Intel Core i5 750 & i7 870 Review

Author: Pier-Luc Gendreau, Carl Poirier
Editor: Howard Ha
Publish Date: Monday, September 7th, 2009
Originally Published on Neoseeker (
Article Link:
Copyright Neo Era Media, Inc. - please do not redistribute or use for commercial purposes.

It has already been ten months since the first Core i7 chips were released, bringing processor performance to new heights. The QX9770 was no longer king of the hill, being replaced by the equally expensive, but much faster, Core i7 965 based on the full featured Nehalem architecture. The Bloomfield lineup proved to be excellent multithreaded performers, thanks in part to the return of Intel's HyperThreading technology.

Since then, Intel has been nearly silent in terms of launching new products. They quietly introduced a couple more Core i7s with updated core frequencies, thus replacing the 3.2GHz king by a 3.33GHz monster, named the Core i7 975. Without any doubt, this processor is the king of the hill when it comes down to raw performance. All that for a bargain basement price. Right now it can be yours for as low as a grand. Of course, there's the 2.66GHz Core i7 920 which comes in at a much more reasonable $280 USD.

That's where AMD comes into play. Their K10.5 architecture, as shown in most tests, cannot rival Nehalem parts at equal frequency. Being second in terms of performance, AMD has no choice but to offer very competitive prices, in function of the performance its processor delivers. AMD's flagship processor is sold for tad less than $250 USD. This might get the attention of anyone buying a computer on a budget, since the Core i7 platform is more expensive all around, from the triple channel memory kits to the X58 motherboards.

That's where the need for a mainstream oriented platform based on Intel's Nehalem architecture comes from. With the launch of the cheaper Core i5 and i7 processors built on the Lynnfield core, many people are hoping to finally get their hands on the bleeding edge toys. In fact, the Core i5 750, on launch today, sells for $199, whereas the i7 920 costs $279.99. What do you get for such a low price and are there also higher-end versions that might still be affordable? Let's take a peek at the specifications of the new Lynnfield processors.


  Intel Core i5-750 Intel Core i7-860 Intel Core i7-870 Intel Core i7-920
Clock Speed (Ghz)
Max Turbo Frequency (GHz)
Memory Speed Support
Memory Channels
Integrated PCI-E
Yes (1x16 or 2x8)
No (2x16 or 4x8)
Die Size
Transistor Count
Data Transfer Interface
Hyper Treading
Code Name
Processor Generation

New Intel Core Microarchitecture (Nehalem) 45nm

The first noticeable thing is that Intel allowed the maximum turbo frequency to scale much higher than with previous Core i7 processors. In fact, Lynnfield processors can bump their multiplier by up to five notches. The memory channels are down to two, however the memory frequency is the same and desktop computers aren't exactly starving memory bandwidth so it shouldn't have a large impact on overall performance, if any.

Another great innovation is that the PCI-Express 2.0 controller is now on the processor's die. It has 16 lanes, so it can run either one 16x or two 8x slots, although most manufacturers will opt for the latter in order to support two graphic cards in either CrossFire or SLI. The X58 chipset could handle up to four video cards, however, keep in mind that Lynnfield parts are targeted at a mainstream audience. Compared to the i7 9x0 series, the TDP dropped 35W, from 130W to 95W. Bloomfield's run hot so I am happy to see an improvement here.

Next, the die size and transistor count is a tad higher due to the integrated PCI-E controller. Also, on the X58 platform, communication between the processor and the northbridge is done using an extremely fast QPI link while Direct Media Interface, or DMI for short, is used between the north and southbridge. Since the PCI-E lanes are now directly on the processor, the need for bandwidth has been greatly reduced so Lynnfield dumps QPI in favor of DMI. Furthermore, the new platform now consists of a dual-chip solution - a processor connected directly to the platform controller hub, or PCH for short, which is the new fancy and admittedly more accurate name for southbridge.

Therefore, this compensates for the larger processor die size. In fact, the package size as a whole is reduced by 40% compared to a 45nm Core 2 Quad, P45 chipset and ICH10. The idle power consumption is also down by a rather impressive 50%.

The P55 chip is essentially what we used to refer as the southbridge. In fact, it is extremely similar to Intel's ICH10. The chip is highly integrated and contains a whooping 14 USB ports, 8 PCI-Express 1.0 lanes, Gigabit LAN, HD audio and six SATA2 ports.

Basically, new Core i5 and i7 parts based on Lynnfield core and accompanied by Intel's latest P55 chipset brings more performance and lower power consumption while keeping pricing in line with an AMD Phenom II based platform.

While Bloomfield was seemingly huge with its 1366 pins, reducing the number of pins down to 1156 allowed Intel to make a physically smaller processor. As you can see in the following picture, it is comparable in size to a socket 775 processor. It also has a few contacts on top of it, just like previous Bloomfield processors.

In fact, it is exactly same size as the LGA775 processors, although the contacts are much smaller and densely packed so they can fit in the same area. It's pretty impressive they were able to cram nearly 400 more pins on the same surface.

If you have ever seen a stock heatsink from a Bloomfied processor, you most likely noticed that it is much bigger than the one Intel made for 45m LGA775 processors. Now that the TDP is back down to a reasonable 95W, the same as a Core 2 Quad excluding the low power editions, the heatsink is also back to a thinner design.

Obviously, many aftermarket heatsinks from different manufacturers will hit the market in the near future in order to satisfy the enthusiast in each of us. As always, Thermalright products are up for the new challenge. To cool the new Lynnfield processors, we were provided the brand new MUX-120. Visually, it looks like the "TRUE", for Thermalright Ultra 120 Extreme, which is one of best air cooled heatsinks we've used. In order to reduce airflow restriction, the fins are slightly inclined toward the top or bottom, depending on the side. It is equipped with a fan generating between 35 and 66.5 CFM and spinning between 1000 and 1500 RPM while emitting a reasonable 19.6 to 37.4 dBa. As for the mounting system, Thermalright opted for push-pins. While it is without doubt simple and people may like this system for its easier installation, enthusiasts generally prefer a more robust mount with a backplate.

The motherboard provided by Intel with these new processors is the DP55KG, part of their Extreme series. On the back of the box, the motherboard layout is thorougly explained. It is also shown that the Lynnfield processors and the P55 chipset are a "Revolutionary Two-Chip Layout", much like the NVIDIA Ion platform. While we're talking about NVIDIA, the Kingsberg board is SLI-ready, unlike the first X58 motherboards. Most X58 motherboards are now SLI-certified and all of them, assuming they have the necessary PCI-E slots, support CrossFire. The vast majority of P55 boards should also support both CrossFire and SLI.

Looking at the motherboard, there is no doubt that one chip is apparently missing. While we are accustomed to see large northbridge heatsinks, this one simply has none, since well, there's no northbridge. The PCH chip fills the southbridge's role and has been located where we would normally find it. It is dressed with a tiny aluminum heatsink.

Starting in the top left corner, we have the usual processor power connector and its 4-pin fan header. The voltage regulators' heatsink isn't anything fancy, but it gets the job done. What's rather unusual here is the internal USB port. It works exactly like any other USB port. What can it be used for? Well, it's a clever spot for something to be left in there permanently like a thumbdrive or a WLAN module. It's up to you to find other great usages for it!

The memory slots are, as always. in the top right corner. There are four of them since the Lynnfield processors are back to standard dual-channel controllers. The ATX power connector is also at its usual place. Inbetween the two, at the top, is a small power button for those running open-air setups. On the side are USB, FireWire headers as well as the connectors for front panel buttons and LEDs. There's also another 4-pin fan connector.

Right under the PCH chip, you can find the eight SATA2 ports, the clear CMOS jumper and, dressed in green, the Bluetooth module. The skull actually works as a power LED and a HDD LED. When the computer is turned on, it is blue back-lit and its eyes can be set to blink according to the hard drive activity. This lighting can be turned on or off in the BIOS.

As for the expansion slots, there is only one full length PCI-E 16x. However, you can run a dual-graphics card setup since the lanes split in two 8x slots. Intel simply chose to put an open-ended 8x slot. There is also an open-ended x4 slot, as well as two 1x'. Two PCI slots have been kept for older legacy devices. Near them are two other 4-pin fan connectors and the front panel audio header.

Between the socket and the expansion slots is the CMOS battery and  a LED debugger, which can come in handy in some situations where the board refuses to successfully boot.

The I/O panel is comprised of a whooping eight USB ports, a single FireWire and Gigabit LAN ports, two eSATA and the usual six audio analog connectors. The innovations are the dual optical output and a button that allows you to recover a bad overclock. However, instead of simply clearing the BIOS settings, it forces the system to load default settings, while keeping your old ones so you don't have to start from scratch.

As for accessories, Intel supplies an arguably ghetto Bluetooth antenna. The actual antenna looks pretty bad and the standard UFL connector is far from ideal for a consumer product. However, it works very well and I had no trouble pairing a couple Bluetooth devices with it. There is also a SLI bridge as well as the rear panel connector and the mandatory manual.

Now that we have thorougly examined the socket 1156 platform, let's get to testing!

I will test two out of the Lynnfield processors released today : the Core i5 750 and Core i7 870. They will be put against the latest AM3 offerings from AMD, as well as Intel's Core i7 920 and two Core 2 processors. The AMD and Core 2 quad-cores have a raw clock speed advantage, however, the newest Lynnfield's can match or even best them with their secret weapon : Turbo mode. Therefor, I will test them with both this mode enabled and disabled in order to see the impact on overall performance.

As for the benchmarks, there will be a set of system benches and another set of gaming benches. Fraps will be used to record the FPS in both Call of Duty: World at War and Bioshock whereas for all other gaming tests, the built-in benchmarking tool will be used. All of these will be ran at 3 different resolutions except Call of Juarez, Lost Planet and World in Conflict where the minimum settings will be used to prevent a bottleneck from the graphics card.

Test Setups


Socket 1156 system #1:

Socket 1156 system #2:

AM3 system #1:

AM3 system #2:

Socket 775 system #1:

Socket 775 system #2:

Socket 1366 system:


Overclocking the new Lynnfield processors, in both i5 and i7 flavors, is not only similar, but actually identical to overclocking a Bloomfield like the Core i7 920. The processors have a base clock (BCLK), which the processor's core, uncore (integrated memory controller and cache) clocks and the memory derive their clock from. By default, it is set at 133 MHz.

Once processor limitations were put aside by lowering the multiplier, I set off to find the maximum BCLK the DP55KD could reach. While many of the X58 motherboard's could reach 200 MHz with relative ease, the sample Intel board  used in this review could only manage a measly 182 MHz. Past this speed, it showed obvious signs of instability, from corruption to blue screens and freezes. Fortunately, it only required 1.30V Uncore to get there. Then, I simply moved the processor's multiplier back to its default value and increased the voltage slightly above 1.3V.

Surprisingly, it proceeded to boot into Windows without any issues. However, it wasn't quite stable yet, but nothing some more voltage couldn't fix. Here are the final overclocked settings used in this review.

Core i5 750

Core i7 870

Power Consumption

Intel has definitely done its homework in order to keep power consumption down. Using out of the box settings, the quad-core Core i5 750 actually manages to draw less power than a similar system using a dual-core processor. Once the clock is forced to always remain at 2.66 GHz, the system draws an extra 30W under both idle and load conditions. It's pretty clear the power saving features are doing their job and when Turbo kicks in it should improve performance as well. Overclocking doesn't affect idle consumption, although it draws 46 more Watts under load.

The Core i7 870 tells a similar story, but this HyperThreading-enabled processor does require quite a bit more power than it's little brother. When it's idle with default settings it's saving 42W compared to when it's forced to always run at 2.93 GHz. The 9W difference under load isn't quite as drastic, but it's still better than nothing. Once overclocked, it draws 42 more Watts under load.

Sandra, by SiSoftware, is a tool capable of benchmarking about every component found inside a computer. The processor arithmetic and multi-core efficiency will be ran as well as the memory bandwidth and latency benchmarks.

Right from the start, the new Lynnfield processors make a great impression. In the processor arithmetic test, the Core i7 870 takes the lead above the i7 920, which just can't keep up due to it's clock speed disadvantage. The Core i5 750 sports the same clock speed as the i7 920, although it lacks HyperThreading support, which makes its scores dip below the mark set by the i7 920. However, it does keep a slight edge over AMD's latest Phenom's. The Q9650 just can't keep up with the rest of the quad-cores, while the E8400's performance simply seems mediocre.

Enabling Turbo mode gives the i7 870 a 8.5% performance boost, while the i5 750 gains a lesser, but not negligible, 5,1%. Not bad for an out of the box, dynamic and safe overclock.

The scenario changes a bit in the multi-core efficiency test where the i7 920's third memory channel gives it an edge over the 870. The Q9650's 3 GHz clock manages to rank above the i5 750. Turbo gives them very little performance in this case. However, overclocking takes both of them back in the lead. The dual-core E8400 is once again left behind, while the Phenom's strangely score very low in this benchmark.

When it comes to memory bandwidth, nothing comes near to the full fledged Core i7 920 and its triple channel memory configuration. That doesn't stop the i7 870 from scoring very well, only taking a 27% performance hit. The i5 750 doesn't do quite as well since its memory speed is locked to 1333 MHz, although overclocking can overcome this limitation. However, that's still enough to keep both Phenom's at bay, while the last generation Core 2's are way behind.

In the memory latency benchmark, both Core i7's end up with a comparable results, while the i5 750 is right in line with its direct competitor - AMD's Phenom. However, the i5 750 is only running memory at only 1333 MHz, while the Phenom's can and are set to run at 1600 MHz. Overclocking gives the i5 750 are fairly large improvement for that reason.

HandBrake is an open-source application used to transcode media files to other formats. It is multi-threaded so it exploits the power of modern quad-cores really well.

It's pretty obvious HandBrake really enjoys the HT-enabled processors, but it also craves for memory bandwidth. The i7 920 and its three memory channels takes the top stop above the the i7 870, which still shows great performance. The i5 750 alone isn't quite enough to beat the equally priced Phenom 955, but Turbo mode gives it enough extra power to pull ahead.

Enabling Turbo gives the i7 870 a modest 6% advantage, while it allows the i5 750 to cut its time by almost 7%.

POV-Ray, for Persistence of Vision Raytracer, is a 3D rendering software that has impressive photorealistic capabilities.

This benchmark also benefits from HT and especially high clocks, which takes the i7 870 above the i7 920. The i5 750's lower 2.66 GHz clock speed isn't enough to overtake either of the Phenom's. The previous generation Core 2's are, again, left at the bottom of the chart.

Intel's Turbo mode once again gives the new Lynnfield processors a welcome performance boost. The i7 870's nearly scores an extra 10%, while the i5 750 gains a more moderate 5%.

Everyone knows WinRAR, so no need to explain what it is. I will compress our custom 100MB, 500MB and 1000MB files using the best compression setting, in the ZIP format.

Results in this benchmark are fairly chaotic, which is one of the reasons why it's most likely the last time you'll be staring at it. Both of Intel's Lynnfield processors get beaten by AMD's Phenom's. However, Turbo Boost gives them a healthy performance increase.

Cinebench 10 is another rendering program, also optimized for many-core processors. I will run both the single-threaded benchmark as well as the multi-threaded.

In this benchmark, the i7 870 takes a comfortable lead over its cousin the i7 920. It also stays out of reach of AMD's Phenom's which pose no real threat to Intel's eight-thread processor in heavily multithreaded benchmarks. When Turbo is disabled, the i5 750 sits right under the similarly priced Phenom II 955, although it climbs right back up once you enable Turbo. Once more, the Core 2's occupy the bottom of the chart.

Turbo offers the i7 870 a 8% performance boost in Cinebench and the i5 750 nearly gains an extra 7%.

In case PCMark is a benchmarking suite from FutureMark, who also make the reknown 3DMark. It includes many tests to calculate overall system performance like hard drive speed, memory and processor power. It is a fairly good indicative of general real-world performance.

A quick look at the results shows that PCMark does not benefit from having more than four threads available. Thus, the i7 870 ends up ahead of both Phenom's, although the 965 isn't far behind. When it comes to the i5 750, the roles change. Intel's mainstream offering scores slightly under AMD's 955. However, Turbo easily overcomes this situation.

This benchmark really seems to enjoy the extra power provided by Intel's Turbo. In fact, it increases the i7 870's score by 13% and the i5 750's by an impressive 17%.

Demo's of those two gaming benchmarks can be downloaded for free. Call of Juarez is made by Ubisoft whereas World in Conflict is developed by Massive Entertainment. We run them at the lowest settings possible so the score isn't GPU-bound. It implies running a low resolution of 1024x768 for Call of Juarez and 800x600 for World in Conflict. This way, the processors' true power is exhibited.

Even at those low settings, it's hard to draw any clear conclusion's from Call of Juarez other than the fact that the game uses at most two cores. Every Intel processor scores within a margin of error, while the Phenom's are slightly behind, but only by a few frames.

This game also favors Intel processors. Even the i5 750 surpasses AMD's Phenom II 965. It's also interesting to note that the more expensive i7 920 platform doesn't perform any better than the Lynnfield processors in both of these games.

Lost Planet is a game developed by CAPCOM. It features a built-in benchmark which will be run at the lowest settings like the previous ones, including a resolution of 800x600. It has two different runs; one takes place in a cave whereas the other one is in a snow landscape.

In this game's benchmark, the processors perform just like their price tag suggests, except for the Core 2's which are, once again, sitting at the bottom. The higher clocked and more expensive i7 870 outperforms the full fledged i7 920 while the i5 750 very closely follows the Phenom 955.

Left 4 Dead is a first-person shooter developed by Valve. It uses the Source Engine. Four survivors must fight against infected people in order to reach a safe area.

Once we bring in a slightly more graphic intensive benchmark, the processors perform extremely similarly and whichever you choose hardly matters. However, the quad-core parts from both Intel and AMD are clearly ahead of Intel's own dual-core, showing quad-cores do prove useful in some games.

Crysis Warhead is a standalone expansion pack of the original Crysis. It uses an enhanced  and optimized version of the CryEngine.

Just like in Valve's Left 4 Dead, the processor doesn't really have an effect on performance in Crysis. Each and every processor delivers an excellent gaming experience up to 1650x1080, while the higher resolution is more or less playable depending on your standards.

Bioshock is a creepy first person shooter. It is the oldest of the games in our benchmarking suite, hence the high framerates.

This benchmark favors AMD's Phenom's, which manage to keep both Lynnfield's at bay. Other than that, the i7 870 somewhat justifies its price tag by once again pulling ahead of the i5 750 which also happens to pull ahead of both Core 2's.

Far Cry 2 is yet another first person shooter, but this one has been developed by Ubisoft. The story takes place in Africa, where the ultimate goal is to get rid of an arms dealer.

While both of Intel's Lynnfield's show off very similar results, they also are slightly slower than AMD's offerings and even the Core 2 Quad manages to keep ahead by a hair or two. This is also one of the few games where jumping from a dual to a quad-core does provide a notable difference.

While some think, or rather thought, of Lynnfield as Intel's Celeron version of Nehalem, in reality it's far more than that. Lynnfield did lose a couple features from the fully fledged Bloomfield core used in Core i7 920, 950 and 975. However, the Core i7 870 only gives up the third memory channel, while the Core i5 also loses HyperThreading support.

The Core i5 does have a another slight disadvantage. At stock speeds, it can only run memory at a maximum of 1333 MHz, 1600 MHz settings and up are locked just like early Core i7 920's were.

This is Intel's way of bringing their fastest architecture to the masses and, after seeing today's results, it's safe to say it was a good decision. It will not only successfully bring down some of the processor's prices, but also dramatically reduce overall platform cost. The Core 2 line of processors can now rest in peace, there is no reason to even consider such a system at this point.

The following chart shows the relative performance of the i5 750 compared to its direct competitors as well as Intel's own past generation quad-core and the popular E8400 to show how much of an improvement you will see from jumping to the latest mainstream platform.

In terms of performance, there is no doubt Lynnfield is a worthy replacement of Intel's Core 2 line of processors. It only lost three benchmarks and then the Core i5 750 took the remaining ones with a comfortable margin. The most interesting opponents here are AMD's Phenom's. Even though the 955 has a raw clock speed advantage of over 500 MHz, the i5 750 still is 6,6% faster on average. The 965 decreases that gap slightly more, although 3.4 GHz still isn't quite enough to call it a winner.

Let's take a closer look at the Core i7 870's performance now. AMD doesn't compete in that price segment, but I included the Phenom II 965's results for reference.

The Phenom II 965 and Core i5 750 are clearly no match for the expensive i7 870, which pulls ahead of them with ease. The i7 920 keeps the 870 on its toes even though it has a 233 MHz clock speed handicap, showing that the third memory channel does help in many benchmarks.

One of the much touted features of Lynnfield is the improved Turbo Boost. While Bloomfield processors also come with Turbo, they can only increase their multiplier by one notch. Lynnfield can take it up by up to five steps depending on the processor's load. I pulled results from our most processor intensive benchmarks and compared them with and without Turbo Boost enabled.

Needless to say that this feature is more than a simple gimmick. It gave between 5% and nearly 17% performance increase without requiring any sort of user intervention.

Before drawing any more conclusions, let's take a look at Intel's and AMD's pricing structure. Take note that Lynnfield pricing is based on 1000 units trays, so prices at your favorite retailer might and most likely will be higher until dust settles down.

Intel places their Core i5 750 right in line with AMD's Phenom II 955, which makes sense considering their performance. The Core i7 860 and 870 are priced similarly to Intel's own 920 and 950, respectively. However, looking strictly at the processor's pricing doesn't tell the whole story. Once you start adding the other primary components, Lynnfield suddenly looks more attractive to the mainstream market.

After picking a mid-range motherboard and memory to match each setup and adding up the numbers, it is clear that Lynnfield's platform price and performance are really interesting. A Core i5 750 based system will cost slightly less than a Phenom II 965, while simultaneously performing slightly better. Sitting between the i7 920 and 950, the Core i7 870 is, price-wise, in a totally different league, which doesn't reflect its performance. The sweet spot is undoubtedly the Core i7 860. At about $500, it hits a price point that should fit in many people's budget, while only being 133 MHz short of the i7 870.

Overall, both flavors of Lynnfield are great processors. At stock speeds, the i5 750 doesn't eclipse AMD's offerings as far as performance goes, but clock-for-clock Intel is far ahead. In fact, their 2.66 GHz processor manages to keep up and beat AMD's 3.4 GHz chip, albeit with Turbo which does provide a notable performance boost.

The i5 750 also draws very slightly less power at idle, but under load, it saves over 100W compared to the AMD's Phenom II's. Once you factor in overclocking, the gap only widens in favor of Intel. The best part? The price difference between them is negligible -- until AMD's next price cut at least.

I can already hear people asking if upgrading to Lynnfield from a Phenom II or Core 2 Quad system is worth it. Fortunately, the answer is fairly straightforward. If you can afford it and use a lot of processor intensive multi-threaded tasks, sure. However, if your main usage is gaming, especially at resolutions of 1650x1080 and above, investing in a better video card would be a better investment.

Finally, if you have been sitting on a dual-core system and holding out your upgrades, now is the perfect time to jump on the quad-core bandwagon without breaking the bank. They are faster, cheaper and less power hungry than ever.

While I wholeheartedly recommend the Core i5 750 to anyone looking to build a new computer, the Core i7 870 is a bit more of a mixed bag. There is no doubt that it's a fast chip. In fact, it's really fast, so if bleeding edge technology turns you on, then go for it. However, I find it hard to justify the price tag. The i7 860 seems like a much better option. At 2.8 GHz, it will only be slightly slower and priced about the same as the i7 920, but the savings add up once you add the other parts. I predict the i7 860 to be an excellent seller that gamers and overclockers alike will enjoy.

Speaking of overclocking, even though Intel's DP55KG motherboard gave me some trouble, they both overclocked extremely well. Better in fact than the i7 920's I have played with. As you will see soon enough, I had no issues reaching in excess of 4 GHz on another motherboard. On air cooling, Lynnfield overclocks at least as high as the Phenom's. Therefor, if you plan on leaving the stock clocks behind in favor of an healthy overclock, each and every Lynnfield will be faster than an equally clocked Phenom II.

Intel's manufacturing process has definitely improved since the chips now require less voltage to run at the same clocks. They also draw a lot less power and thus don't heat up as much, reducing the need of a beefy heatsink to keep temperatures under control. However, the heat scales up quickly once you start increasing voltages.

So the mainstream iteration of Nehalem has now hit the street -- and it should be a success story.  The benchmarking numbers speak for themselves, no matter how you look at them. As of right now, the Core i5 750 and i7 860 are superior options to AMD's latest quad-cores, while the Core i7 870 will cater to the wealthier enthusiasts who crave for the fastest thing around.


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