Intel Core i5 750 Core i7 870 Reviewccokeman - September 7, 2009
Price: Core i5 750 $196, Core i7 870 $562
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At launch there will be three different socket 1156 processors code named "Lynnfield". The i7 870 and 860 with the i5 750 one step down. The P55 chipset and Core i5/i7 socket 1156 combo is meant to bring Nehalem technology down to the mainstream level. Mainstream usually means that the impetus is to deliver a product for the masses or an economical solution. So how do you do this? Well for one you eliminate the Northbridge and incorporate its function into the CPU so that you are only using a 2 chip solution. By integrating the discrete graphics responsibility to the CPU as well as the memory controller you effectively eliminate the need for the additional chip. Therefore less money to build means the less you have to charge the consumer. With the costs associated with Nehalem ownership, the price of admission is still on the steep side when compared to the AMD camp. So you bring the price down for the masses and try not to shorcut features and performance to reach a more palatable price of entry. In these tough economic times the disposable income available for a new system is harder to come by with people wanting more for less. With AMD already a few steps ahead on the cost for performance front the P55 chipset and Lynnfield processors look to take them to task and take back the mainstream. To do this Intel has brought out the socket 1156 i5/i7 processors that feature the i5 750 with a clock speed of 2.66 GHz, Nehalem architecture, dual channel memory support, Turbo technology, 8MB of Smart cache and support for dual graphics cards in a 8x x 8x configuration with a 95watt TDP. The 8 series i7 870 and 860 contain all of the features of the i5 but run at 2.93GHz/2.80GHz and uses Hyperthreading technology while still having the same 95 watt TDP. At 2.8 GHz the i7 860 looks to be a a worthy successor to the i7 920 that has been so successful. Looking at the block diagram below you can see that the Nortbridge is a thing of the past. Just how will this new solution to fit into the the mainstream market? Will it be the next best thing since sliced bread or will it fall a little short of average? If early pricing reports are correct AMD could be in for a long year if the performance potential is reached.
What arrived for testing the new i5 and i7 socket 1156 processors was a kit that included the DP55KG "Kingsberg" Extreme series motherboard, A new heatsink from Thermalright the MUX-120 and a pair of processors. These being the Core i5 750 and the i7 870. The 870 came sans retail heatsink while the 750 came with a factory Intel heatsink. With the inclusion of the stock and aftermarket cooling options you can test both stock and overclocked performance. All in all a really nice kit.
The processors I will be looking at include the Core i5 750 that is a Quad core processor that runs at 2.66GHz and does not count hyperthreading in its list of attributes. It reaches this speed much the same way as the i7 920 does with a bclock of 133MHz with a clock multiplier of 20. The Core i7 870 runs at 2.93 GHz and reaches this speed using a multiplier of 22 with the bclock of 133Mhz for a slightly faster clock speed. While the i5 750 does not feature Hyperthreading the i7 870 does. The Lynnfield processors both come in at the same size and transistor count at 296mm2, 774M respectively. When you think Nehalem you think massive. By showing the i5 and 8 series i7 together with an i7 920 you can get an idea of just how much smaller the socket 1156 CPU's are by comparison.
One thing that was a shock was when I opened the box containing the i5 750 and the socket 1156 heatsink. The heatsink look's much like the low profile ones that come with the 65watt TDP socket 775 CPU's. As a reference I compared the size of the heatsinks(left to right) that came with my Q9450, i7 920 and the i5 750. Even though the TDP is 95 watts you would look for something a little more robust.
Thankfully Intel chose to include a high end air cooling solution in the MUX-120 from Thermalright to make sure that the overclocking testing can go off without a hitch. At first glance the MUX-120 looks like the TRUE but .....smaller. This cooling solution uses four heatpipes to transfer the thermal load from the contact plate to the fin array. The MUX-120 uses a fin array that contains 48 fins that are offset from the left to right side as well as having a small twist up or down on each end. Thermalright has included a PWM controlled fan that has a range of 1000 to 1800 RPM. The one thing that is a disappointment is the use of push pins to attach the heatsink to the motherboard. I guess this makes it easier for the masses that seem to dislike a bolt on heatsink.
The processor is only half of the new package from Intel. The P55 chipset and motherboard are the next piece that makes this performance puzzle complete.