NAS 7825, Next Generation Media Networked Storage Solution

© PLX Technology, www.plxtech.com

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1/4/2010, Version 1.0

PLX NAS 7825 brings a new architectural

approach to consumer NAS system on a chip

(SoC)

For years the conventional approach to SoC design

has been the bigger hammer approach. To improve

the performance, increase the clock speed of the

processor. This approach has not been unique to the

consumer NAS market but more of a general

semiconductor industry approach.

The PLX 7825 changes the game by a holistic view of

the overall system architecture. It uses the PLX

Trident architectural approach:

Figure 1: Trident Architectural Approach

1. Processor still is a key part of the overall

architecture. However, the new applications,

particularly the media applications, have unique

and stringent requirements such as low jitter and

high QoS. The common single core processors

simply cannot meet these requirements effectively

regardless of how fast the processor clock is

running. On the other hand, the dual core

architecture has significant advantages in:

Simultaneously running multiple applications

Performance intensive applications

Multi-threading kernels such as Linux

Flexibility in processor resource allocation.

For example, each core could be dedicated to

specific application or load-sharing and

balancing

Independent I & D cache reduces cache

pollution improved power/performance ratio

particularly in media application processing

2. Application specific hardware offload engine. The

PLX NAS 7825 has taken this approach to the

next level. By analyzing the performance funnel,

and indentifying the key areas and applications

with intensive processing requirement, the

product has implemented hardware engines to

relieve the processor and the internal bus from

intensive processing and system traffic. Hence

this improves the overall system performance

with better processor utilization (i.e., higher

throughput per CPU clock) reduces internal traffic

within the SoC, and better cost structure due to

less processor demand. PLX NAS 7825 utilizes

hardware offload engines in networking, security,

and storage (i.e., RAID & SATA) areas.

3. What integrates all the sub-systems together as a

cohesive system is restructured firmware. The key

design criterion is to fully utilize and bond all the

system hardware via highly optimized firmware.

Simply said, optimized firmware to utilize

hardware modules. This is the most challenging

part of the overall system architecture. The PLX

NAS 7825 has taken this approach to the next

level by providing the industry’s highest

optimized firmware for consumer storage.

Figure 2: NAS 7825 architecture overview

Enabling innovation and expansion into new

markets

The concept of networked storage is expanding into

many other consumer devices such as

routers/gateways, set-top boxes, and PVR/DVRs.

These new devices need to take additional roles over

traditional NAS. For example, they need to provide

routing, access point services, VoIP, NAT to name