Side-by-Side Processor Comparison
I have always liked seeing a comparison of one product against others to see how it stands up and if it stands out. Let’s take a look at how the Pentium 820 stands against its competition.

Intel Pentium D 820 Intel Pentium 840 Intel 3.73 XE Manufacturing Process 90nm 90nm 90nm Number of Execution Cores 2 2 1 Socket LGA775 LGA775 LGA775 Bus Speed 800MHz 800MHz 1066MHz Clock Speed 2800MHz 3200MHz 3730MHz HyperThreading Technology No Yes Yes L1 Cache 16KB 16KB 16KB L1 Trace Cache 12-k micro-ops 12-k micro-ops 12-k micro-ops L2 Cache 2 x 1MB (1MB per core) 2 x 1MB (1MB per core) 2MB L3 Cache N/A N/A N/A EM64T Yes Yes Yes Intel SpeedStep No Yes No SSE3 Instruction Set Yes Yes Yes Execute Disable Bit Yes Yes Yes

As you can see in the table above, the only differences between the Pentium 820 and 840 are the lack of HyperThreading Technology and the clock speed. Other than that, they are identical chips. When you compare this to the 3.73 XE you notice that the bus and clock speeds are the larger difference, but the 3.73 XE also lacks a second execution core, but it does have the HyperTheading.

How hot does the Pentium 820 run?
With the introduction of dual-core processors, cooling has become an even more important issue than ever before. The two dual-core processors that I have tested have displayed some excessively high temperatures, which I am sure are a result of the additional core.

Idle Temperatures (C) Stress Temperatures (C) Intel Pentium D 820 45 63 Intel Pentium 840 44 67 Intel 3.73 XE 51 67

The Pentium D 820 seems to run a little hotter than the 840 while idling, but on the other end of the spectrum, it also runs about four degrees cooler than the 840.

Test System Specifications
Naturally, I used the latest hardware available to me to test this little chip out. Putting it through its paces is never a difficult task as long as you have some serious gear with you. Here is what I used today:

Motherboard Intel D945GTP Processor Intel Pentium D 820 Memory 2x 512MB Corsair PC2-5400 CL4 HDD 300GB Maxtor DiamondMax 10 Sound Card On-board Graphics Card On-board Power Supply Unit ThermalTake Silent PurePower 680W CPU Cooler Stock Intel Cooler Operating System Windows XP Professional x64 Edition Software Latest motherboard drivers DirectX 9.0c nVidia nForce 71.89

Benchmarks Performed
I performed the following benchmarks on the systems to see how efficient the processor was at its job. Below is a list of programs and benchmarks performed.

• SiSoft Sandra 2005 Professional
  o CPU Arithmetic
  o CPU Multimedia
  o Memory Bandwidth
  o Cache and Memory
• PCMark 2004 (rev.120)
  o CPU
• Science Mark 2.0
  o Molecular Dynamics
  o Blas SGEMM
  o Blas DGEMM

My Benchmarking Methods Explained
For all the benchmarks, I booted Windows in Diagnostic Mode to eliminate all unnecessary processes. This gives me a clean slate with which to work on and makes sure that Windows doesn’t decide to start sucking up resources during a benchmark. For the SiSoft benchmarks, I ran the burn-in wizard ten times to ensure that the benchmark would yield accurate results. For all other tests, I ran five trials and averaged the five scores.