The day has finally come, as we officially unveil Intel’s worst keep secret, the LGA1156 platform featuring the new P55 chipset, along with two new Core i7 and a single Core i5 processor. Over the past month or so the internet has been flooded with P55 motherboard images as everyone geared up for the arrival of the mainstream 1156-pin processors.

Intel’s first attack wave will be lead by the Core i7 870 and 860 processors, which are based on the same design as the LGA1366 Core i7 processors, making them an interesting addition to this cut down platform. However it is really the Core i5 750 processor that everyone is interested in. This is because it boasts similar specifications to the Core i7 920, with the exception of Hyper-Threading technology, which is absent.

More over, the new Core i5 750 processor will cost just $200 US, making it cheaper than the Intel Core 2 Quad Q9550, while it will match the current AMD Phenom II X4 955 Black Edition pricing. Clearly just $200 US is an unbelievable price for a quad-core processor that should blow both the Core 2 Quad Q9550 and Phenom II X4 955 out of the water, if the Core i7 920 performance is anything to go by.

The Core i5 750 processor is based on the Lynnfield (45nm) architecture and features a core clock speed of 2.66GHz with a maximum turbo frequency of 3.2GHz. Therefore the Core i5 750 matches the operating frequency of the Core i7 920, while it also boasts a large 8MB L3 cache. However unlike the Core i7 920, the new Core i5 750 is only designed to utilize dual-channel DDR3-1333 memory, where as the Core i7 900 series makes use of a triple-channel memory controller.

In order to cut the cost of this processor and the LGA1156 platform down, Intel has removed one of the memory controllers and replaced the high bandwidth QPI link with the slower DMI chip-to-chip interconnect. This means that the key difference between the Core i5 750 and the Core i7 920 processors will be the memory controller and the bus that connects the processor to the chipset.

The Core i5 750 is the first mainstream Intel processor built using the Nehalem architecture, and at just $200 this is an exciting quad-core part. The other quad-core processors being released today include the Core i7 870 and 860, which do feature Hyper-Threading for 8-threaded performance. However with a retail price of $285 US for the Core i7 860 and $555 for the Core i7 870, they are not exactly cheap.

The Core i7 860 will come clocked at 2.80GHz (3.46GHz Turbo), while the Core i7 870 will hum along to the tune of 2.93GHz (3.60GHz Turbo). Both are identical to their Core i7 900 counterparts, with the exception of the memory controller which only supports dual-channel DDR3 memory, and of course the use of the slower DMI chip-to-chip interconnect.

Using MaxxMem² we are able to measure the read and write performance of each configuration and there are a few interesting results here. Clocked at 2.93GHz, the Core i7 870 processor delivers roughly the same memory bandwidth as the Core i7 920, which is clocked at 2.66GHz using triple-channel memory.

The Core i5 750, which is also clocked at 2.66GHz, is considerably slower in terms of bandwidth when compared to the Core i7 920. Still, with a read result of 11.6GB/s and a write result of 9.5GB/s, it has considerably more memory bandwidth at its disposal when compared to the Phenom II X4 965 and Core 2 Quad Q9650 processors.

Looking further into the MaxxMem² results we also recorded the latency in nanoseconds and the average time it took to complete each test in seconds. As you can see, the latency is quite high when using the Core 2 Quad Q9650 processor, while the Phenom II X4 965 and Core i5 750 are very similar. Then the Core i7 860/870 and 920 processors all deliver much the same result, while the 960 is by far the best performer here.

Finally, to confirm that the MaxxMem² results are accurate, we double check with EVEREST Ultimate Edition, which did show similar performance trends. Again the Core i5 750 is considerably faster than the Phenom II X4 965 and Core 2 Quad Q9650 processors. Furthermore, the lower clocked Core i7 920 processor did provide more memory bandwidth when compared to the Core i7 870 processor, as it has the advantage of utilizing a triple-channel memory controller.

MaxxPI² is a great benchmark for measuring processor performance and it can be used to measure single-thread and multi-threaded performance. Interestingly the AMD Phenom II X4 965 has issues with the single thread test, while its multi-threaded performance is stellar, and for a quad-core part the single thread performance does not add up.

Nevertheless, what we do find is that the Core i5 750 processor is faster than the Core 2 Quad Q9650 despite being clocked significantly lower. The Core i7 860 is only slightly faster than the Core i5 750 processor despite having a total of 8 threads at its disposal. That said, the Core i7 860 is able to match the performance of the Core i7 920 processor, while the Core i7 870 is faster.

Now we are going to look at how the MaxxPI² calculation times translate into throughput. The single thread performance of the Core i5 750 processor is just a fraction less than that of the Core i7 860. Furthermore the Core i7 860 is just a fraction slower than the Core i7 920 processor. Despite the difference in clock speed and the memory controller disadvantage, the Core i7 870 is able to deliver roughly the same performance as the Core i7 960 processor in the mutli-threaded test.

When testing with WinRAR we see that the Core i7 870 is slightly faster than the Core i7 920, while both are much slower than the Core i7 960 processor. The Core i5 750 performed well, as it is just a fraction slower than the Core i7 860, while it is considerably faster than the Phenom II X4 965 and Core 2 Quad Q9650 processors.

For our real-world application testing we have selected Microsoft Excel 2007, which will be using a rather complex spreadsheet to gauge the performance of each configuration. Something worth pointing out here is that the AMD Phenom II X4 965 is the best performing processor in this test, which is not something we were expecting to see. The Phenom II X4 965 is able to complete the test within 11 minutes, along with the Core i7 960 and 870 processors.

The Core i5 750 is considerably faster than the Core 2 Quad Q9650, shaving just over 2 minutes off the completion time. This made the Core i5 750 roughly the same speed as the Core i7 860 and 920 processors in this test, which is impressive.

Using WinRAR we measure the time it takes to compress certain files. For the first test we compress the entire Windows 7 installation to a single file and measure the time it takes. A similar thing is done for the second test, though here we compress just a single large 12GB file. The Core 2 Quad Q9650 for example took 14:57 minutes to compress the Windows 7 installation and 67:54 minutes for the 12GB file.

The Core i5 750 processor is able to improve on the performance of the Core 2 Quad Q9650 considerably, taking just 9:52 minutes to compress the Windows 7 installation and 42:50 minutes to compress the 12GB file. The Core i7 920, 870, 860 and Core i5 750 processors all took at least 42 minutes to compress the 12GB file, while the Core i7 960 did it in just 37:33 minutes.

Using a high resolution image we measure the time it takes for each processor to apply two Photoshop filters, the smart blur and extrude filters to be precise. Again the AMD Phenom II X4 965 processor is surprisingly fast, as it applied the smart blur filter the fastest. That said, it did struggle with the extrude filter, though it is just a second and a half slower than the Core i7 920 processor.

The Core i5 750 matched the Core i7 860 processor, which is impressive given that it lacks Hyper-Threading technology and its clocked 140MHz lower. The Core i7 870 performance is also impressive, as it is only a fraction slower than the Core i7 960 processor.

FurMark shows that all the tested processors are able to max out the GeForce GTX 285 graphics card at 1024x768. The minimum frame rate, which is more dependent on the CPU, shows the Core i5 750 delivering average performance as it is slower than both the Core 2 Quad Q9650 and Phenom II X4 965 by quite a margin. Interestingly the Core i7 920, 870 and 860 processors are also limited to 101fps.

The Unigine Engine tests are clearly GPU oriented, as the processor makes little difference in the Sanctuary and Tropics tests. For example the Core i5 750 processor delivers roughly the same performance as the Core i7 960 processor.

The SPECviewperf tests are more CPU dependent, and while the Core i5 750 is slightly slower than the Core 2 Quad Q9650 for the 3dsMax test, it is significantly faster when testing with Maya. In fact, the Core i5 750 is successively reported to be a little bit faster than the Core i7 920 processor in the Maya test. The Core i5 750 and Core i7 860 processors deliver virtually the same performance in this test.

Although the Unreal Tournament 3 results at 1920x1200 place little difference between the slowest and fastest processors tested, the 1024x768 results are more interesting to compare CPU performance. The Intel Core 2 Quad Q9650 manages 225fps, the AMD Phenom II X4 965 fires off 263fps. Then the Core i5 750 is able to average 268fps, making it slightly slower than the 273fps of the Core i7 920.

At 1024x768 the Intel Core 2 Quad Q9650 manages 183fps in Street Fighter IV, which would sound impressive if the Phenom II X4 965 wasn't scoring a whole lot better at 226fps. The Core i5 750 is faster again with 236fps, which is about the limit of the graphics card as the Core i7 processors produced similar results.

Finally we have Far Cry 2, which we like to use as a gaming test platform because it is very demanding on both the GPU and CPU. As a result, even the 1920x1200 results differ quite a bit from processor to processor. When testing at this high resolution the Core 2 Quad Q9650 averages 67fps, while the AMD Phenom II X4 965 is a bit faster at 70fps. The Core i5 750 scores a single frame per second better (71fps). The Core i7 processors did provide a slight performance advantage over the Core i5 750 in this game.

The power consumption levels for the Core i5 750 processor and the new P55 chipset are very impressive. At idle our Core i5 box consumes 106 watts, while increasing to 198 watts under load. Compared to the equally clocked Core i7 920, the Core i5 750 is far less power hungry. Compared to older platforms, the Core i5 750 uses less power than even the Core 2 Quad Q9650, making it one of the most efficient platform and processor by far in our tests. The Core i7 860 and 870 processors are also incredibly efficient.

That said, with the Core i7 920 priced at $280 US, we really have no idea why the Q9650 still exists, though clearly it won’t for much longer. The Phenom II X4 965 is AMD’s current flagship desktop processor, and at $240 US it is exceptional value. However at just $200 US the Core i5 750 is even better value, as it is found to be even faster in quite a few tests.

For us the Core i5 750 processor has been a sigh of relief, as we were initially quite unimpressed that Intel decided to release yet another entirely different platform, despite being well aware of their plans before the LGA1366 platform was even released. Given that the Intel X58 chipset does very little, we saw no reason why the P55 could not have supported the LGA1366 socket, allowing consumers to choose between the affordable Core i5 series or the full-blown Core i7 series.

Now instead, we have two different sockets supporting different processors, and in no way are they cross compatible like the new AM3 processors are with the older AM2/AM2+ sockets. Furthermore, we have two Core i7 series that are almost identical, even in price. This makes the Core i7 800 series in our opinion quite pointless, as the Core i7 860 costs exactly the same amount as the Core i7 920 processor, while the later is faster in the majority of tests.

Both the Core i7 920 and 860 are very much the same processor with the key difference being the memory controller, for which the 920 utilizes a triple-channel design opposed to the dual-channel design of the 860. EVEREST reports that the Core i7 920 has around 13% more bandwidth at its disposal, which appears to make up for its 5% clock speed disadvantage.

At the end of the day, the Core i7 920 will set you back about $20 - $30 US more in DDR3 memory if you go for a 6GB triple-channel kit over a 4GB dual-channel kit, while a P55 motherboard could be anywhere from $50 - $100 US less. Therefore, a Core i7 860 system stands to save you a little over $100 US by our calculations, which in the big picture is stuff all.

After all, you are sacrificing 2GB of memory, the ability to utilize six DIMM slots, and multi-GPU technology should you want to use it, along with a small amount of performance. While the P55 chipset does support SLI and Crossfire, a pair of PCI Express graphics cards will be limited to x8 bandwidth, which can limit performance when compared to the x16 bandwidth you will get with an X58 chipset.

That said, we are still very pleased with the new LGA1156 platform simply because the Core i5 750 is such a stellar processor at just $200 US. This new mainstream processor is the perfect step down from the Core i7 920, as it stands to save users around $250 US on their CPU/MB/RAM combo. Users should be able to get their hands on a Core i5 750 combo with 4GB of memory and a P55 motherboard for around $400 US, which is amazing given the power.

In short, not everyone needs the incredible power of a Core i7 900 series processor, in fact most of us don’t, especially those that spend much of their spare time gaming. This is what made the AMD Phenom II X4 series such a great alternative, as it was unbelievably cheap while being able to deliver the same exciting gaming experience as the more powerful Core i7 processors due to GPU limitations. The Core i5 750 fills the void nicely, and brings a great deal of competition of the Phenom II X4 range.

Although we only had a very short time to play around with the new Core i7 870, 860 and Core i5 750 processors, it was just possible to fit in some brief overclocking. Amazingly we were able to crack the 4.10GHz barrier with these processors. The Core i5 750 using the Prolimatech Megahalems reached an impressive 4.13GHz, while we squeezed 4.16GHz out of the Core i7 870 processor without much trouble.

In fact, these overclocks are some of the most successful we have ever had using air-cooling, and it is very likely that they were the easiest to achieve as well. The ease of these overclocks is likely thanks to the brilliant ASUS P7P55D Deluxe motherboard, which required us to change only the base clock frequency.

The voltage was raised, but the P7P55D Deluxe did this automatically without our influence. At its default operating frequency of 2.66GHz the Core i5 750 sucked down around 1.250v, while at 4.13GHz it required 1.550v, which the motherboard adjusted to automatically. Therefore we were able to achieve a massive 36% overclock using air-cooling by simply changing the base clock to 206MHz.

Overall we are very pleased with the Core i5 750 processor and the accompanying P55 chipset, which helped to make the ASUS P7P55D Deluxe such a great motherboard. The Core i7 800 series has us a little miffed, as we feel for the money users might as well build a Core i7 system the way it was meant to be, using the LGA1366 platform. For now we look forward to seeing Core i5 750 processors on shelves, along with P55 motherboards.

Reviewed By Steven Walton