I've had my first notebook hard drive death (well, actually, it's currently dying... clicking noises, super slow windows boot up ...)

Anyway, I now I realize I don't know anything about laptop hard drives. I was just going to take one out of another laptop and stick it in but the connectors are the same.

How do you shop for laptop hard drives?

4 Answers 4


Interface (connectors):

laptop PATA vs SATA http://www.laptopparts101.com/wp-content/uploads/2008/12/sata-ide-laptop-hard-drive.jpg

  • Parallel ATA a.k.a. IDE, ATA, ATAPI, UDMA and PATA — legacy, wide 40-pin connector for disks produced few years ago. In case of notebook drives pins are smaller, and there is also power supply in the same plug.

  • Serial ATA (SATA) — modern connector. Most modern laptops use it. 6 data pins and 15 pins including power supply.

Sizes of laptop disks:

1.8" and 2.5"

  • 2.5" — most common
  • 1.8" — reduced, used mostly in ultralights and netbooks.

Rotation speed:

  • 7200RPM — modern, high-end 2.5" disks. Consume more energy.
  • 5400RPM — standard, low-end 2.5"disks or high-end 1.8"disks. More energy-efficient.
  • 4200RPM — legacy, low-end 2.5" disks, some modern reduced height and energy-efficient 2,5" or standard 1.8"disks.

Take in account, that 5400RPM HDD with bigger capacity actually might have faster transfer rates, than smaller capacity 7200RPM. Rotation speed does however directly affect seek times.

HDD vs. SSD:

Modern alternative to mechanical HDDs are Solid State Drives, based on flash memory. They have almost instantaneous seek times, incredible read speeds and very low power consumption. As of now they are still much lower capacity than similarly priced HDDs. However, with the effects of Thailand floods and sharp drop in SSD prices in recent years, there are no longer excessively expensive. SSD can come in 2.5" SATA form factor, thus be interchangeable with 2.5" HDD. Another form factor, unique to SSDs is Mini-SATA (mSATA), intended mostly for use with netbooks (and some ultraportables). Below mSATA drive on top of 2.5" SATA HDD for size comparison:

mSATA compared with 2.5" SATA HDD

Note, that ultrabooks use neither of these formats. In ultrabooks SSDs are soldered permanently onto motherboard, thus cannot be removed nor upgraded.

  • +1 for the connector image from laptopparts101.com.
    – Bratch
    Mar 21, 2010 at 19:30
  • Just curious, but what do you mean when you say "high-end" vs "low-end"? Oct 9, 2011 at 20:38
  • @Dark: I mean prosumer/enthusiast market vs. consumer market.
    – vartec
    Oct 10, 2011 at 10:08

You asked how to shop for notebook hard drives. I prefer to hit my favorite review sites and look in their storage review sections. One of these always seems to have a good comparison review between hard drive vendors:

The one thing to be aware of is that there's some high-capacity drives that are taller than other drives. Your laptop may only tolerate a 9.5mm high drive, for example - so don't go buying a 12mm high drive unless you know it'll fit.


There are, really, only two types of drive connections: Regular old IDE (PATA) and SATA. Each use their own connector, and more importantly data transport protocol. So you have to buy the correct interface for your laptop. That being said most laptops will have another, specialized, connector that actually hooks the drive into the controller. As a result it can, on first blush, be non-obvious whether you are working with a SATA or PATA drive. That connector, however, should come off the old drive easily. Once you've figured out whether you need IDE or SATA look for 4 things. Size, Speed (rotational and seek time), Cache, and Warranty. First, figure out the size that you want, then try to maximize the rest based on the price you're willing to spend.

  • so SATA,PATA, Ultra ATA... all the same connector?
    – carrier
    May 25, 2009 at 16:31
  • P-ATA is just another (new) name for IDE. P stands for parallel to distinguish ist from S-ATA (serial)
    – splattne
    May 25, 2009 at 16:41
  • Ultra ATA is a transfer mode that was used on PATA drives, except they were called IDE back then. May 26, 2009 at 8:56

After installing a new ATA hard drive, don't use more space than is recognized by the BIOS. Otherwise there will be an addressing overflow and data will be written at the beginning of the drive and trash the boot sector. (Learned the hard way).

  • Wrap around? Around what?
    – Bill Weiss
    Jun 23, 2009 at 23:32
  • Clarified answer.
    – Mike
    Jun 24, 2009 at 13:50

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