Bloomfield and Lynnfield are followed by Clarkdale: Review of the new Intel CPUs with Core i3 and Core i5. PC Games Hardware tests what the entry-level processors are capable of.
Clarkdale CPU review [Source: view picture gallery]
The Core series is complete: On January 7, 2010 Intel introduces a new CPU generation for the lower and middle price region - the Clarkdale also known as Core i3/Core i5. The new processors will succeed the more than three years old Core 2 series. Intel Clarkdale in detail
Intel's name for the latest processor architecture with 32 nanometer technology is Westmere. The new CPUs will at first be added to the existing Nehalem product array and replace the old structure later. All in all three chip families have been based on the new architecture: Gulftown (high-end desktop/server), Clarkdale (middle-class desktop) and Arrandale (notebooks). While it will take some more months until Gulftown is released, the market introduction of Clarkdale and Arrandale is taking place in January. Clarkdale will be marketed as Core i3 and Core i5-600 and is intended for the section slightly below the current Lynnfield products. Arrandale is coming as (mobile) Core i3, i5 and i7 with an "M” tag.
The new Core i5 models with Clarkdale core, from the small Core i3-530 to the i5-670 will probably be the most interesting processors for gamers. They all fit into the socket LGA 1156 and are going to be released with frequencies ranging from 2.93 to 3.46 GHz, the Turbo Mode can increase it up to 3.73 GHz. Important note: Only processors of the Core i5 series have the Turbo Mode feature while the Core i3 Clarkdales don't have the automatic overclocking ability. The identification number of the i5 Clarkdales always starts with a "6” - thus the processors are placed a little below the current Core i5 with Lynnfield core (Core i5-750 etc.) The retail market is provided with for models (i5-650, 660, 661 and 670) with more variants expected to be released later this year. The Core i3 series has a "5” in the identification number and Intel offers two models (Core i3-530 and 540).
Intel Clarkdale: Technical details
Clarkdale Die [Source: view picture gallery]
All desktop models have two cores and support Hyper-Threading - thus they can work on four threads simultaneously. The Core i5 Lynnfield in comparison has two more physical cores but misses two logical cores - or to put it another way: Clarkdale exchanges two real cores with two simulated cores, which actually is the chip's biggest problem (more on that later). Each Clarkdale and Arrandale processor has four MiByte L3 cache, half as much as the Lynnfield models. Like them the Clarkdale and Arrandale models support two memory channels at max (DDR3-1333) - three channels are supported by Bloomfield CPUs only. But the real innovation of Clarkdale and Arrandale is the integrated graphics chip which is faster than Intel's previous motherboard graphics chips and has low power consumption at the same time.
Clarkdale processors also come with several new instructions which are primarily intended to accelerate encryption (AES, Advanced Encryption Standard). The six commands can for example be used to encrypt single files or whole hard drives faster than before. Furthermore it is now possible to make the encryption of internet phone calls (Voice over IP) more efficient. Intel Clarkdale reviewed: CPU test
Since most gamers have a dedicated graphics card we ran most tests without the on-chip graphics unit. Thus the new dual-core Westmere with 4 MiByte L3 cache (with Hyper-Threading) competes with the quad-core Lynnfield with eight MiByte L3 cache (without Hyper-Threading), its predecessors from the Core 2 series as well as the products from AMD. The Clarkdale tests were run with Windows 7 because this operating system is able to work correctly with Hyper-threading cores - please note that the comparative results were made on Windows Vista SP2.
Since most of the current games are optimized for multi-core systems the Clarkdale processors are beat by CPUs with four cores although they run at noticeably higher frequencies. Even on windows 7 Hyper-Threading can't deliver a noticeable advantage in games and furthermore the L3 cache has been halved. Thus in most games the i5-660 running at 3.33 GHz is beat by an i5-750 (Lynnfield) which is running at only 2.66 GHz - the gap between the processors is quite small though. The Clarkdale also looses against AMD's top CPUs X4 965 and X4 975. Only if overclocked to 3.8 to 4.0 GHz the new Core i5 processor reaches the level of a Core i5-750 or even the performance of a Core i7-920 in Far Cry 2.
The results of the application tests confirm the performance development: In Paint.Net even the fastest Clarkdale is slower than an older Core 2 Quad Q6600. In Cinebench the Core i5-661 is about as fast as a Phenom X4 9950.
On the positive side the first Westmere processors have low power consumption, combined with low temperatures. If the graphics core is used, the TDP reaches only 87 watt. In case of the i5-660 this is only 22 watt higher than the E8600 which is running at the same frequency but doesn't include the energy needs by the graphics card or an onboard graphics unit. The CPU temperature is, given the high core frequency, very low. The same applies to the power consumption. Under workload the i5-661 - without its graphics unit - needed almost 40 watt less than the i5-750 although it has of course two physical cores only.
Westmere: new efficiency features [Source: view picture gallery]