We found out a lot of interesting information about the 320 GB hard disk drives available on the market today. In summary, not all 320 GB drives are equal.

VelociRaptor from Western Digital is the fastest hard disk drive around on this capacity range. The main differences between this disk and other disks are the far lower access time and the far higher minimum transfer rate, meaning that this disk will keep a decent performance while reading its inner-most tracks, thing that doesn’t happen with other units. The problem, however, is its price: it is four times more expensive than a mainstream 320 GB drive.

Some mainstream drives were able to keep a performance very close to VelociRaptor, in particular Seagate Barracuda 7200.11. We were surprised to see this drive being sold by the same price as Barracuda 7200.10, even though it provides a far higher performance. Seagate Barracuda 7200.11 is our recommendation for the average user that is looking for a 320 GB hard disk drive. Other two good options are Western Digital Caviar SE16 and Samsung HD322HJ, even though these two drives achieved a performance a little lower than Seagate Barracuda 7200.11 in some tests.

All other 320 GB hard disk drives should be avoided.

Here is a breakdown of what we found out about each hard drive included in our round-up:

• Hitachi Deskstar P7K500 (HDP725032GLA360): Achieved a performance far lower than the other hard disk drives included in our round-up. It is cheaper than the other reviewed drives and, believe, there is a reason for that. The price difference does not compensate its lower performance. Don’t buy.
• Hitachi Deskstar T7K500 (HDT725032VLA360): The worst hard disk drive from our round-up. Inexplicably it is more expensive than the other model from Hitachi we included in our comparison. Don’t buy. If you have one, replace it.
• Samsung Spinpoint F1 (HD322HJ): A good mainstream hard disk drive, a good option if you can’t find Barracuda 7200.11.
• Seagate Barracuda 7200.10 (ST3320620AS): Barracuda 7200.11 costs the same thing and presents a higher performance. So, don’t buy Barracuda 7200.10. If you can’t find Barracuda 7200.11, buy Samsung HD322HJ or Western Digital Caviar SE16.
• Seagate Barracuda 7200.11 (ST3320613AS): This is the drive we recommend. It provides a burst and average transfer rates comparable to Western Digital VelociRaptor, but costing only ¼ of the price. As mentioned, if you can't find this drive buy Samsung HD322HJ or Western Digital Caviar SE16 instead.
• Western Digital Caviar SE (WD3200AAJS): It is a little bit cheaper than the other drives we are recommending, but frankly spend a little bit more to have a drive with a better performance.
• Western Digital Caviar SE16 (WD3200AAKS): A good mainstream hard disk drive, a good option if you can’t find Barracuda 7200.11.
• Western Digital RE2 (WD3201ABYS): Lousy performance. Don’t buy.
• Western Digital VelociRaptor (WD3000GLFS): Even though it is really the fastest hard disk drive around, we don’t think paying four times more is a good deal for the average user, especially when you can achieve the same burst and average transfer rates with a Seagate Barracuda 7200.11. Of course for the extreme gamer with bottomless pockets building the ultimate gaming machine two VelociRaptors in RAID0 will probably be his best choice, even though you can buy eight Barracuda 7200.11 drives with the same amount of money.