Understanding Hard Drive Performance

Application Performance: Windows XP Start

Application Performance: File Writing

Welcome The Barracudas: 250, 320, 400, 500, 750 GB

We already talked about manufacturers cropping storage capacity for the sake of providing products for common "sweet spot" capacity points. Now let's check what the difference is between the slowest and the fastest Barracuda 7200.10 drives. As we'll see, the rule of thumb of the top model being the fastest clearly isn't valid here.

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ManufacturerSeagateSeagateSeagateSeagateSeagate
SeriesBarracuda 7200.10Barracuda 7200.10Barracuda 7200.10Barracuda 7200.10Barracuda 7200.10
ModelST3250820AST3250820ASST3320820AST3320820ASST3400620AS
Capacity250 GB250 GB320 GB320 GB400 GB
Rotation Speed7200 U/Min7200 U/Min7200 U/Min7200 U/Min7200 U/Min
Platter22223
Cache888816
Native Command Queuing (NCQ)noyesnoyesyes
InterfaceUltra ATA/100SATA/300Ultra ATA/100SATA/300SATA/300
Row 8 - Cell 0
ManufacturerSeagateSeagateSeagateSeagateSeagate
SeriesBarracuda 7200.10Barracuda 7200.10Barracuda 7200.10Barracuda 7200.10Barracuda 7200.10
ModelST3400820AST3400820ASST3500630AST3500630ASST3500830A
Capacity400 GB400 GB500 GB500 GB500 GB
Rotation Speed7200 U/Min7200 U/Min7200 U/Min7200 U/Min7200 U/Min
Platter33333
Cache8816168
Native Command Queuing (NCQ)noyesnoyesno
InterfaceUltra ATA/100SATA/300Ultra ATA/100SATA/300Ultra ATA/100
Row 18 - Cell 0
ManufacturerSeagateSeagateSeagateSeagateRow 19 - Cell 5
SeriesBarracuda 7200.10Barracuda 7200.10Barracuda 7200.10Barracuda 7200.10Row 20 - Cell 5
ModelST3500830ASST3750640AST3750840AST3750640ASRow 21 - Cell 5
Capacity500 GB750 GB750 GB750 GBRow 22 - Cell 5
Rotation Speed7200 U/Min7200 U/Min7200 U/Min7200 U/MinRow 23 - Cell 5
Platter3444Row 24 - Cell 5
Cache816816Row 25 - Cell 5
Native Command Queuing (NCQ)yesnonoyesRow 26 - Cell 5
InterfaceSATA/300Ultra ATA/100Ultra ATA/100SATA/300Row 27 - Cell 5

The versions with 250 and 320 GB utilize two platters, the 400 and 500 GB capacity points are based on three platters, and the 750 GB top model uses four platters. Only the 750 GB top model actually utilizes the maximum per-platter capacity of 190+ GB. The following table lists what the waste capacity is for each model.

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Barracuda 7200.10Theoretical Capacity MaximumWaste in GBWaste in %
250 GB, 2 Platter332 GB82 GB25%
320 GB, 2 Platter332 GB12 GB3%
400 GB, 3 Platter570 GB170 GB30%
500 GB, 3 Platter570 GB70 GB12%
750 GB, 4 Platter750+ GB-0%