Core i7 Extreme processors aren’t very popular judging by their sale volumes but their market positioning is pinpoint accurate. They are targeted at desktop users who want to have the best possible PC configuration. The Core i7 Extreme is the most desired option for enthusiasts who are into liquid-cooling solutions and multi-GPU subsystems. Yes, it is very expensive, yet it does let you build a maximum-performance and feature-rich platform. That’s why the Core i7 Extreme series keeps on developing.
Moreover, it looks like top-performance premium-class desktop PCs are not affected by the declining demand trend which dominates the PC market in general. Such computers still sell well, making Intel change its attitude towards them. The company’s top managers have promised to bring enthusiast-level CPUs back into their list of priorities.
The first step in this direction was made this summer with the release of the Devil’s Canyon series for high-performance overclockable computers. Based on the modern Haswell design, they come with clock rates above 4 GHz, which ensures a substantial performance boost. However, they cannot be regarded as the perfect option for uncompromising enthusiasts who own LGA2011 computers with six-core CPUs, quad-channel memory subsystems, lots of PCI Express lanes, etc. You don’t get any of that with the Devil’s Canyon series but, fortunately for enthusiasts, Intel has got a special solution for them.
We mean the Haswell-E CPU series, the LGA2011-v3 platform and the X99 chipset. Together, they provide everything a hardcore computer enthusiast might ever wish: multi-core CPUs with lots of cache memory, high-speed DDR4 SDRAM, and mainboards with an exhaustive selection of interfaces. Moreover, the Haswell-E is the only up-to-date CPU which has indium-based solder between the cap and the die. Being much more efficient than conventional thermal interfaces, it provides great overclocking benefits.
The new platform was officially announced on August 29, but we’ve waited a little for all of its components to become widely available. So today we can check out all existing LGA2011-v3 processors: Core i7-5960X Extreme Edition, Core i7-5930K and Core i7-5820K.
Compared to the previous generation, Ivy Bridge-E, the new products of the Haswell-E series bring improvements in nearly each and every field with, perhaps, but one exception. They are manufactured on the same 22nm tech process with 3D transistors as their predecessors. Intel has already begun mass shipments of 14nm chips for tablets and slim notebooks, but the Haswell-E series is unified with server products which are not prone to be the first to feature new manufacturing technologies.
The key innovation is highlighted in the new series’ name: it is based on the Haswell design. Compared to the Ivy Bridge design, it is 5 to 10% faster (at the same clock rate) and supports the AVX2 instruction set for parallel data processing. With a voltage regulator built right into the CPU die, the Haswell design also allows for more accurate and energy-efficient power management.
Since the new Haswell-E processors are targeted at a rather small group of computer enthusiasts, we don’t have lots of models in the series. Like the earlier Sandy Bridge-E and Ivy Bridge-E series, it is comprised of only three models.
There are, however, differences in what these three models are. The flagship Core i7-5960X is a true 8-core processor with a 20MB L3 cache. Intel has never produced such desktop products before. Supporting Hyper-Threading, the processor can execute up to 16 threads concurrently. Its base clock rate is set at 3.0 GHz and its integrated PCI Express 3.0 controller provides 40 PCIe lanes. Like earlier Extreme Edition models, it is priced at $1000, but its clock rate doesn’t seem to be high. Well, the two additional cores increase its heat dissipation, so the clock rate has to be reduced in order to meet the TDP requirements. The Turbo Boost feature makes up for that somewhat as it can increase the clock rate of the Core i7-5960X by up to 3.5 GHz at low and medium loads.
The Core i7-5960X is head above the previous flagship Core i7-4960X, the latter being comparable to the new midrange model Core i7-5930K. Like the i7-4960X, the i7-5930K has six x86 cores and a 15MB L3 cache, and supports 40 PCIe lanes. The new model has a lower clock rate, but the Haswell microarchitecture and the quad-channel DDR4 SDRAM controller should make up for that difference. The midrange Haswell-E costs about $600.
It is the junior model, Core i7-5820K, which seems to be the most interesting in the new series. With six cores, a 15MB L3 cache and a quad-channel DDR4 SDRAM controller, it only has 28 PCIe 3.0 lanes. This doesn’t seem right because it is only with LGA1150 platforms that we used to have a PCIe controller incapable of supporting two full-speed PCIe x16 slots. But we can put up with that deficiency because the rest of the specs are very good. The junior models of the Ivy Bridge-E and Sandy Bridge-E series, Core i7-4820K and Core i7-3820, were quad-core processors, but now we are offered a 6-core one for the same money ($400). The lack of support for x16/x16 graphics configurations is no big deal, especially as SLI and CrossFireX setups are not really limited by the interface bandwidth even when using PCIe x16 slots at x8/x8 speed. We know that by LGA1150 platforms. And unlike LGA1150 processors, the Core i7-5820K allows building a 3-component graphics subsystem with a speed formula of x8/x8/x8. The only significant difference of the junior model from its senior cousins is that it doesn’t support SLI configurations with four graphics cards but that hardly concerns many users.
The semiconductor die employed in the Haswell-E series is similar to the Sandy Bridge-E and Ivy Bridge-E in its layout. There’s a 20MB L3 cache in the center. It is surrounded by eight x86 cores, a DDR4 SDRAM controller and an Uncore unit, all combined into a single whole by a ring bus.
This 8-core die is used in all Haswell-E models but two x86 cores are disabled in the i7-5930K and i7-5820K. In fact, the 6-core models are made out of defective 8-core chips because any two opposite cores may be turned off. The section of the cache memory in between is disabled as well. That’s why the Core i7-5930K and Core i7-5820K have a smaller L3 cache than the Core i7-5960X.
A full Haswell-E die is 356 sq. mm large, incorporating 2.6 billion transistors. You can compare this with regular quad-core Haswell-based processors which have a 177 sq.mm die consisting of 1.4 billion transistors. The Haswell-E doesn’t set a new size record for desktop CPUs, though. It is larger than AMD’s 8-core Vishera, yet the 6-core Sandy Bridge-E have an even larger die (435 sq. mm). Compared to the previous flagship Ivy Bridge-E processor, the Haswell-E is larger by 39% and has 40% transistors more, their manufacturing process being the same (22 nm). The increase in transistor budget accounts for the 33% increase in x86 cores and the more sophisticated memory controller which now supports DDR4 SDRAM.
The newer CPU design and the integrated voltage regulator make the Haswell-E consume more power than their Ivy Bridge-E predecessors: 140 vs. 130 watts. That’s not a serious difference, though. Nearly all older coolers for LGA2011 CPUs are compatible with Haswell-E models. Moreover, Intel recommends the same cooler for them (a closed-circuit liquid cooling system TS13X with a 120x120x25mm radiator).
Take note, however, that the heat dissipation of the Haswell-E increases rapidly as soon as you overclock it – up to 200 watts in our tests!