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Original Link: https://www.anandtech.com/show/591
IBM Deskstar 75GXP Ultra ATA 100 Hard Drive
by Scott Gooden on July 26, 2000 12:00 PM EST- Posted in
- Storage
Introduction
IBM has long been known as a leader and an innovator in new technologies that help boost the performance and capacity of modern storage devices. While IBM offers many solutions for different data storage needs, most of our readers are familiar with their Deskstar and Ultrastar hard disk drives, for the desktop and server markets. IBM makes no exception in the Deskstar family, when it comes to their philosophy of providing innovation and quality in their products, as evidenced by the introduction of the Deskstar 75 GXP and the 40 GV disk drive lines. While these two model lines incorporate similar features, which I will go over shortly, the 75 GXP line is aimed at the performance user, while the 40 GV line is aimed more at the cost conscience user.
Both of these drives offer some of the highest data densities available today, with the 40 GV having densities of 20 GB per platter, it is able to provide 40 GB’s of storage with just two platters. The 75 GXP has densities of 15.3 GB per platter, and is able to achieve 75 GB’s of storage using 5 platters. While at first glance it may seem that the 40 GV would offer superior performance due to its higher platter densities, those higher densities are offset by it’s lower spindle speed.
The 40 GV drives operate at 5400 RPM and has a 512 KB cache, while the 75 GXP drives offer 7200 RPM spindle speeds, along with a larger 2 MB cache, allowing for better overall performance. The reason the 40 GV drives are able to offer higher platter densities is that as spindle speeds are increased, it becomes harder to reliably read tightly packed data off of the platters. So while the 75 GXP is limited to lower data densities due to its 7200-RM spindle speed, the net effect is that it still offers superior performance because of the increased speed. These factors combine to allow the 75 GXP to provide sustained data transfers of 37 MB/s, versus the 32 MB/s, the 40 GV is able to achieve. The 75 GXP also has an improved average seek time of only 8.5 ms, compared to the 9.5 ms of the 40 GV, allowing for slightly faster access time.
The Drive
The IBM Deskstar 75GXP series incorporates several new technologies that help to enhance drive performance. By utilizing glass media (data platter’s), a differential preamplifier, and fifth-generation GMR (Giant Magnetoresistive Heads) heads, IBM was able to increase track capacities an average of 41 percent. Due to the increased data densities and fast spindle rates of the 75 GXP, IBM has incorporated a thermal monitor into the drives, to help ensure data reliability.
The 75 GXP is also the first desktop drive that includes IBM’s safety ramp feature. The safety ramp feature safely parks the data heads off the media surface when powering down which helps to protect data during spin up/ spin down cycles. In order to help keep drive noise down, a laminated top cover and ceramic spindle bearings are used, together they can reduce drive acoustics by up to 7 dB.
By utilizing the above technologies, the IBM Deskstar 75GXP series of drives are able to achieve data densities of 15.3 GB’s per platter. The high densities allow the top end drive in the 75 GXP model line to top out at 75 GB’s of storage capacity, by utilizing 5 platters, hence the 75 GXP model name. Along with the 15.3 GB/platter data densities, the 75 GXP drives have spindle speeds of 7200-RPM, allowing the drive to obtain sustained transfer rates of 37 MB/s, according to IBM.
In addition to the 15.3 GB per platter densities, and 7200-RPM spindle speed, the 75 GXP has an average seek time of 8.5 ms and a 2 MB of cache memory. Combining the 8.5 ms average seek time with the 4.17 ms latency, typical of a 7200 RPM drive, the 75 GXP has an overall access time of 12.7 ms. The 2 MB of on-board cache allows data being read from the disk to be more adequately buffered during sequential transfers, as well as allowing more data to be stored from read ahead operations, thus taking better advantage of the 75 GXP’s high speed interface.
The IBM 75 GXP is also one of the first drives on the market to use the new Ultra ATA/100 interface. This interface allows data transfers between the disk drive and IDE controller on the motherboard, of up to 100 MB/s. While the actual sustained throughput of any single drive falls far short of this specification, the benefits of having such high bandwidth shows up when transferring bursts from the hard drives cache memory. It is also helpful when using multiple disks on the same IDE channel, such as when using a striped RAID array.
In order to operate the IBM 75 GXP disk drive under the Ultra ATA/100 interface; you must have an Ultra ATA/100 controller card installed, or utilize a motherboard which has an Ultra ATA/100 compatible chipset and BIOS. In addition, you will need to use a 40-pin, 80-conductor IDE cable, in order to connect your drive to the motherboard or controller card. These are the same cables as currently used for the Ultra ATA/66 drives, so you can use one of these if your drive did not come with one. If your system does not meet the above requirements, the drive will not run at Ultra ATA/100 speeds. However, it is full backward compatible, so if you fall into the above situation, your drive will fall back to either Ultra ATA/66, or Ultra ATA/33 speeds, depending upon your system configuration.
One additional thing we will mention quickly is; if you are new to using disk drives which use either the Ultra ATA/66 or UltraATA/100 interfaces, the 40-pin, 80-conductor cables that these drives require have color coded connectors. You would connect the cable as follows: the blue connector is attached to the motherboard or controller card, the black connector is for the drive you have set as Master, and the gray connector is for the drive you have set as Slave.
Specifications
The IBM 75 GXP line contains six drive models, which offer users a broad range of capacities, and price points, to choose from. Because the 75 GXP series has 15 GB platter densities, or 7.5 GB per data surface, the capacities of the various models are derived from the number of useable data surfaces that each drive has. Remembering that there are two data surfaces per platter, you can easily determine the number of platters that each model contains. Like many other manufactures, IBM offers two different drive models that incorporate two disk platters. As you can determine by reviewing the chart below, the 20 GB drive uses only three of the available 4 data surfaces, while the 30 GB drive uses all 4 data surfaces. This is why it is preferable to think in terms of usable data surfaces rather than just the number of platters.
In the following chart we have listed the entire IBM 75 GXP model line:
Model
Number
|
Formatted Capacity |
Data
Surfaces / Heads
|
DTLA-307015 |
15 GB’s |
2 |
DTLA-307020 |
20 GB’s |
3 |
DTLA-307030 |
30 GB’s |
4 |
DTLA-307045 |
45 GB’s |
6 |
DTLA-307060 |
60 GB's |
8 |
DTLA-307075 |
75 GB's |
10 |
The IBM Deskstar 75 GXP product line contains drives with capacities of: 75, 60, 45, 30, 20, and 15 GB’s. All of the drives in the 75 GXP line also feature 2 MB of cache memory and 8.5 ms average seek times. The following chart lists specifications common to all of the drives in the IBM 75 GXP line:
IBM 75 GXP |
|
Seek Time (Track to Track) |
1.2
ms
|
Seek Time (Average) |
8.5 ms |
Seek Time (Maximum) |
15 ms |
Average Latency |
4.17 ms |
Rotational Speed |
7200 RPM |
Controller Overhead |
< 0.3 ms |
Start Time (From stop to drive ready) |
15 sec |
Disk Transfer (To and from interface) |
100 MB/sec |
Disk Transfer (To and from media) |
444 Mb/sec |
Buffer Size |
2 MB |
Data Zones per Surface |
15 |
Bytes per Sector/Block |
512 |
Power Requirements/Environment | |
Seek | 12.9 Watts |
Read/Write | 6.8 Watts |
Idle | 6.7 - 8.1 Watts* |
Standby | 1.4 Watts |
Acoustics at Idle | 3.0, 3.1, 3.6** bel |
Operating Temperature | 5 – 55 C |
*8.1 Watts for 60 and 75 GB models, 6.7 for others.
**3.6 bel for 60 and 75 GB models, 3.1 bel for 45 GB model,
3.0 bel for 30, 20, and 15 GB models
The Test
The AnandTech storage test bed is currently set up using Windows 98, Windows NT 4.0 Service Pack 6 and Windows 2000. Each operating system is set up using its own 4 GB partition with Windows 98 using the Fat 32 file system, Win NT 4.0 using the NTFS file system and 2 instances of Windows 2000, one using the FAT 32 file system and the other using NTFS. Since Windows 2000 supports both file systems, we decided to set up two platforms to help compare the performance under both situations. This will help the reader make an informed decision as to which drive performs best under each file system, for users planning to upgrade to Windows 2000. Also, all of the tests were run using the Ultra ATA 66 protocol, using an 80-pin IDE cable. In all instances, the only installed software is the operating system and the benchmark programs. The test drive is being run as the D: Drive in all instances, operating as master on the secondary IDE channel. The operating system and all benchmark programs are contained on the boot disk, or the C: Drive, which operates as the master on the primary channel.
The complete test bed is as follows:
- Intel
Celeron 500 MHz CPU
- Intel
CA810E motherboard with native Ultra ATA/66 support
- 128
MB Corsair PC100 SDRAM
- Ultra
ATA/66 40-pin, 80-conductor HDD cable
- Microsoft
Windows 98
- Microsoft
Windows NT 4.0 SP6
- Microsoft
Windows 2000 (FAT 32)
- Microsoft
Windows 2000 (NTFS)
- Ziff
Davis Winstone 2000 CC
- Ziff
Davis Winstone 99
- Ziff
Davis Winbench 99
- Adaptec Threadmark 2 (Windows 98 and NT4 only)
Each hard disk was partitioned and formatted before each suite of tests on their respective operating systems, as to prevent any skewing of the test results. For purposes of consistency, each benchmark was run a total of 5 times, with the final score being the average of those five runs. The machine was rebooted between each test as to minimize the effects of any carryover from previous tests.
In addition to the above tests, we have added a temperature measurement of the test drive, while it is in operation. This measurement will be made with a standard thermocouple probe taped to the outside of the hard drive’s cover. All measurements will be made with the tested drive mounted in a normal drive bay, in a closed case. This will most closely resemble the normal conditions the drive will run in.
The temperature measurement test will produce 4 readings for each drive. These readings will be: average room temperature during the measured tests; average case temperatures during the measured tests; average drive temperature during measured tests; and finally the peak temperature the drive reached during the testing. All temperature tests will be done during the Windows 2000 NTFS portion of the testing, to ensure consistency. The temperature will be recorded every 30 minutes during the suite of tests and the results averaged. The peak temperature result will come from the peak hold feature of the thermometer.
In the following benchmark results, the IBM 75 GXP results are compared with the data from previously tested hard drives to help give a more accurate picture of where it stands. For more insight into our choice of test bed and testing conditions, you can take a look back at the March 2000 hard drive roundup.
As you can see, the IBM 75 GXP gets off to a slow start under Windows 98 SE, only managing to take second place under Business Winmark 99.
Here the story changes though, as the IBM 75 GXP runs away with the show, with a 1.1 MB/s lead over the nearest competitor.
In the Disk Transfer Tests, the IBM 75 GXP kicks into high gear, as its 15.3 GB per platter data densities allow it to lead the pack by 6.2 MB/s in the outer tracks. Its lead slips somewhat near the inner tracks, as it falls .6 MB/s under the Quantum Fireball Plus LM's score, but its overall average is still way above the nearest competitor.
The 4.2% in the above charts shows the CPU utilization of the IBM 75 GXP during the disk inspection portion of the ZD benchmarks. The benchmark display engine is not currently set up to display these scores properly, however, they will be available when we implement the new benchmark engine.
Under Business Winstone 99 the IBM 75 GXP falls back in line with the rest of the pack, turning in a solid 2nd place showing behind the Maxtor and Quantum drives.
Under Content Creation 2000 the 75 GXP once again shines, as it manages to distance itself .7 Winstone points ahead of the tightly grouped competition.
Although the Adaptec Threadmark 2.0 is getting quite old, it is still an useful measure of performance when comparing similar drives on the same platform. Here we can see that the IBM 75 GXP manages to beat out the highly rated Maxtor DiamondMax Plus by .3 MB/s. It also comes in slightly lower on CPU utilization that the Maxtor.
I would like to comment that this is one area where the Adaptec Threadmark benchmark is beginning to show its age, as the CPU utilization numbers here are a bit misleading. While the Threadmark numbers are quite high, the IBM 75 GXP uses only about 4.0% CPU utilization during the ZD benchmarks. While we currently do not list the ZD Benchmark CPU utilization scores, they will be available for viewing on all of the drives we have tested, once the new benchmark engine gets put into place.
We think the results here speak for themselves.
We also want to bring up the fact, that in order to cut down on the number of benchmark pages you need to scroll through, we have included only the Windows 98SE and Windows 2000 NTFS benchmark scores. We have omitted the Windows 2000 FAT 32 scores in this review, as they are similar to Windows 98 performance, and felt most Windows 2000 users would be most interested in the NTFS results. Once the new benchmark engine is in place, you will be able to view the results under all of the different configurations in which we tested.
Once again the IBM 75 GXP dominates the field, as it pulls away with a .8 MB/s lead over the nearest competitor.
Under Windows 2000 the Disk Transfer Test results are the same as under Windows 98 SE, with the IBM 75 GXP on top.
No surprises here.
Temperature Tests
The IBM 75 GXP is one of the coolest drives we have tested under our new temperature testing methodology. While this is only the third drive we have tested that has included temperature data, we think the low figures here represent the kind of quality that IBM engineered into this drive. Although we currently only have temperature data a few drives, the results obtained so far seem to be within the reasonable limits that one would expect a hard drive to operate within, and well within the manufacturers safe operating limits. We do intend to include this test in all of our upcoming reviews, so eventually we will have more data to help make meaningful comparisons. Once we have data from a few more drives, we will present the information in a graphical form. Until then, we will just present each drives results within its respective review. |
Final Words
The IBM 75 GXP is undoubtedly one of the fastest IDE drives we have tested to date. With a strong showing in almost all of the benchmarks, the 75 GXP easily takes the crown away from the Maxtor DiamodMax Plus 40.
Although the IBM 75 GXP is the new leader in IDE hard drive performance, we are awarding it a 8.0 overall score on our rating system. While this is the same score we awarded to the Maxtor DiamondMax, you have to take into consideration the timeframe of the reviews. So even though the scores are the same, the IBM GXP 75 represents a 8.0 in current drive technology, whereas a drive that scored a 8.0 a year ago would hardly be equal in performance to any of the drives currently on the market.
The IBM 75 GXP is also one of the quietest drives we have tested. Anyone looking for a near silent drive will appreciate the noise reduction technologies IBM has incorporated into the 75 GXP. While at the present moment, the noise level evaluation is a subjective opinion, we do plan to come up with a way to isolate the drive being tested and measure its noise level in a controlled manner.
With features such as an Ultra ATA/100 interface, 7200-RPM spindle speeds, 2 MB of cache, and 15.3 GB per platter data densities, the IBM 75 GXP delivers excellent performance. Add to this, storage capacities of up to 75 GB’s, along with drive silencing technologies, and we are sure you will be making a wise decision should you choose to include this drive in your system.
Reviewed Drive: IBM 75 GXP (DTLA-307015) 15 GB Hard Drive
Main Features: 7200-RPM, Ultra ATA/100 interface, 2 MB cache, 15.3 GB per platter data densities, 8.5 ms average seek times and capacities of 15, 20, 30, 45, 60 and 75 GB’s.
Warranty: 3-years
Estimated Price: $150.00 (15GB model)
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How it Rates
AnandTech Hard Drive Rating |
|
Rating
(x/10)
|
|
Performance
|
8.0
|
Features
|
8.0
|
Price
|
6.5
|
Availability
|
6.5
|
Documentation & Software Bundle
|
6.0
|
Overall Rating - Not an Average - Click here to find out why |
8.0
|