AMD company has long abandoned attempts to compete with Intel processors in the upper price segment and is not going to return to this market at least until at its disposal there are fundamentally new chips built on the promising micro architecture Zen. However, this does not mean that enthusiasts do not have to deal with the choice problem when building modern high-performance systems. The fact is that different approaches to building such configurations allow only one assortment of Intel processors because for this purpose one can choose one of two different platforms: LGA1151 and LGA2011-v3. And let Intel believe that these platforms are fundamentally different weight categories, in fact, to assemble a high-performance PC that fully meets the needs of modern mass applications and games, you can choose any option. Moreover, with a weighted approach, the differences in the cost of such assemblies may well not be glaring at all.
Yes, the flagship processors for the LGA2011-v3 platform, such as the Core i7-6950X Extreme Edition or the Core i7-6900K, differ in the space price that goes beyond the 1,000-dollar mark. However, for large-scale high-performance systems, they are not really needed. The proposed arsenal of eight or ten computing cores is a very specific asset, which is really necessary only when solving certain resource-intensive tasks related to the creation or professional processing of digital content. If your goal is to build a computer primarily for consumption, and not for the production of content, then the optimal choice is four or six-core processors. And just in this case, the platforms LGA1151 and LGA2011-v3 can be treated on a par with each other.
Indeed, the current six-core processors in LGA2011-v3-performance, especially if we talk about the younger representative of this model range, differ in price from the older LGA1151-quad core is not too serious. At present, the cost of such models for different platforms differs by no more than $ 100, that is, in relative terms, it diverges by about a quarter. And it is this fact that can sow doubts as to which of the chips is more preferable for a modern system: either – the senior quad-core LGA1151 processor Core i7-6700K with frequencies in the region of 4,0-4,2 GHz, or – the younger LGA2011-v3- a six-core Core i7-6800K with a nominal frequency of 3.4-3.6 GHz, and maybe even a more expensive and high-speed six-core Core i7-6850K.
I must say that some time ago we already conducted a similar study, in which the “foreheads” of the older quad-core and low-end six-core processors present on the market were presented. And the results turned out to be far from obvious: even in the face of the four-channel DDR4 memory and the more advanced PCI Express controller, which was available on the LGA2011-v3 platform, under real load more simple quad-core often won. However, since then the situation has changed dramatically. Actual at that time processors in LGA1150- and LGA2011-v3-performance were based on the same Haswell microarchitecture. Today, the new LGA2011-v3-six-core family Broadwell-E and quad-core Skylake processors for the new LGA1151 platform should be compared. In other words, we need to talk about comparing the CPUs, which differ not only in frequency, cache size and a number of cores, but also have different micro architecture. In addition, their price positioning has also changed somewhat. If earlier the gap in the cost of junior six-core and older quad-core did not exceed $ 50, today it has become twice as large.
All this served as a sufficient argument in favor of new testing, in which the older Skylake and younger Broadwell-E were matched. The interest in carrying out such a comparison also arose with the company Regard, willingly took the burden to provide our laboratory with Broadwell-E processors, with which the Russian Intel subsidiary, unfortunately, could not help us. And in the end, we collected in one test several actual heterogeneous processors with prices ranging from $ 300 to $ 600: Core i7-6850K, Core i7-6800K, and Core i7-6700K, as well as a group of the same LGA2011-v3 processors of the past generation. A performance study conducted with this set of participants will give an answer to the pressing question: which processor should high-performance enthusiasts choose for assemblies that are oriented toward solving common mass tasks?
⇡ # Core i7-6850K and Core i7-6800K in details
Intel updated the processors in LGA2011-v3-performance at the very end of May. In its framework, the current line of high-performance multi-core CPUs, previously based on the Haswell-E design, has acquired a newer Broadwell-E architecture, which shares common roots with the Broadwell-EP server processors that were released earlier. As a result, the Core i7 family is replenished with four new representatives with model numbers from i7-6800K to i7-6950X.
|Core i7-6950X||Core i7-6900K||Core i7-6850K||Core i7-6800K|
|Core / Threads||10/20||8/16||6/12||6/12|
|The clock frequency||3.0 GHz||3,2 GHz||3.6 GHz||3,4 GHz|
|Max. frequency in turbo mode||4.0 GHz||4.0 GHz||4.0 GHz||3.8 GHz|
|Support for the Turbo Boost Max 3.0||There are||There are||There are||There are|
|Unlocked multipliers||There are||There are||There are||There are|
|L3-cache||25 MB||20 MB||15 MB||15 MB|
|The number of lines of PCI Express 3.0||40||40||40||28|
|TDP||140 W||140 W||140 W||140 W|
|The processor socket||LGA2011-v3||LGA2011-v3||LGA2011-v3||LGA2011-v3|
|The price is||$ 1,723||$ 1,089||$ 617||$ 434|
The processors Core i7-6950X and Core i7-6900K with ten and eight processing cores, respectively, we discussed earlier, today we’ll talk in detail about the remaining pair of models, which has six cores, Core i7-6850K and Core i7-6800K.
Despite the fact that the new LGA2011-v3-six-cores on the background of their older counterparts seem not to be such advanced chips, they are based on the same 14-nm semiconductor crystal LCC, which initially provides ten cores. But in the production of Core i7-6850K and Core i7-6800K, four out of ten cores are deactivated by hardware. At the same time, access to the cache blocks related to the disconnected cores is lost, as a result of which the six-core processors receive a L3-cache with the volume of only 15 MB.
Intel’s reluctance to develop for the Core i7-6850K and Core i7-6800K its own semiconductor crystal is understandable. First, these processors are expensive so much that their retail price fully covers the production cost of a large 14-nm crystal with an area of 246 mm 2 . Secondly, the volume of their sales is not too high, yet the desktop platform LGA2011-v3 is a niche offer. Thirdly, thanks to Core i7-6850K and Core i7-6800K, Intel gets the opportunity to sell partially defective crystals, which can not be used in eight-core and 10-core Core i7 and Xeon. In other words, the existence of the Core i7-6850K and Core i7-6800K in this form for Intel is profitable.
As for enthusiasts, it’s also a sin to complain about them. After all, if there were no offers in the model line such as Core i7-6850K and Core i7-6800K, they would have to pay several times more for the entrance ticket to the LGA2011-v3 ecosystem. In addition, the reduced number of cores gives certain advantages, for example, the ability to work at higher clock speeds within the same thermal package. It’s easy to see that, while the nominal clock speed of the tenth core Core i7-6950X is only 3.2 GHz, the older six-core processor on the same processor design received a 3.6 GHz pass rate.
It should be noted that the two six-core Core i7-6850K and Core i7-6800K models have much more serious differences than just slightly different frequencies. Expensive version, Core i7-6850K is a full-fledged model, trimmed in relation to older Broadwell-E only in terms of the number of computing cores and the volume of L3-cache. Core i7-6800K costs almost $ 200 less, and at 200 MHz the lower clock speed is just one of the reasons for such price differentiation. In addition, this processor is equipped with a simplified controller PCI Express bus, which has only 28, not 40 lines. In theory, this limits the performance of multi-GPU configurations, allowing them to be configured only by PCI Express 16x + 8x. However, this can be really sensitive only if AMD cards are combined, which exchange data exclusively on the PCI Express bus and do not use any connecting bridges.
That is, taking into account modern realities – the low popularity of CrossfireX-configurations, the limitation of support for SLI in new NVIDIA graphics cards with only two GPUs, the use of new bridges with increased bandwidth, as well as small real differences in the performance of video cards with eight connections and sixteen lines of PCI Express 3.0, then we can safely say that the loss in the Core i7-6800K 12 lines of PCI Express is not so terrible. The remaining capacity of the PCI Express controller should be sufficient for two high-performance GPUs, NVMe-drives and even for additional network cards.
In the rest, the Core i7-6800K differs little from the Core i7-6850K. Both of these processors have a full set of overclocking functions, including new possibilities for independent control of the multipliers of individual cores and a decrease in the frequency when executing AVX instructions. The four-channel memory controller of these processors compared to the Haswell-E memory controller is improved: it supports higher DDR4 SDRAM frequencies without the need to increase the BCLK frequency and is also compatible with 16 GB memory modules. Plus, both of these processors implemented a new, single-core turbo Intel Turbo Boost Max 3.0. True, to storm the standard frequency of 4.0 GHz it allows only the older processor Core i7-6850K, and in the younger model Core, i7-6800K auto-dispersal is allowed only up to 3.8 GHz.
With the operating modes of the six-core system, the situation is the same. The nominal clock speed of Core i7-6850K is set at 3.6 GHz. In reality, under the multithreaded load, we often see the operating frequency at 3.7 GHz.
It should be noted that our Core i7-6850K had a rather high supply voltage – 1,174 V. This is significantly higher than the voltage we saw in its more multi-core counterparts. And moreover – with a low-current load, when the frequency of the Core i7-6850K can rise to 4.0 GHz due to the work of Turbo Boost technologies of the second and third versions, the power voltage rises even more – to the value of 1,283 V.
For the younger model Core i7-6800K, the passport frequency is 3.4 GHz. However, in practice, even with a multithreaded load, this processor operates at a frequency of 3.5 GHz. The supply voltage in this state for our specimen was 1.146 V.
When the intensity of the load drops to a single-flow mode, the frequency increases to 3.8 GHz with a simultaneous increase in the supply voltage to 1.25 V.
The frequency of the built-in north bridge of both six-core Broadwell-E generations is 2.8 GHz, which is slightly lower than the frequency of the north bridge in Haswell-E. This is the reason for a slight increase in the latency of the third-level cache memory for new generation processors. As an illustration of this fact, we can cite the results of the AIDA64 Cachemem benchmark, performed on Broadwell-E and Haswell-E processors running at the same frequency of 4.0 GHz.
As you can see, the differences in the speed of L3-cache work are not limited to. Broadwell-E has a bit higher memory latency. However, in part, this is compensated by the increased recording speed in memory.
Judging by the characteristics, the new six-core Core i7-6850K and Core i7-6800K families of the Broadwell-E family are replacing the Core i7-5930K and Core i7-5820K processors. They offer almost the same basic characteristics and have a similar cost. However, the new processors are manufactured by a more advanced technological process with a resolution of 14-nm, which gives them slightly higher frequencies achievable within the same 140-watt thermal package. As a result, the six-core representatives of the Broadwell-E family bypass similar Haswell-E by about 100 MHz, plus the added single-core turbo Intel Turbo Boost Max 3.0. The advantage is not particularly noticeable, but we should not forget about the small increase in specific performance provided by the Broadwell microarchitecture.
All this in total gave Intel sufficient grounds to install higher prices on Core i7-6850K and Core i7-6800K compared to similar Haswell-E processors. The recommended price of the Core i7-6850K is $ 617, which is $ 34 more expensive than the Core i7-5930K, and the Core i7-6800K is estimated at $ 434, which exceeds the official price of the Core i7-5820K by $ 45.