of tests simulates disk loads typical of servers. Of course, users are likely to prefer other HDDs in their servers, for example SAS models with a spindle rotation speed of 10,000 or 15,000rpm, but we are just interested to see how these 2.5” HDDs perform under such loads. After all, we’ve got the fastest of 4200rpm and 5400rpm HDDs. The results are presented as performance ratings which are calculated by the following formulas:
Rating (File-Server) = Total I/O (queue=1)/1 + Total I/O (queue=4)/2 + Total I/O (queue=16)/4 + Total I/O (queue=64)/6 + Total I/O (queue=256)/8
Rating (Web-Server) = Total I/O (queue=1)/1 + Total I/O (queue=4)/1 + Total I/O (queue=16)/2 + Total I/O (queue=64)/4 + Total I/O (queue=256)/6
As you could expect, the HDD from Western Digital, which has had excellent results in the Database pattern, is in the lead here, too. It is followed by the Hitachi and Samsung. The HDDs from Fujitsu take last places in this test.
Reading numerous small files simultaneously is what the HDD mostly has to do in the Web-Server pattern. The Hitachi finds this load easy but the WD2500BEVS is almost as fast as the leader. The 5400rpm Fujitsu nearly overtakes the Samsung. The 4200rpm MHX2250BT has the lowest performance rating as you could expect.
The Workstation pattern simulates a typical workstation load at request queue depths up to 32. This test is performed on the full capacity of the HDDs as well as on a 32GB partition created on them.
To calculate the overall performance rating of a HDD in this test, we use the following formula:
Rating (Workstation) = Total I/O (queue=1)/1 + Total I/O (queue=2)/2 + Total I/O (queue=4)/4 + Total I/O (queue=8)/8 + Total I/O (queue=16)/16 + Total I/O (queue=32)/32.
The HDD from Western Digital wins the full-capacity test but the HM250JI is close behind. The other 5400rpm drives are slower and equal to each other.
It’s different when the test zone is limited to a 32GB partition: the two groups change places, the Hitachi becoming the leader and the Samsung sinking to fourth place. The MHX2250BT is the slowest of all again.
The multi-threaded tests simulate a situation when there are one to four clients accessing the hard disk at the same time. The depth of the outgoing request queue is varied from 1 to 8. We’ll discuss diagrams for a request queue of 1 as the most illustrative ones.
This test has been a hard nut to crack for many HDDs. It is the Samsung HM250JI that fails now. This HDD keeps all right with one data thread but slows down dramatically when there are more threads to be processed. As a result, it is slower at processing multiple threads even than the MHX2250BT although the latter has a spindle rotation speed of 4200rpm.
The HDD from Western Digital is a leader again. The Hitachi has good results, too.
Western Digital’s drive is the only one to remain a confident leader while the others change places in the diagram. Being good at reading multiple threads, the HTS542525K9SA00 is the slowest of the 5400rpm drives at writing and even slower than the MHX2250BT at processing four threads. The HM250JI, on the contrary, copes well with writing multiple threads. Its performance with one thread is rather depressing, however, but it is easily explained if you recall this drive’s result in the sequential writing test.
First, you can have a look at the data-transfer diagrams of the drives:
Western Digital WD2500BEVS
There’s nothing particular exciting about the diagrams. The only notable thing is the data-transfer graph of the Samsung drive: the characteristic jaggies are indicative of two platters with different read speeds.
The data-transfer speeds at the beginning and end of the logical disk are listed in the following diagram, sorted by the speed at the beginning.
First place goes to the Samsung. The HDD from Western Digital is second, the drives from Fujitsu take last places.
The next diagram shows the results of WinBench 99 tests on a 32GB partition sorted by the High-End Disk Winmark results.
The detailed WinBench 99 results are available in the tables below (click to enlarge):
The WD2500BEVS is ahead irrespective of the file system and enjoys a big lead over the second-best HM250JI. The HTS542525K9SA00 is fourth here. We mention the drive that takes fourth place because fifth place usually goes to the MHX2250BT which is hamstringed by its lower spindle rotation speed.
Now we will check performance of the hard disk drives with the FC-Test program. Two 32GB partitions are created on the drives and formatted in NTFS and then in FAT32. After that a file-set is created of the hard disk. It is then read from the disk, copied within the same partition and then copied into another partition. The time taken to perform these operations is measured and the speed of the drive is calculated.
To remind you, the Windows and Programs file-sets consist of a large number of small files whereas the other three patterns (ISO, MP3, and Install) include a few large files each.
We’ll discuss the FAT32 results first.
It’s all just as you could have expected: the HDD from Western Digital is ahead with every file-set, especially with large file-sets. Second place goes to the Samsung which seems to make excuses for its poor performance in the IOMeter tests. The Hitachi is the worst of the 5400rpm models, being only better than the Fujitsu MHY2250BH with the ISO file-set. The 4200rpm model is far slower than the others.
Every HDD, excepting the MHX2250BT, copes with this test equally well. The HDD from Western Digital isn’t too far ahead while the MHY2250BH is not too far behind the others.
The HDDs differ more in the copying tasks. The drives from Hitachi and Western Digital are in the lead with large files, and the WD2500BEVS is somewhat slower than the leader. The Samsung is ahead with small files when the HDD from Western Digital sinks to third place, outperforming the two Fujitsu HDDs. The Hitachi seems to be the overall winner of the copying tests.
Now let’s see what we have in the same tests but when the HDDs are formatted in NTFS.
The WD2500DEVS is unrivalled at writing. The HDDs line up just as they did in the FAT32 test, except that the MHY2250BH outperforms not only the HTS542525K9SA00 but also the HM250JI in the Windows pattern.
There are some minor changes in the results of the reading test. The HDD from Western Digital is habitually in the lead, followed by the Samsung. The Fujitsu drives obviously feel better working with NTFS. Of course, this cannot help the MHX2250BT leave the last place but the MHY2250BH is much more confident now.
The Hitachi is still the best drive when it comes to copying within the same partition. The Samsung has become somewhat slower with small files but faster with large ones than in FAT32. The HDD from Western Digital wins at copying from one partition to another again. The HDDs from Fujitsu have low speeds when copying files.
PCMark04 benchmarks the HDD in four different modes: Windows XP Startup is the typical disk subsystem load at system startup; Application Loading is the disk activity at sequential starting-up and closing of six popular applications; File Copying measures the HDD performance when copying a set of files; the Hard Disk Drive Usage parameter reflects the disk activity in a number of popular applications. These four parameters are used to calculate the overall performance rating according to the following formula:
HDD Score= (XP Startup Trace x 120) + (Application Load Trace x 180) + (File Copy Trace x 28) + (General Usage x 265)
The HDD from Western Digital steps up on the top of the podium, the Hitachi occupying the second step of it. The drives from Fujitsu take last places again.
The Hitachi is the fastest at loading applications. On the other hand, it is a mere 0.04MB/s ahead of the Western Digital, so the two are roughly similar.
You can see the difference between the HDDs due to the spindle rotation speed again. Performance and power consumption are hardly compatible – you have to choose one at the expense of the other.
The Samsung wins this copying test. It did have very good copying results in the File-Copy Test, yet they hardly agree with the 1.5MB/s lead over the Hitachi we can see here. PCMark produces really odd results sometimes.
The Samsung is the best drive for General Usage. The Western Digital, which has won many of the previous tests, is only third here.
The HM250JI has the highest overall score, followed closely by the HTS542525K9SA00. The WD25000BEVS takes third place. The leading trio have similar scores as opposed to the two sluggish drives from Fujitsu.
New in our HDD tests, this section offers the results of power consumption tests according to our own methodology. You can read about it in our article called Hard Disk Drive Power Consumption Measurements: X-bit’s Methodology Indepth. We can also add a few words about the specific operation modes in which we perform the measurements.
First of all, it is the start-up moment when the platters spin up and the heads get unparked. Second, we measure the consumption in idle mode when the drive is not being accessed but its platters are rotating and the heads are ready to work. And finally, there are two work modes: random-address reading/writing and sequential reading/writing. These are emulated by means of the appropriate IOMeter patterns.
Note that 2.5” HDDs, contrary to their 3.5” counterparts, are powered by the +5V line only and do not take any power from the +12V line. The currents below can be easily transformed into power by calculating their values by 5.0V.
Unfortunately, we couldn’t measure the power draw of the MHX2250BT, but we are going to compare power consumption of HDDs with different spindle rotation speeds in our upcoming reviews.
Now, let’s see how much power the four 250GB 5400rpm drives need. For each mode, except Start, the average value, accumulated for 60 seconds of measurement, is provided.
The following diagrams show the amount of power consumed.
The Hitachi proves to be the most economical drive at startup, its consumption current being only 0.72A. The Samsung needs 0.03A more. The HDDs from Western Digital and Fujitsu consume 0.78A each. Note that these values are higher than 0.5A which can be provided by the USB. No wonder that such HDDs cannot start up without additional power if placed into an external enclosure and connected to a USB port of a regular mainboard or notebook.
There are two pairs of HDDs in Idle mode: the Hitachi and Fujitsu have a consumption of 0.8W. The Samsung and Western Digital need 0.9W.
When processing random-address requests, the HTS542525K9SA00 is the most economical drive while the MHY2250BH and WD2500BEVS are the most voracious in read and write mode, respectively.
Every HDD, except for the one from Western Digital, has a higher average consumption current at reading than at writing. We guess it is due to the HDDs’ ability to accumulate and reorder write requests to optimize the route of the heads.
The Hitachi is the most economical at sequential operations as well. The HDD from Western Digital has the highest consumption of all, 2.9W both at reading and writing. Note again that this is more than the USB connector can deliver when it comes to using these HDDs as external ones. The excellent performance in most of the tests has the tradeoff of high power consumption. By the way, we’re talking about average values but there occur occasional spikes of supply current that are sometimes even higher than the values measured at the startup moment.
The HDDs have roughly the same power draw at random-address and sequential requests, except for the WD2500BEVS that requires much more power in the latter case although the heads are moving more actively at random requests. We guess the explanation goes like this: the heads unit of a modern 2.5” HDD is very light and requires little power to move. Some more power is spent to keep the platters rotating, but the main consumer is the processor that keeps the head above the track, works with the buffer and calculates the read and write strategies. That is, the certain reduction of power consumption from the shorter movements of the heads in sequential-request mode is negated by the increased consumption of the electronics due to the increased amounts of transferred data and the necessity to maintain the position of the head above the given track.
The Western Digital WD2500BEVS seems to be the overall leader among 2.5” HDDs with a storage capacity of 250GB. It never failed in any test but won many of them, delivering high sequential read and write speeds and showing good firmware algorithms. On the downside is the high power consumption of this model. It is actually the most voracious model in its class and we don’t recommend using it in an external enclosure without additional power (or you should switch the HDD into quiet seek mode).
The Samsung HM250JI and Hitachi HTS542525K9SA00 are worthy of your attention, too. The former proved to be suitable for a workstation or notebook. The latter has high performance with small files, copes well with copying tasks, and has the lowest power draw among the tested HDDs.
Fujitsu has got some work to do on the firmware of the MHY2250BH, which has been the slowest in the 5400rpm category in many tests.
The Fujitsu MHX2250BT with its spindle rotation speed of 4200rpm could not be expected to set any records. Its results are 15% lower than those of the worst of the 5400rpm drives throughout most of the tests. So, if you need a high-performance disk subsystem, you should not buy a low-speed model.