Intel Lynnfield; Core i5 750 and Core i7 870 Evaluation

The launch of the new Lynnfield CPU and the P55 chipset from Intel has possibly been one of the worst product launches in Intel history. I am not saying the CPU is bad, in fact I would say just the opposite about the performance of the LGA-1156 CPUs.  However what has impacted the launch is that despite an NDA that did not lift until today, people have been buying both the Core i5 and Core i7 for LGA-1156 Socket in stores all over the world. Add to this a large influx of P55 motherboards that are on the shelves and you have a disastrous launch.  There is also the problem of the new naming convention. This little problem has been talked about at length and is, oddly enough, a large issue with many potential purchasers.

The problem as I hear it is with the Core i7 Lynnfield. You see for the most part when people think of Core i7 they will think LGA-1366 and X58. So the new Core i7 870 will seem to fall into that higher [and more expensive] category. However, while the naming is confusing, for us the performance differences were spot on and fit with the Intel marketing plan of putting the i7 870 as the high-end of the mainstream and dovetailing with the enthusiast level i7s.

In the pages below we will take a look at both the Core i5 and Core i7 Lynnfield CPUs. We will see how they perform at stock and what we can get from a quick overclock on air. Read on to see if this new CPU and chipset from Intel are worth your hard earned money.

What’s New
The biggest difference between Lynnfield and Nehalem [Core i7-900 series] is memory support. With Core i7 900 you get a full three channels but are limited to 1066 MHz for DDR3 support [at least that's the official line, which we all know is the other BS, opposite of Bright Side]. Lynnfield cuts the channel support back to two and increases the official memory support to DDR3-1333. The removal of the Triple channel support does change the socket as the pin count drops from 1366 to 1156. Not having triple channel memory will hurt memory intensive applications like rendering and in some case high-level computations. This is not a signification issue as Lynnfield is not marketed for those high-end applications but more for mainstream gaming and work.

From there Lynnfield breaks down into a couple of sets; we have the current Flagship Core i7 and the mainstream Core i5. Although the Lynnfield Core i7 will only have dual channel support it will still carry the i7’s Hyper-Threading which allows two threads per core to run each CPU cycle.

Click to Enlarge

Core i5 will lose Hyper-Threading but will maintain all of the other features found in the Core i7 870 although it will have a much slower clock speed. All three of the 1156 Lynnfields will have 8MB of L3 cache, an integrated memory controller, and a 95 Watt TDP. 

Lynnfield is also smaller, and more power efficient than both the 1366 Core i7 and the previous Core 2 Quad generation. In fact comparing clock for clock the core i5 is roughly 20% faster than a Core 2 Quad [i5 750 Vs. Core 2 Quad Q9400]. But the size difference is also important; Intel has moved the graphics controls onto the CPU. This means that your PCIe graphics are executed on the CPU rather than in the MCP or Northbridge. It allows for an overall reduction of silicone by about 40% compared to the older Core 2 systems.

Both the Core i5 and Core i7 LGA-1156 CPUs are very impressive on paper, they take some of the best features of the Intel Nehalem architecture and put them into a low(er) cost package. This should shake up the AMD claim that they have the best performance/price point. But as we have not covered performance just yet we cannot say that for certain.