The XE line of processors has undergone some radical changes over the past year. It started out as having a different core structure than the mid-line CPUs, and then it got an L3 cache to set it apart from the new Prescotts that came out. At the time, two differences (core structure and L3 cache). Intel then strove to change that once again and consequently introduced a 130nm model running at 3.46GHz with their fastest bus speed yet at 1066MHz (1.07GHz). Yet again, adding to the XE’s differences from their mid-line consumer processors. Then the assimilation began. The next XE processor ran faster at 3.73GHz, still sporting the 1.07GHz FSB, but it no longer was unique. It now sported the 90nm manufacturing process, but no L3 cache. Its only big difference was its bus speed which Intel said would be the difference between the XE line of processors and their mid-line (currently the 600 series). Now we see that the XE processor has lost its only really unique feature and is now almost identical to a 660 with the exception of the number of execution cores.

How hot does this chip get?
The 840 is the second processor that has gotten my complete and possibly excessive attention because of its temperatures. While it isn’t as bad as the original Prescotts (dubbed “space heaters?by some), it is still enough that I was concerned for some time.

Idle Temperature (C) Stress Temperature (C) Intel 840 44 67 Intel 3.73 XE 51 67 Intel 660 38 57

I was quite surprised to see the 840 actually idle lower than the 3.73 XE just because of the dual cores on the single-die. Unfortunately, a low idle doesn’t come without a high stress temperature at a whopping 67 degrees which is, in my mind, a little too high.

Test System Specifications
Only the best equipment can be used to test a chip like this and so I got all my best stuff together and crammed it all into one case.

Motherboard Intel 955XBK Processor Intel 840 Memory 2 x 512MB Corsair PC2-5400 CL4 HDD 300GB Maxtor DiamondMax 10 Sound Card On-board Graphics Card nVidia GeForce 6800GT CPU Cooler Stock Intel air 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 with 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.

The CPU tests show the largest improvement in performance. The dual-core 840 beats out the competition with HyperThreading Technology (HTT) enabled, but it does fall a bit short without it (operating with only two process threads). There are some higher numbers here, but nothing that doubles its single core equivalent.