Overclock3D.Net :: Print Page :: Intel Core i7-870 Lynnfield Processor

Introduction

Today is a big day indeed, not only for those with unhealthy fascinations for dates with identical or symmetrical strings of numbers but also for the masses. To be more precise, it’s an important time for those with more conservative budgets and those who consider value for money as their #1 priority when looking into upgrading, building or buying a computer. Socket T (LGA775), launched in 2004 has been through a lot over the years, featuring a vast number of processors, some of which are incredibly famous for all the right reasons and some for all the wrong reasons but from today, this popular platform will be steadily discontinued. Perhaps it seems a little odd to some that the socket is already being pushed aside as after all, even the best of the Core 2 Quad lineup continue to hold their own in the wide majority of mainstream applications but regardless, stagnation in a market such as this is never a good idea and on that bomb shell we bid LGA775 a farewell and a warm welcome to LGA1156 and it’s new range of Core i5 and i7 processors. Today, we will be testing the leader of the Lynnfield clan… Meet the Core i7 870 processor.

First and foremost, it should be acknowledged that this is not a LGA1366/Intel X58 compatible processor and as of today, the Core i7 exists on two different sockets. One way to spot the difference is to consider the model number, where i7 8xx’s are LGA1156 while i7 9xx’s are LGA1366. So what exactly differentiates the processors on LGA1156 with those on LGA1366?

The first two significant changes are that the Core i5/i7 range on the new socket only supports functionality of memory in Dual Channel mode and the i5’s do not feature Hyperthreading Technology. The new processors also sport integrated PCI-Express controllers, completely ousting the requirement for a separate Northbridge/Southbridge pairing but rather a single chip controller on the motherboard (dubbed P55) which handles the link between Motherboard/CPU as well as I/O devices by means of USB/SATA and so on. So what exactly is the point of this release? The end result is meant to be a platform that offers many of the perks of the exclusive X58 / Core i7 platform but with lower ownership costs thanks to cheaper motherboards and dual channel memory.

This may all seem quite confusing and I would forgive anyone who feels this way. Why Intel did not rename the LGA1156 i7 to i6 perhaps, in order to separate the two CPU's I cannot tell but it is certainly a confusing way of rebranding their lineup. Just when you thought Intel couldn’t baffle their prospective customers any further, Intel will also be releasing two energy efficient version of the i5 and i7 range with the i7-860s and i5-750s. These two processors will be clocked the same as their forbears but will have a lower TDP of 82W instead of the 95w of the earlier models. Expect these CPU's to be released around Q1 2010.

At the top of the pile will be the much anticipated flagship 'Gulftown' i9 processor. Rumors are suggesting that this processor will be compatible with Socket 1366 so everyone who has spent £250+ on an X58 motherboard can breath a huge sigh of relief because thankfully there is still life left in the X58 we all rushed out to buy. Even better is the news that Gulftown will be a 6 core monster with a total thread count of 12 processing two threads simultaneously. With an increase in L3 Cache to a stonking 12MB, the Gulftown will certainly a performance CPU to be reckoned with. Just as AMD seem to be bridging the gap, Intel release what appears to be yet another range of CPU's capable of moving the goal posts once more.

Looking further into the future, Intels 32nm lineup will come in six flavors, all of which will initially be dual core processors with an integrated DX 10 GPU, DDR3 memory controller and a TDP of 73W. The six CPU's will be spread across the Intel range with 2 models found in the i3 range, 3 in the i5 and the final version being part of the now aging Pentium family. Interesting times indeed.

Today, we will be concentrating on the Intel Core i7 - 870 which Intel have kindly supplied for this review.

Specifications

Name	Core i7-920	Core i7-870	Core i7-860	Core i7-860s	Core i5-750	Core i5-750s
Clock	2.66GHz	2.93GHz	2.8GHz	2.53GHz	2.66GHz	2.4GHz
Cache	8MB L3	8MB L3	8MB L3	8MB L3	8MB L3	8MB L3
Core	4	4	4	4	4	4
Threads	8	8	8	8	4	4
IMC	Yes	Yes	Yes	Yes	Yes	Yes
Memory Support	DDR3 1600/1333/1066	DDR3 1333/1066	DDR3 1333/1066	DDR3 1333/1066	DDR3 1333/1066	DDR3 1333/1066
Max Supported	24GB Triple Channel	16GB Dual Channel	16GB Dual Channel	16GB Dual Channel	16GB Dual Channel	16GB Dual Channel
Turbo Boost	3.2GHz	3.6GHz	3.46GHz	3.46GHz	3.2GHz	3.2GHz
Socket	LGA 1366	LGA 1156	LGA 1156	LGA 1156	LGA 1156	LGA 1156
Launch Date	Present	8-Sept-09	8-Sept-09	Q1 2010	8-Sept-09	Q1 2010

As you can see from the specification above, the i7-870 is higher clocked at stock than the i7-920 but forfeits the triple channel memory controller compared to it's bigger brother. On paper, the i5 simply appear to be lower clocked i7 (1156) CPU's so it remains to be seen if that is the case which will no doubt please overclockers who may well go for the cheaper i5 and increase the clockspeed manually to save a few bucks.

Alas, with a Core i5 test bed cleared for takeoff we can finally invite you to turn over the page to see what Intel’s range topping i7 870 has to offer!

Test Setup

To ensure that all reviews on Overclock3D are fair, consistent and unbiased, a standard set of hardware and software is used whenever possible during the comparative testing of two or more products. The configuration used in this review can be seen below:

Processor: Intel Core i7-870 (2.93GHz)
Motherboard: MSI P55-GD80
Memory: G-Skill Trident F3 DDR3-2000 CL9 4GB
Graphics Card: Asus GTX275
Power Supply: Gigabyte Odin 1200W
CPU Cooling: Coolermaster Hyper 212 Plus
Hard Disk: Hitachi Deskstar 7K160 7200rpm 160GB
Graphics Drivers: Geforce 180.60 CUDA
Operating System: Microsoft Windows Vista Ultimate x64 SP1

Thanks to the new Skt1156 design with the whole metal frame lifting away with the latch bar, installation of the CPU was even easier than before. The two notches are still there making fitment of the CPU a non-brainer however, care should still be taken not to bend those ever so fragile pins in the socket itself.

From the CPU-Z shot above you can see that the stock speed of the Core i7-870 is 2.93GHz when the bus speed is running at 133Mhz. As with most motherboards though, there are slight variations on this and the MSI board we are using for testing placed the bus speed slightly above spec at 133.7MHz resulting in a clockspeed of 2.94 but for intents and purposes this should be 2.93. As with the Core i7-920, the i7-870 has the Intel Turbo feature allowing an instant overclock by increasing the multiplier by two on the primary core and 1x on the remaining three so the cores are clocked to 24, 23, 23, 23 when you need the extra power most giving an overclock of 3.6GHz. This is in stark contrast to the stock clockspeed of the i7-920 being 2.66GHz with a Turbo boost of 3.2GHz - nice!

Overclocking

Anyone who is familiar with overclocking the older Skt1366 i7 will feel pretty much at home with the new revision i7 in that the base clock is still there acting for all intents and purposes like the FSB of old.

I initially tried overclocking the Core i7-870 with the Turbo technology enabled which resulted in a maximum clock of 4429MHz. However, I was not satisfied that 185 on the base clock was the maximum available and so did a little manual tweaking and managed to hit 205.5 Bclk resulting in a whopping 4521MHz! This was far from stable though but I do feel were I to be a little braver with the voltages then this could indeed be stablised. 1.4v was the maximum Vcore I used on the chip, as with the older Core i7-920 but the newer i7 surpassed the older chip by a fair margin.

Lowering the overclock I attempted to gain some stability I run a few runs of 3D06 and SuperPI 1M. While SuperPI is by no means the definitive test of stability, it does give an indication of what the CPU is capable of, much more so than a CPU-Z suicide screenshot. 4.45GHz was the maximum I could achieve with this setup on air cooling with a Vcore limitation of 1.4v. An amazing result, especially when you consider that the temperatures were also lower than that of the Core-i7 920 being around 35c idle and 68c load compare to 47c idle and over 85c for the 920. Obviously a pinch of salt has to be added to these temps as totally different setups were used but I would be happy to stake my reputation on the fact that the Core i7 8xx series run cooler than the 9xxx series counterparts.

Returning the CPU to it's stock settings (Turbo, EIST and C1E disabled) I ran a few benchmarks to see how the CPUs performance compares to other popular systems on the market at present...

SiSoftware Sandra (the System ANalyser, Diagnostic and Reporting Assistant) is an information & diagnostic utility capable of benchmarking the performance of individual components inside a PC. Each of the benchmarks below were run a total of five times with the highest and lowest scores being discarded and an average being calculated from the remaining three.

SuperPI is the benchmark of choice for many overclockers. It's lightweight to download and can give a quick indication on how good a system is at number crunching. Once again, testing was performed a total of 5 times, with an average being calculated from the middle three results.

PassMark is a popular benchmarking suite which test all aspect of PC hardware.The CPU test examines Mathematical operations, compression, encryption, SSE, 3DNow! instructions and more. Each CPU test was performed a total of 5 times, with an average being calculated from the middle three results.

Results Analysis

In the above tests, the i7-870 was clearly the highest performing CPU thanks in part to the 2.93GHz clockspeed. These results would no doubt increase significantly were I to apply the massive overclock this CPU is capable of. One should however bear in mind that the i7-870 is the range topper in it's class as opposed to the i7-920 which sits itself on the bottom rung of the ladder. That said the flagship AMD Core lagged way behind the competition in this run of benchmarks which shows, for now at least, Intel still hold all the aces.

Let's see how the dual channel memory controller performs...

Everest is in many ways similar to Sisoft Sandra. Focusing mainly on software and hardware information reporting, Everest also comes with a benchmark utility suitable for testing the read, write and latency performance of the memory subsystem. Each of these benchmarks were performed a total of 5 times with the highest and lowest scores being discarded and an average calculated from the remaining three.

Results Analysis

As expected, the dual channel memory controller of the i7-870 simply pales in comparison to the might of the triple channel controller of the i7-920. How much you desire memory performance will depends greatly on your choice of application but as we have shown in previous reviews, the sweet spot appears to be 6GB for most tasks with only large image processing require the huge amounts of bandwidth the i7-9xx series afford. We will shortly be reviewing an 8GB kit for the P55 chipset soon so it will be interesting to see exactly how this compares.

Let's move on to the Mutlimedia and encoding performance...

7-Zip is an open source Winzip-style file compression utility that has the ability to compress and decompress many file formats including its own .7z compression scheme. 7-Zip also comes complete with its own benchmarking utility for gauging the compression and decompression speed of the system that it is installed on.

Results Observations

Again, we see that the raw grunt of the i7-870 appears to take the spoils in Sisoft Sandras assessment of the CPUs capabilities. Strangely though, the little i5-750 came out on top when the CPUs were being used for compression and decompression benchmarking. This area is one of AMD's strong points and thus put in a very good performance, almost matching Intels finest.

Let's move on to our 3D Benchmarks...

Cinebench 10 is a benchmarking tool based on the powerful 3D software Cinema 4D. The suite uses complex renders to gauge the performance of the entire PC system in both single-core and multi-core modes. Testing was performed a total of 5 times with the highest and lowest results being omitted and an average created from the remaining 3 results.

3DMark is a popular synthetic gaming benchmark used by many gamers and overclockers to gauge the performance of their PC's. All 3DMark runs were performed a total of 5 times with the highest and lowest results being removed and an average calculated from the remaining 3 results. Also included are the CrossfireX results to give an indication of how 8x PCIe lanes perform.

Results Analysis

Surprisingly, the i7-870 could not gain a clear advantage over the i7-920 despite its higher clockspeed. The advantage of those extra MHz however were clearly apparent in the two 3DMark benchmarks where the i7-870 took the other three CPUs on test by the scruff of the neck and gave them a good slapping.

In our final benchmark we take a look at the effect the i7-870 will have on overall system performance with Futuremarks PCMark Vantage. Let's see how it got on...

Conclusion

With AMD rapidly gaining ground on Intel, the pressure was on for them to keep the gap instilled by the Core2 series. The phenomenal success of the Core range has seen Intel race away from it's major competitor and despite AMD clawing some ground back recently, Intel have once again come up trumps with a revised CPU that will keep the hounds from the door and add yet another nail to the green coffin of AMD.

The revised Core i7 is even faster than before with a clockspeed of 2.93GHz with a stable overclock of 4.45GHz some 1.5GHz faster than stock which will no doubt please enthusaists and quash the rumours that the new chips are locked down with restricted overclocks. I would liked to have seen triple channel support as with the Core i7-9xx range as I feel the dual channel may prevent a lot of enthusiasts upgrading to the new i7 8 series, favouring instead the cheaper i5 range. Intel are keen to point out that the new i7 CPU still offers plenty of bandwidth for the end user but I still believe that utilising a dual controller is a step backwards.

However, the reasoning behinds Intels apparent madness is actually quite logical. By removing that extra memory controller and taking the QPI link and replacing it with the slower DMI, Intel are aiming more for the masses rather than the Ultra high end sector of the market. Because of the reduction in specification, Intel can lower the fabrication cost which can then be passed on to the consumer. Couple this with the cheaper P55 chipset required for the new skt 1156 CPU's and you have the makings for a much cheaper setup than the X58/Core i7 9xx combination. What I still fail to understand is why name the CPU the same as it's skt1366 sister CPU. Sure the 7, 8 and 9 series do distinguish the CPU's a little but I would still have preffered Core i6 or similar. I can see many DSRs being abused due to this renaming strategy which will be a continual headache for e-tailors.

The CPU we had for review today was the range topping Core i7-870 which, like all flagship products carries a high pricetag. While we are yet to receive official prices from Intel, I estimate the i7-870 will be around the $550 mark equating to a guestimate of around £330 when tax, import and UK rip-off prices are taken into account. That's not such a bad price when you consider that the entry level i7-920 upon initial release was close to that mark. The more mainstream 860 and Core i5-750 will be around the $275 and $190 respectively which will be much more affordable and no doubt more popular that the i7-870 we have reviewed today albeit a tad slower in operation in stock format.

It's hard not to admire Intels R&D department as just when you think things cannot get any faster, they go and prove us all wrong. While the i7-8xx range is hardly as groundbreaking as the original Core series, nobody can dispute that Intel have waved their magic wand over the Core series refresh and by trimming the expensive fat from the obese 9xx series they have packaged a product more affordable for the masses.

The Good

- Performance

- Overclocking

- Retention of 8mb L3 Cache

- Turbo Technology

- Price

The Medicre

- Temperatures, while less than 9 series are still quite high

- Memory bandwidth suffers thanks to the lack of a triple channel controller.

The Bad

- Confusing name

Thanks to Intel for supplying us with the Core i7-870 CPU for todays review. Discuss in our forums.