In recent months, we have seen Intel and AMD battle it out to be the first one to the market with a dual-core, single-die processor. With both companies introducing their first dual-core processors for the consumer market, we are seeing some changes in the personal computing concept with a workload going from simple single tasks and single threaded processes to very intense multi-threaded tasks. Intel came out punching on the dual-core path with their pride and joy, the Pentium 840 Extreme Edition processor that not only had dual-cores, but also supported Intel's HyperThreading Technology. The Pentium 820 is, in almost every respect, identical to the Pentium 840 with one exception, its lack of HyperThreading Technology. So is the 820 any good? Let's find out.

Table of Contents
Page 1: Introduction / Taking a closer look at the Pentium 820 / New and old technologies present in the Pentium 820
Page 2: Side-by-Side Processor Comparison / How hot does the Pentium 820 run? / Test System Specifications / Benchmarks Performed
Page 3: SiSoft Sandra Results
Page 4: ScienceMark Results / PCMark 2004 Results
Page 5: PCMark 2004 Results (cont'd) / Concluding Remarks

Taking a closer look at the Pentium 820
I have assembled a brief technical overview and a description of the technologies present in the Intel Pentium 820.

Processor Specifications
Speed: 2.80GHz
Manufacturing Process: 90nm
Socket: LGA775
Bus Speed: 800MHz
L1 Cache: 16KB
L1 Trace Cache: 12-K micro-ops
L2 Cache: 2x 1MB
L3 Cache: n/a
Core Voltage: 1.250V-1.400V (voltage deviation not included)
Bus/Core Ratio (Clock Multiplier): 14

New and old technologies present in the Pentium 820
With each new Intel processor has come new and innovative technologies, and the Pentium 820 is no exception. Although it doesn't have anything new over the Pentium 840, to its credit, it still bears relatively new technologies.

Dual Execution Core Structure
Intel dual-core products like the Intel Pentium processor Extreme Edition are well suited for multitasking environments because there are two complete execution cores instead of one, each with an independent interface to the front-side bus. The dual-core Intel Pentium processor Extreme Edition offers 1MB to each core exclusively, delivering the resources of two full processing cores, giving you the new capability to accomplish performance-intensive tasks on your PC.

EM64T (Extended Memory 64 Technology)
Intel?Extended Memory 64 Technology (EM64T) delivers the flexibility for operating systems and future software that support 64-bit computing. Intel processors with EM64T also bring the responsiveness of Hyper-Threading Technology into the 64-bit computing environment.

• As with any new technology, the emerging desktop platform 64-bit software ecosystem is expected to lag behind hardware readiness.
• Not all available 64-bit compilers are properly configured to take advantage of Intel Technology.

EM64T currently works and was tested with Windows XP Professional x64 Edition in the We labs.

Execute Disable Bit
Malicious buffer overflow attacks pose a significant security threat to businesses, increasing IT resource demands, and in some cases destroying digital assets. In a typical attack, a malicious worm creates a flood of code that overwhelms the processor, allowing the worm to propagate itself to the network, and other computers. Intel's Execute Disable Bit functionality, first released for the Intel?Itanium?processor family in 2001, can prevent certain classes of malicious "buffer overflow" attacks when combined with a supporting operating system. Execute Disable Bit allows the processor to classify areas in memory by where application code can execute and where it cannot. When a malicious worm attempts to insert code in the buffer, the processor disables code execution, preventing damage or worm propagation.

Execute Disable Bit currently requires one of the following operating systems to support it:

• Microsoft Windows Server 2003 x64 Edition
• Microsoft Windows Server 2003 with Service Pack 1
• Microsoft Windows XP Professsional x64
• Microsoft Windows XP with Service Pack 2
• SUSE Linux 9.2 
• Red Hat Enterprise Linux 3 Update 3

There are a number of fairly important older technologies in this chip as well and so I will not discount them. Below are few descriptions of the more important of these older technologies.

Advanced Dynamic Execution
The Advance Dynamic Execution engine is a very deep, out-of-order speculative execution engine that keeps the execution units executing instructions. It also includes an enhanced branch prediction algorithm that has the net effect of reducing the number of branch mis-predictions.

Streaming SIMD Extensions 3 (SSE3) Instructions
With the introduction of SSE2, the Intel NetBurst microarchitecture extended the SIMD capabilities that Intel MMX technology and SSE technology delivered by adding 144 instructions. The next generation 90 nm process-based Pentium 4 processor introduces the Streaming SIMD Extensions 3 (SSE3), which includes 13 additional SIMD instructions over SSE2. The 13 new instructions in SSE3 are primarily designed to improve thread synchronization and specific application areas such as media and gaming.

Level 1 Execution Trace Cache
The 90 nm Pentium 4 processor features 16-KB data cache compared to 8-KB on the 0.13 micron Pentium 4 processor. In addition to the data cache, the Pentium 4 processor includes an Execution Trace Cache that stores up to 12-K decoded micro-ops in the order of program execution. This increases performance by removing the decoder from the main execution loop and makes more efficient usage of the cache storage space since instructions that are branched around are not stored. The result is a means to deliver a high volume of instructions to the processor's execution units and a reduction in the overall time required to recover from branches that have been mis-predicted.