Seagate Momentus 750GB 7200rpm Hard Drive Review

Seagate Momentus 750GB 7200rpm Hard Drive Review

by Philip Bloem

Today we are going to have a look at the industry’s first 750GB 7200rpm notebook hard drive: the Seagate Momentus ST9750420AS. This model has two 375GB platters inside a normal 2.5 9.5mm high case. That’s a total of 750GB spinning at 7200 revolutions per minute. Could this be the ultimate notebook hard drive? Read on to find out.

Seagate Momentus ST9750420AS Specifications

  • Model Number ST9750420AS
  • Interface SATA 3Gb/s
  • Cache 16MB
  • Capacity 750GB
  • Areal density (avg) 541Gb/in2
  • Height 9.5mm (0.370 in) Width 69.85mm (2.750 in) Length 100.35mm (3.951 in)
  • Weight (typical) 115g (0.254 lb)
  • Spin Speed (RPM) 7200RPM
  • Average latency 4.2ms Random read seek time 11.0ms
  • Random write seek time 13.0ms
  • I/O data transfer rate 300MB/s

Build and Design

The Seagate ST9750420AS looks like any other Seagate Momentus hard drive. We’re talking about a standard 2.5-inch notebook hard drive. Here’s the 7200.5 next to the Momentus XT.

Synthetic Performance

To get an impression of the synthetic performance we ran the HD Tune benchmark.

The ST9750420AS read performance looks very good. The first 225GB reads above 100 MB per second on average. The average read speed on the whole drive is 87 MB per second. The access time also looks very good with 15.3 milliseconds on average. So synthetic performance looks very good, does this mean it will perform equally well in real life? That’s what we’re going to look at now.

Real world performance

To find out how ST9750420AS performs in real life I build it into the Acer 1830T test system and performed a series of tests.

Test system:

  • Acer 1830T 11.6 notebook
  • Core i3 330um CPU
  • 4GB memory
  • Software: Windows 7 x64, Intel RST driver, Adobe Photoshop CS 4, MS Office

For comparison I used the following hard drives:

  • Seagate Momentus XT 500GB, a very fast hybrid drive.
  • Western Digital Scorpio Black 500GB WD5000BEKT, a fast 7200rpm hard drive.
  • Toshiba MK2565GSX 250GB, a relatively fast 5400rpm with a single 250GB platter.
  • Western Digital Scorpio Blue 640GB WD6400BEVT, a relatively slow 5400rpm drive.

First I installed a default image to the hard drive and after that I installed Microsoft’s Office suite. The chart shows the time it took to install Office .

The ST9750420AS isn’t very fast with installing programs. While it is faster than the 5400rpm Western Digital, it loses against the well performing 5400rpm Toshiba hard drive.

Booting Windows 7

Next, I measured how fast these drives boot Windows 7 with the utility Boot Timer. The Seagate 750GB boot performance isn’t particularly impressive. It’s about equal to the 5400rpm drives.

To get an accurate indication of the file copy performance, I then copied and pasted a 7GB folder on to the same partition. The folder contained images, video files and program files.

File copy performance is ok. While it’s not as fast as the two other 7200rpm drives, the Seagate 750GB manages to outperform the two 5400rpm drives.

Launching Applications

Next we opened up Photoshop CS4 64 bit, Microsoft’s Word and a large document containing text and images. The time shown in the table is for all actions combined together.

Here we see a better performance by the Seagate. It still lags behind the two fastest hard drives but manages to outperform the 5400rpm drives by a comfortable margin.

Next I started a virus scan with Avast. While the scan was still running, I opened a document in Word. The time shown in the chart is the time it took to open the document and Word.

The Seagate 750GB does well here, it’s as fast as the WD Scorpio Black. The Momentus XT benefits from its 4GB cache and is the fastest.

Multi task performance

Performing multiple tasks at once is becoming more and more common these days. When for example a virus scanner or Windows update is running in the background, one wants to be able to use their notebook without sacrificing performance. Our multi-task test consisted of scanning a large folder of files with Avast Virus scanner, while at the same time copying a folder and decompressing a zip file with 7zip. The time shown in the table is the time it took to finish all tasks.

Again we see the Seagate 750GB trail the fastest hard drives and outperforming the 5400rpm drives.

Battery life

To get an indication of battery life I used Battery Bar 3.4.3. The battery was charged to 80%. With 40% brightness and Windows set to Balanced profile, a video was played in Windows Media Player. After that the battery life indication was read from Battery Bar.

The Seagate 750GB didn’t do very well in this short battery life test. It delivered about half an hour battery life less than our 5400rpm drives. While this battery life test isn’t totally accurate, I think it’s safe to assume that people looking for a drive with very low power consumption are better off with a low power 5400rpm drive.

The battery life was measured on a 11.6 notebook with Ultra Low Voltage CPU. People with a larger notebook with a full voltage mobile CPU will typically see smaller differences between hard drives.

Noise and Vibration

The Acer 1830T test notebook is very light and small notebook. It tends to let through noise and vibration coming from the hard drive. The Seagate 750GB did well in this area. It was barely audible and the vibrations were minor. Other 7200rpm hard drives like the Scorpio Black and Momentus XT were slightly noisier and caused slightly more vibration.


While the Seagate Momentus 750GB 7200rpm was a decent performer overall, I had hoped it was faster. Its performance was generally faster than 5400rpm drives in most situations, but it’s not as fast as the fastest 7200rpm drives. People looking for a large and reasonably fast hard drive should consider the Seagate Momentus 750GB. People looking for the fastest hard disk drive are better off with the hybrid Momentus XT or WD Scorpio Black.


  • Large 750GB capacity
  • Reasonable overall performance
  • Relatively quiet when compared with other 7200rpm drives


  • Not as fast as the fastest 7200rpm hard drives
  • Slow installation performance
  • Uses more power than 5400rpm drives





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