by Ilya Gavrichenkov
01/08/2007 | 05:21 PM
Released in the last summer, Intel's CPUs with the Core micro-architecture have won over the hearts of an overwhelming share of PC enthusiasts. Today, these CPUs provide the highest performance at relatively low heat dissipation and power consumption. Besides that, Core 2 Duo processors boast excellent overclockability that allows using them at frequencies far above their default ones. There is only one drawback about the Core 2 Duo. CPUs from this series are rather expensive, that's why they haven't yet conquered all the sectors of the CPU market. The junior model of the series cost as much as $183 (according to the official price-list), which cannot satisfy users who are limited in their PC budget.
But in the nearest future Intel is planning to extend the range of its dual-core CPUs with the Core micro-architecture downwards by releasing a few CPU models whose price should make them an appealing choice for low-end computers. The company is expected to issue its Core 2 Duo E4300 with an official price of $163 in January and to make this model even more affordable in the second quarter of this year by reducing its price to $113. Besides that, Intel wants to introduce a new series of inexpensive CPUs in the third quarter. It will be called Pentium E2000 and will include CPUs with the Core micro-architecture. The Pentium E2000 series is expected to lower the price of a Core 2 Duo processor to below $100.
There surely must be some prerequisites for such a dramatic change in the price policy. For example, AMD has mastered the manufacture of Brisbane cores on 65nm tech process and with 300mm wafers to be able to reduce the price on its own dual-core CPUs. Intel has been using such manufacturing technologies for long already, and the cheapening of the Core micro-architecture is not due to any technological breakthroughs, but is the result of minor changes in the CPU core design. The Core 2 Duo E4300 and some other models will be based on a new core codenamed Allendale in which the amount of L2 cache memory is reduced to 2MB. The Pentium E2000 processors will have even less of L2 cache memory - 1 megabyte only.
As a matter of fact, Intel has been offering Core 2 Duo processors with a 2MB L2 cache for some time already. These are Core 2 Duo E6300 and Core 2 Duo E6400, yet they are based on the full-featured Conroe core, with half the L2 cache disabled. The Allendale core will now obviously be used not only in Core 2 Duo E4000 processors, but also in the junior models of the E6000 series.
In this article we'll be discussing the new Core 2 Duo E4300 processor that we've been lucky to get into our hands. This CPU is most interesting today not only because it is based on the new Allendale core. It also differs from its senior mates in its support for an 800MHz FSB. This makes it a wanted product for an overclocker who will be able to overclock it without increasing the FSB frequency to an extremely high level.
After its release, the Core 2 Duo E4300 processor will be the junior carrier of the Core micro-architecture for a while. This is perhaps a more important fact than that it is based on the Allendale core. This new core is not interesting in itself as it differs but little from the full-featured Conroe. In terms of micro-architecture, the Allendale has half the Conroe's L2 cache, that's all the difference. This difference is not to be underestimated, though. Although the amount of L2 cache memory doesn't affect performance of Core 2 Duo CPUs much, Intel will save a lot on manufacturing the Allendale. The L2 cache accounts for about 60% of the Conroe core and the double reduction in the amount of transistors that make it up allows cutting the manufacturing cost of a CPU by about 20%. This must be the main reason behind the anticipated reduction of prices on junior CPUs with the Core micro-architecture.
Considering that, Allendale-core CPUs have predictable specifications. For example, the Core 2 Duo E4300 we will be discussing in this article has the following characteristics:
Core 2 Duo E4300
|Default clock rate|
|Enhanced Halt State (C1E) Technology|
|Enhanced Intel Speedstep|
|Execute Disable Bit|
|Intel Thermal Monitor 2|
|Intel Virtualization Technology|
The table shows that the processor's TDP hasn't changed despite the reduction of L2 cache in the Allendale core. However, the Core 2 Duo E4300 processor itself has remarkable features that put it apart from the E6000 series.
Take note of the bus frequency. Core 2 Duo E6000 series CPUs support a Quad Pumped Bus with a frequency of 1067MHz whereas the new Core Duo E4300 (and the Core 2 Duo E4400 that is expected to follow it soon) uses an 800MHz bus. It means the new processor's FSB frequency is 200MHz and it has a frequency multiplier of 9x. The new CPU will be more economical due to the lower bus frequency because it will be able to use EIST and C1E technologies to lower its clock rate not to 1.6GHz as Core 2 Duo E6000 series processors do, but to 1.2GHz.
Note also that the Core 2 Duo E4300 does not support Intel's virtualization technology.
The default clock rate of the new Core 2 Duo E4300 is 1.8GHz, which is only 67MHz lower than that of the Core 2 Duo E6300, the junior model with the Core micro-architecture up to this moment. But the new CPU will cost $163, which is $20 cheaper according to the official price-list, and is expected to hit the market as soon as January 21.
The new CPUs on the Allendale core will differ from Conroe-core CPUs visually: the elements on the CPU's bottom are placed in a different way.
Conroe-based Core 2 Duo E6300 (left) as opposed to Allendale-based Core 2 Duo E4300 (right)
In an assembled system, the informational utility CPU-Z reports the following about the Core 2 Duo E4300:
The default voltage of our sample of the CPU was 1.325V and CPU-Z got it wrong. Otherwise, the data in the screenshot are correct and expectable.
The Core 2 Duo E4300 is a real treat for an overclocker. Having a default FSB frequency of 200MHz and a rather high multiplier of 9x (the same as the Core 2 Duo E6600 has), this CPU should overclock much simpler than junior models of the E6000 series. You need to increase the FSB frequency to overclock the CPU and here it can hardly be limited by the capabilities of the chipset or mainboard as it was often the case with the Core 2 Duo E6300.
Well, the CPU's overclockability might be limited by other factors, too, as we found out in our tests. When we tried to use our Core 2 Duo E4300 on a DFI Infinity 975X/G mainboard, we found that we couldn't increase the FSB frequency above 300MHz whereas we could do that with Core 2 Duo processors from the E6000 series. It means that some optimizations in the BIOS code are necessary to overclock Core 2 Duo CPUs intended to work with a 200MHz FSB.
So, we examined the overclocking potential of the Core 2 Duo E4300 processor on an ASUS P5B Deluxe mainboard (see the full description of our testbed below). Using its latest version 0804 BIOS, this mainboard didn't have any problems with the new CPU. The CPU was cooled with a Zalman CMPS9500 LED cooler. We also set the memory frequency in sync with the FSB to avoid any troubles on the memory modules side. The overclocked system was checked for stability by running two copies of Prime95 simultaneously.
First we wanted to see what we could get without increasing the core voltage, which was 1.325V by default. Under such conditions, our Core 2 Duo E4300 could work at 2.97GHz - the FSB frequency had been increased to 330MHz.
This is a remarkable result. Without changing the core voltage, we reached a frequency which was higher than the default frequency of the Core 2 Extreme X6800, the fastest dual-core processor with the Core micro-architecture.
As we knew from our earlier tests, the Conroe core reacted well to a core voltage increase. So, we expected the same from the Allendale core, too. For our second experiment we increased the CPU voltage to 1.6V.
Our expectations were not misplaced: having increased the voltage by 20% above the default value, we achieved a 15% CPU frequency growth. In other words, we increased the FSB frequency to 380MHz and the resulting CPU frequency grew to 3.42GHz.
So, our sample of the Allendale-based Core 2 Duo E4300 processor didn't disappoint us with its overclockability. Following the standard procedure we increased the clock rate of our CPU in 1.9 times! We achieved this without employing any special cooling means - we used an air cooler.
However, this doesn't look that impressive if compared with what Conroe-based CPUs show at overclocking because Core 2 Duo E6000 CPUs can conquer somewhat higher frequencies. So, you can't expect to set any performance records by overclocking your Core 2 Duo 4300. This CPU is good for other reasons. It is cheaper than CPUs on the full-featured Conroe core and it is just simpler to overclock it since its default FSB clock rate is 200MHz rather than 266MHz.
We want to compare the Core 2 Duo E4300 with its closest market rivals. If you look up in today's price-lists, you will find that you can buy another Intel processor for the same sum of about $163. It is Pentium D 945. The Core 2 Duo E6300 model is a little more expensive. As for AMD's offers, this sum of money can buy you an Athlon 64 X2 4200+ which has become cheaper than its official recommended price. So, these four CPUs are going to perform before us today. Besides that, we will also benchmark our Core 2 Duo E4300 when overclocked to 3.42GHz by increasing the FSB frequency to 380MHz (the memory works in DDR2-760 mode in this case). We'll also include the results of the Core 2 Extreme X6800 into the diagrams to compare them with those of the overclocked Core 2 Duo E4300.
We used the following hardware for our tests:
We selected the highest-performance settings in the mainboards' BIOS Setup.
The first tests show that the Core 2 Duo E4300 on the Allendale core doesn't greatly differ in speed from the Core 2 Duo E6300. The 66MHz difference in clock rate coupled with the slower FSB leads to a small difference in performance, about 2-4%.
Note also the good results of the Pentium D 945 processor. Intel has cut prices on its CPUs with the NetBurst micro-architecture, so they are now a worthy alternative to Core 2 Duo and Athlon 64 X2, except in terms of power consumption. But let's be frank, the Pentium D 945 is still somewhat slower than the junior Core 2 Duo models.
Surprisingly, it's the Pentium D 954 that takes the lead in both tests from Futuremark. The Core 2 Duo E4300 is 1-3% slower than the Core 2 Duo E6300. That's just as we have expected.
The overclocked Core 2 Duo E4300 is impressive: clocked at 3.42GHz, it is 10-15% faster than the Core 2 Duo Extreme X6800 despite having half the amount of cache memory!
The Core micro-architecture shows its best in gaming applications. The junior Core 2 Duo models are far faster than the CPUs with the Intel NetBurst and AMD K8 micro-architectures here.
It is a special feature of gaming applications that they are sensitive to the bandwidth of the CPU-memory thoroughfare. That's why the Core 2 Duo E6300 has a bigger advantage over the Core Duo E4300 than in other benchmarks - the difference amounts to 6% in Quake 4 .
Besides the two games, we ran two benchmarks based on the Valve Source engine that is expected to be used in the upcoming Half-Life 3 . One benchmark shows the speed of processing the environment physics and the other measures the speed of creating lighting maps.
The Athlon 64 X2 4200+ is suddenly ahead of both CPUs with the Core micro-architecture in the environment physics test. Well, CPUs with the K8 micro-architecture are still very fast at modeling physical processes due to their high-performance FPU subunit.
These diagrams don't have anything new to tell us. The Core 2 Duo E4300 on the Allendale core is about 4-5% slower than the Core 2 Duo E6300 at encoding video and 2% slower at encoding audio.
The Allendale-based CPU shows good performance scalability depending on its frequency. When overclocked by 90%, the Core 2 Duo E4300 shows a performance growth of 75-90%.
There's no difference in image and video editing applications: like in the other benchmarks, the Core 2 Duo E4300 overclocked to 3.42GHz is considerably faster than the Core 2 Extreme X6800. This confirms our point that the amount of L2 cache memory doesn't influence performance of these CPUs much.
It's all expectable in the professional applications. There is a difference of 3-4% between the Core 2 Duo E6300 and the Core 2 Duo E4300 which roughly equals the difference in their default clock rates (it is 3.6%).
The Core 2 Duo E4300 processor has left a positive impression on us. It can become a bestseller thanks to its rather low price - after all, it is the cheapest CPU in the highly appealing Core 2 Duo series.
Performance of the Core 2 Duo E4300 isn't that impressive as that of the senior models of the series. Although it differs by only 3-5% from the Core 2 Duo E6300, rarely the new CPU is slower than the Pentium D 945 and Athlon 64 X2 4200+, which cost about the same money, in some benchmarks. But there are few such benchmarks and the new CPU is far more economical than any of its opponents.
The Core 2 Duo E4300 is also a gift for overclockers since it doesn't require special overclocker-friendly components and has an affordable price. But to all appearances, Allendale-based CPUs won't reach as high frequencies at overclocking as Conroe-based CPUs do.