"Lynnfield" is the name of the new family of CPU's from Intel - if you've been frothing at the lips over the Core i7 chips but haven't had the financial inclination to splash out on one then these are probably what you've been waiting for, given that they are being touted as the mainstream alternative to the more expensive LGA 1366 platform.

If you're confused about all the names and numbers floating around Intel CPU's and chipsets lately, let me explain everything in a nutshell. Firstly, all Core i5, i7 as well as future i3 and i9 CPUs are part of Intel's "Nehalem" microarchitecture, which is replacing the previous "Core" microarchitecture (which replaced the "Pentium" microarchitecture).

The quad core Core i7 CPU's that have been selling since last year are part of the Bloomfield platform, which use socket LGA 1366 motherboards. The new Core i5 and Core i7 CPU's that I will be showing you today are part of the Lynnfield platform, which use socket LGA 1156 motherboards. LGA 1366 motherboards currently use Intel X58 chipsets, while LGA 1156 use P55. Clear as mud? Good, let's continue.

So what's the difference between a Bloomfield Core i7 and a Lynnfield Core i7? Well firstly you can tell them apart by their model names - Bloomfield/LGA 1366 Core i7s have a 9xx naming convention (e.g. 920, 940, 965), while Lynnfield/LGA 1156 Core i7's use 8xx (e.g. 860, 870). As far as practical differences go, the Bloomfield platform uses triple channel memory compared to dual channel on Lynnfield, and is also capable of dual 16x Crossfire and SLI performance, compared to dual 8x. There are other technical differences, but from a gamer's perspective that is about all you need to know.

The Core i5 750 squeezes in here somewhere as well - this is also part of the Lynnfield/LGA 1156 platform. The only difference between this chip and a Lynnfield Core i7 is the fact that it does not support HT (Hyperthreading). HT means having 2 "threads" per physical core, good for multi-threaded applications. Games don't typically take much advantage of Hyperthreading so this cheaper part will be of interest to many budget-conscious gaming enthusiasts, I'm sure.

Specifications

Here are the main specs for the 3 Lynnfield chips on the block today, plus the older Core i7 that I'll be putting them up against:

The "stock speed" isn't actually what you'll find these chips running at very often. Unless you manually tinker with your BIOS settings, the CPU's will automatically adjust their speed up or down depending on how heavily you're using them. During idle moments, the speed and voltage will drop significantly, resulting in lower heat output and power usage. Then, when stress is put on the CPU, "Turbo Mode" will kick in and the chips will overclock themselves slightly. The Core i7 860 and 870 are supposed to clock themselves up to about 3.46GHz but I never actually saw this high in testing. The speeds that the chips generally ran at under load, as well as the memory speeds I've used for comparison are as follows:

• Core i5 750: 2.80ghz, dual channel DDR3-1333MHz CL9
  
• Core i7 860: 2.93ghz, dual channel DDR3-1600MHz CL9
  
• Core i7 870: 3.20ghz, dual channel DDR3-1600MHz CL9
  
• Core i7 965: 2.80ghz, triple channel DDR3-1333MHz CL9 (Core i5 750 + extra RAM channel + HT enabled)
  
• Core i7 965: 2.93ghz, triple channel DDR3-1600MHz CL9 (Core i7 860 + extra RAM channel)
  
• Core i7 965: 3.20ghz, triple channel DDR3-1600MHz CL9 (Core i7 870 + RAM channel)

The last 3 lines above are 3 different settings I've set my Core i7 965 to in order to gauge the performance benefit, if any, of the Bloomfield platform over Lynnfield, with the difference between the competitors listed in brackets.

Test system

LGA 1156 Mobo: Asus P7P55D Pro (supplied by PlayTech)
LGA 1366 Mobo: Asus P6T Deluxe V2 (supplied by PlayTech)
RAM: G.Skill Trident (supplied by PlayTech)
GPU: Asus 4870 Matrix 512mb
HDD: WD 250GB SATA II
Screen: Samsung 206BW 20" 1680x1050 LCD
O/S: Windows 7 build 7600 64bit

Next page: testing results, conclusion.