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Seagate

Seagate ST3400820AS 9BJ134-622 400GB 7.2K RPM 3.5" SATA internal hard drive

SKU CH-D578-NNAN1

A 400 GB desktop hard drive spinning at 7200 RPM with an 8 MB cache and a 3.5" SATA interface

  • 400 GB capacity stores large file collections
  • 7200 RPM spindle speed delivers responsive data access
  • SATA 3 Gb/s interface connects to standard desktop ports
  • 8 MB cache buffers bursts for smoother throughput
  • 5 inch form factor fits typical drive bays

400GB 7200RPM SATA 3Gb/s desktop drive

The Seagate ST3400820AS is a 400GB 3.5-inch internal hard drive spinning at 7200RPM with an 8MB cache. It connects through a SATA 3Gb/s interface and is supplied in new condition. This unit suits desktop PCs that need a traditional mechanical drive for secondary storage or legacy system repairs.

Suits older desktops and capacity-matched upgrades

This drive fits builds that specifically require a 3.5-inch SATA 3Gb/s drive with 400GB capacity and 7200RPM speed. It is not for systems that need higher capacities, larger cache buffers, or faster 6Gb/s SATA throughput. Buyers wanting solid-state speed or modern interface standards should look elsewhere.

SATA 3Gb/s interface determines compatibility

The single specification that decides fit is the SATA 3Gb/s interface; the motherboard or controller must support this standard for the drive to operate. The 3.5-inch form factor requires a standard desktop drive bay and matching power and data cables. Verify both interface and physical mounting before purchase.

Highlights

  • 400 GB capacity stores large file collections
  • 7200 RPM spindle speed delivers responsive data access
  • SATA 3 Gb/s interface connects to standard desktop ports
  • 8 MB cache buffers bursts for smoother throughput
  • 5 inch form factor fits typical drive bays

Specifications

No published specifications for this item yet.

Questions about this item

How do I install the 3.5" SATA drive and which step is often missed?

Mount the drive in a 3.5" bay, connect the SATA data cable to a 3Gb/s port and attach the SATA power connector; the step often missed is ensuring the motherboard SATA controller is set to AHCI mode in BIOS before the OS loads.

What maintenance or replacement will the ST3400820AS need later?

No routine maintenance is required; the drive will eventually need replacement when the 7200 RPM motor or 8 MB cache controller wears out after years of continuous operation.

What limit appears first during sustained transfers on this 400GB drive?

The 3Gb/s SATA interface bandwidth becomes the bottleneck before the 7200 RPM platters or 8 MB cache can be fully utilised during long sequential reads or writes.

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