Intel Core i7 and X58 Review

We got our hands on an Intel X58 motherboard and a Core i7 Extreme edition (3.2Ghz) processor. It has been a while since I had been even mildly excited about a new processor. Intel’s Conroe (in 2006) was probably the last one that got my attention. However, the Core i7 marks a new step in Intel’s line up for two main reasons: an emphasis on per-core performance and a push for “efficiency” that ultimately leads to performance gains.

The race to higher frequencies (Ghz) has been over since the Pentium 4 days. Frequencies will continue to increase at a slow page, but there’s definitely more “performance per clock” that can be squeezed out. For example, Hyper Threading (HT) returns with Core i7. It’s a technique (first introduced at Intel in 2005) that attempts to utilize all parts of the processor by making each CPU core appear to the operating system (OS) as two physical cores. The Core i7 shows up as an 8-core system to Windows. Hyper Threading can yield large performance gains, espcially in regards to the small cost that it generates in terms of number of transistors and power consumption (5%?).

Back to the Core i7 “per-core” performance: because many applications don’t process data in parallel, they don’t take advantage of multiple cores. They get executed on one core, while the others sit around almost idle. Core i7 is capable of adjusting its power consumption and frequency of a particular core to get a extra performance boost and this is good for virtually every application. When not much is going on, the CPU reduces its frequency to lower consumption and head dissipation.

Here’s our test configuration:

  • Intel Core i7 Extreme 965 (“Bloomfield”), 3.2Ghz
  • X58 Chipset
  • Western Digital Raptor 10k rpm 300GB
  • NVIDIA graphics card (no graphics tests involved)

Synthetic benchmarks have leaked a long time ago and they establish that the Nehalem architecture is significantly superior to its predecessors. But here is some interesting information not always covered by benchmarking sites:

Core i7 is adjusting its clock all the time. Using CPU-Z we can see that the core clock goes from 1.6Ghz (underclock) up to 3.33Ghz (overclock) depending on the workload. In theory, it switches pretty often and by often we mean that in between key strokes, the CPU powers down. It would be interesting to compile an average clock frequency in a typical day of use.


We set the CPU cooler so that it stays nearly silent. The fan on the cooler was spinning at 1300rpm, which is relatively low. The idle CPU temperature was about 35c, but during stress tests, it could reach: 68c (core0), 65c (Core1), 64c (Core2) and 61c (Core 3). It’s hot, but not unreasonnable. With a more aggressive cooling, the CPU should be able to reach 4.0Ghz in my opinion (try at your own risk!).


  • $999 Core i7-965 (3.2Ghz)
  • $562 Core i7-940 (2.93Ghz)
  • $284 Core i7-920 (2.66Ghz)


If you are building/buying a new system, it would be foolish not to wait for the Core i7, especially the 920. It will outpace current processors by a good margin, within the same price range (Core 2 Extreme, Core Quad 9400), especially in compute or memory-bandwidth intensive applications (3D rendering, compression…). If you’re seeking for absolute CPU performance, it has always been easy: just get the most expensive one ;)

But if you have a decent processor today, should you upgrade? Not so fast. Take a good look at what you’re doing and try to figure out how much the CPU would actually help. Don’t forget that this new platform requires a new motherboard and new memory (expensive DDR3). You might even have to get a new cooling system and a good power supply with the latest power connectors. If you want to refresh an existing computer, adding up to 3GB of memory (6GB or 8GB if you have a 64-bit OS) and a very fast hard drive will go a long way.

Core i7 is a significant step forward for Intel, one that will put AMD in an even more difficult financial position. I can’t wait to see the laptop version of this architecture.

Links: if you must see pages upon pages of synthetic benchmarks, here are my recommendations:Techspot, HardOCP. Tom’s has an interesing article about the differences between Core i7 and older architectures.

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