HP RX4640 Dual Port PCI-X 1000T Gigabit NIC - Server Backbone Adapter

Our review of the HP RX4640 Dual Port PCI-X 1000T Gigabit NIC finds it aimed squarely at server administrators and IT teams that need reliable, high-density Ethernet connectivity. The single biggest reason to consider this adapter is its combination of dual ports and 1Gbps capability on a PCI-X 64-bit/133MHz interface, which preserves valuable I/O slots while delivering backbone-level throughput. In short, this card is a practical choice when upgrading servers to gigabit networking without reworking existing chassis or cabling.

Key Features

• Dual-port design: Two gigabit ports on one adapter let administrators increase port density while saving PCI slots for other functions.
• PCI-X 64-bit/133MHz: The PCI-X interface provides a robust server-class connection and remains compatible with traditional PCI slots for broader deployment options.
• 1Gbps transfer rate: Native gigabit throughput supports server-to-server backbone traffic and high-bandwidth applications with minimal bottlenecking.
• 10/100/1000Mbps compatibility: The card works with legacy Fast Ethernet wiring as well as modern Gigabit networks, easing mixed-environment rollouts.
• Onboard memory: 128KB of onboard memory helps maintain steady data paths and offload some processing from the host CPU for sustained transfers.

Who It's For

The RX4640 is best for small to mid-size data centers, rack servers, and enterprises that need dependable server-to-server backbone connections at gigabit speeds without reconfiguring chassis or switching backplanes. It is also suitable for organizations migrating from 100Mbps to 1Gbps who need backward compatibility with existing cabling.

Administrators who require the absolute latest offload features or 10GbE and beyond should look elsewhere; this card is focused on stable, cost-effective gigabit Ethernet and assumes use in servers with PCI-X or legacy PCI slots.

Pros & Cons

Pros

• Dual ports maximize port density and reduce the number of expansion cards required in a server.
• PCI-X 133MHz interface offers a server-class connection and broad compatibility with many older systems.
• 1Gbps capability and 10/100/1000Mbps support allow use across both legacy and current Ethernet infrastructures.
• 128KB onboard memory helps maintain consistent throughput under load.

Cons

• Not suitable for networks that require 10GbE or higher speeds; limited to gigabit-class bandwidth.
• As a PCI-X card, modern servers with only PCIe slots will need adapters or different NICs for direct compatibility.

Specifications

Product	RX4640 Dual Port Gigabit NIC
Brand	HP
Ports	2 x 10/100/1000Mbps
Interface	PCI-X 64-bit / 133MHz (PCI compatible)
Onboard Memory	128KB
Typical Use	Server-to-server backbone and high-density I/O

Our Verdict

The RX4640 is a sensible, cost-effective choice for teams that need reliable gigabit networking and higher port density in servers that support PCI-X or legacy PCI. It delivers steady 1Gbps performance, backward cabling compatibility, and useful onboard memory, making it good value for upgrades where 10GbE is not required.

Frequently Asked Questions

Is this card compatible with standard PCI slots?
Yes, the adapter is PCI-X 64-bit/133MHz and is designed to be compatible with many traditional PCI slots, though performance is optimal in PCI-X slots.

Can this card be used on modern PCIe-only servers?
Not directly; modern servers with only PCIe will require a different NIC or a bridge solution, since this is a PCI-X form factor.

Does it support both 10/100 and 1000Mbps operation?
Yes, the card supports 10/100/1000Mbps, allowing it to operate on legacy Fast Ethernet wiring as well as Gigabit networks.