Contemporary AMD Platform in Mini-ITX Format

Asus designed M4A88T-I Deluxe Mini-ITX mainboard for Socket AM3. With this mainboard and energy-efficient Athlon II processors we put together a unique system: compact, fast and energy-efficient and built using only AMD components.

by Ilya Gavrichenkov
12/20/2010 | 01:48 PM

The launch of Intel Atom processors boosted significantly the popularity of nettop computers. A lot of users were ready to switch to these compact and quiet systems that were designed to fit seamlessly into the living-room environment and didn’t take up much space. Of course, Intel Atom based systems cannot boast outstanding performance, but in many cases performance is not the No. 1 priority, especially if the computer is not used for 3D gaming or multimedia content processing and mostly serves as a “window into the Web” and an intelligent typewriter. In other words, Atom’s success in desktop systems proved that many users are ready to sacrifice high performance for the sake of “home-friendly” exterior.

 

However, dedicated computer enthusiasts do not take Atom seriously, of course.  The performance of this processor is comparable with that of Celeron D from 2006-2007. But miniature nettop systems really get them thinking about making their powerful systems smaller in size. Certainly, if you replace the traditional massive steel casket on top of your desk or under it with a small and neat box you will not only make your place look better but also will free some additional space. Luckily, those who would like to have a small box deliver sufficiently high performance have a solution to go with: Mini-ITX platforms without embedded Atom processors but equipped with traditional CPU sockets that could take in the same contemporary processors as are currently used in the desktop systems. Quite a few mainboard manufacturers offer products like that today, and the number of models to choose from keeps growing, as it is very promising market.

However, it is important to keep in mind that it is still impossible to build a full analogue of a large high-performance desktop computer in a Mini-ITX form-factor. First, small system cases set serious restrictions when it comes to cooling systems, which means that far not any CPU or graphics card may be chosen for a Mini-ITX platform. Second, processors with low power consumption and heat dissipation are usually used in systems like that. These two factors determine mostly the base features of currently available Mini-ITX mainboards. In fact, there are two mainboard modifications that are available from most makers today: LGA775 mainboards based on integrated Intel or Nvidia chipsets, and LGA1156 mainboards based on Intel H57/H55 chipsets. These two platforms are especially suitable for Mini-ITX form-factor because value and mainstream LGA1156 and LGA775 processors boast considerably lower power consumption and heat dissipation than all other contemporary solutions.

Even though the solutions built around Intel processors dominate the market of miniature platforms, this uniformity is often disturbed by very successful offerings from Intel’s primary competitor. These AMD’s attempts to win a piece of the market use special energy-efficient CPU series, which are not so widely spread, but are indeed out there. There are a few modifications boasting low power-consumption among AMD Athlon II CPUs, which can be used in miniature computer systems. There are special Socket AM3 mainboards designed specifically for systems like that, even though they are not very numerous. For example, we have already reviewed Sapphire IPC-AM3DD785G Mini-ITX mainboard, which turned out a very interesting solution for a tiny system case when paired with an energy-efficient Athlon II X2 processor.

But today we are going to tell you about a different option for a Mini-ITX platform built from AMD components. We managed to get our hands on three energy-efficient Athlon II processors with two, three and four cores as well as a unique Mini-ITX Socket AM3 mainboard from Asus based on the AMD 880G chipset – Asus M4A88T-I Deluxe. Using all these components we managed to put together a high-performance miniature computer system, which seemed capable of competing successfully against LGA1156 systems of similar size. In fact, our today’s review is going to talk about the suitability of AMD components for fast, but at the same time small, quiet and energy-efficient computers.

Energy-Efficient AMD Athlon II Processors

AMD is still using pretty old 45 nm manufacturing process. Besides, their processor architecture can’t be called particularly energy-efficient. As a result, the power consumption of their major products is fairly high, according to today’s standards, and is even higher than the power consumption of Intel CPUs with similar performance. However, AMD found a way out of this situation by offering special more energy-efficient CPU models for those applications where low power consumption are heat dissipation are critical. The microarchitecture of these processors is not any different, and they are manufactured using the same production process, but they are built with carefully selected semiconductor dies capable of running at significantly lower voltages.

As a result, we can sort contemporary desktop AMD processors into a significant number of different groups based on their calculated TDP:

Obviously, the CPUs from the bottom part of the table suit better for quiet energy-efficient systems. Also, you should keep in mind that the chipset contributes a lot to the overall platform heat dissipation, therefore AMD’s energy-efficient processors with 45 W TDP seem to be the best choice for small Mini-ITX systems. The platform with these processors inside will have almost the same overall heat dissipation as dual-core LGA1156 Core i3 or Core i5 CPUs, which are pretty popular among Mini-ITX system builders today. Although these CPUs from Intel have 73 W TDP, the overall heat dissipation of systems built around them turns out pretty low due to the simple companion chip that consists of only one chip serving as a South Bridge. The calculations below explain it all:

The 10-watt difference can be eliminated for the following reasons. The calculated TDP as presented by AMD is very close to the practical readings that you can get off the CPU and the system. And if for some processors the TDP is claimed to be 95 W, it means that it in fact consumes (and dissipates) right about that amount of power in reality under maximum load. As for Intel, they use a slightly different way of calculating their processors’ TDP and allow slightly larger margins. As a result, the mass production CPUs from Intel consume (and dissipate) about 10% less power in real applications than stated in the TDP description.

AMD’s energy-efficient processor family with 45 W TDP includes a few models, which have a letter “e” at the end of the numeric index that stands for the model number. For our tests we selected three top models from the dual-, triple- and quad-core representatives of this family: Athlon II X2 250e, Athlon II X3 420e and Athlon II X4 615e. Their detailed specifications are given in the table below:

The specs seems to be pretty ordinary, which is actually not surprising at all, because they are based on the same semiconductor dies as the regular processors. Their power consumption and heat dissipation are in fact lowered using very straight-forward approach: by lowering the core voltage and the clock frequency. While standard Athlon II X4 and Athlon II X3 processors with 95 W TP have 1.425 V nominal Vcore, the core voltage of the energy-efficient models is limited by 1.25 V. Energy-efficient dual-core Athlon II X2 do not need their Vcore to be lowered that much, so they can work at up to 1.4 V core voltage. As for the clock frequencies, the 45 W Athlon II X4 and Athlon II X3 models are 600 MHz behind their 95 W counterparts, while the 45 W Athlon II X2 is 200 MHz slower than the regular 65 W analogue.

When we took a closer look at our specific units, we discovered that their actual Vcore is even lower than what we have just named:


Athlon II X2 250e


Athlon II X3 420e


Athlon II X4 615e

Obviously, the core voltage for a CPU is selected according to the features of the semiconductor die it is based on. We could prove it by measuring the maximum power consumption of our test samples under maximum load (created by LinX 0.6.4 utility), which they receive via their proprietary 12 V power line.

As we see, AMD falls very precisely into the claimed thermal envelope and 45 W CPUs consume exactly what they should, according to the spec. Since the models with different number of active cores have almost the same power consumption, their heat dissipation is also almost the same: when we measured the CPU temperature of our tested processors using the thermal diode under the CPU socket, all the reading were also extremely close.

In other words, it turns out that all AMD’s energy-efficient processors are similar to one another in power consumption and heat dissipation, however, they offer dramatically different performance, as they have different number of active cores and work at different clock frequencies.

Closer Look at Asus M4A88T-I Deluxe

While energy-efficient AMD processors are not very widely spread but pretty common products, we can’t say the same about Asus M4A88T-I Deluxe mainboard. Even without looking at its detailed specifications we can see that the developers have done a very thorough engineering job. They managed to fit almost the entire set of features typical of many full-sized mainboards into the Mini-ITX form-factor. In fact, we have already seen examples like that when we discussed miniature LGA 1156 mainboards from Zotac (Zotac H55-ITX WiFi) and Gigabyte (Gigabyte GA-H55N-USB3). But Asus M4A88T-I Deluxe is a truly unique product because it is the first multi-functional Mini-ITX Socket AM3 platform in the market.

However, a quick look at Asus M4A88T-I Deluxe is enough to see why it is true. Socket AM3 with the retention bracket takes up lion’s share of the PCB making all other components literally huddle in the corners. This is where Asus engineers really performed a feat: they managed to implement the functionality of a full—sized mainboard on a tiny piece of textolite. Asus M4A88T-I Deluxe even has a PCI express 2.0 x16 slot that can accommodate an add-on graphics card or any other devices with PCI Express interface.

There is another unique feature right next to the PCI Express x16 slot: it is a daughter card with a WiFi controller on it. In this case we have an 802.11n solution based on Ralink chipset and radio module. Unfortunately, this card connects to the mainboard via a modified USB port instead of a common connector, so you won’t be able to replace it with anything else without additional modifications.

Asus M4A88T-I Deluxe has very few internal connectors, which are quite numerous on full-size ATX mainboards. They are three SATA-300 ports with RAID support, and two USB 2.0 onboard pin-connectors. However, since Mini-ITX mainboards go into small system cases, this is not a big problem; it is much more important to have diverse external interface connectors instead. And this is where Asus M4A88T-I Deluxe really shines: the back panel of this mainboard has all sorts of connectors and ports and may undoubtedly become an object of envy for some full-size platform developers.

First of all I have to mention that there are two digital connectors for the monitors: Dual-Link DVI-D and HDMI. Asus M4A88T-I Deluxe mainboard is based on AMD 880G chipset that features an integrated Radeon HD 4250 graphics core. In most cases this core can provide sufficient functionality for a compact system: it supports hardware acceleration of HD video playback in popular formats and has 40 shader processors, which ensure that it also copes quite nicely with 3D graphics. By the way, I would like to draw your attention to the fact that this mainboard has only digital monitor outputs, so you won’t be able to connect any analogue displays with D-Sub interface even with a converter.

The mainboard also has an integrated sound card built on ALC889 codec that is why there are three analogue audio-jacks, and an optical and coaxial SPDIF on the mainboard connector panel. There is also a Gigabit network port, a PS/2 port for keyboard or mouse, eSATA port, four USB 2.0 and two USB 3.0 ports (blue connectors). Moreover, you can also find there a pair of antenna connectors for the Wi-Fi controller and a Bluetooth module antenna.

I doubt that you will ever regret having only one expansion card slot if you decide to pick Asus M4A88T-I Deluxe for your system. Everything you might ever need is already onboard. The only thing missing could be Firewire ports, but there are not that many devices using this interface anyway, and they are mostly scanners. Besides, someone may wish that this board had 6-gigabit SATA ports, which is also not an obvious drawback, because only very few premium-class SSDs can in fact utilize the bandwidth exceeding 3 Gbps.

The formal mainboard specifications look as follows:

Overall, Asus engineers have definitely succeeded in designing a small Socket AM3 mainboard with rich functionality. It is for a reason that this mainboard is part of the Deluxe series, which includes only the solutions with the richest functionality and features. However, this is when a logical question pops up: how did they manage to fit all of this onto a Mini-ITX PCB? As soon as you start digging into the technical details, the answer reveals itself. In order to save some space on the PCB, Asus engineers had to implement three solutions that do not leave you that excited anymore.

First of all, look at the memory DIMM slots. These are not the common DDR3 DIMMs, which couldn’t fit onto this board, but the short DDR3 SO-DIMM slots designed to accommodate memory modules for notebooks. Of course, SO-DIMM is not some kind of exotics, but modules like that are more expensive, and their frequencies and timings are usually worse than those of the conventional DDR3 SDRAM DIMMs.

Secondly, the processor voltage regulator circuitry didn’t remain untouched, either. Asus M4A88T-I Deluxe has a triple-channel voltage regulator circuitry, with a separate fourth channel dedicated to powering the Uncore part of the CPU.

Moreover, since there was not enough space on the mainboard PCB, the processor voltage regulator transistors were left without any cooling. Keeping in mind that contemporary AMD processors are not very energy-efficient, it created a problem, which forced Asus engineers to set certain restrictions to the list of supported processors. For example, this mainboard can only work with those CPUs, which TDP doesn’t exceed 95 W. and it means that top Phenom II processors cannot be used in Asus M4A88T-I Deluxe. The good news in this case is that AMD luckily has 95 W modifications for all of their processors, even including the six-core Phenom II X6.

Thirdly, the chipset also has no good cooling system. In order to resolve this situation, they moved the chipset North and South Bridges very closely to one another and used a single aluminum heatsink to dissipate the heat from both of them.

But taking into account that AMD 880G and AMD SB710 chips together dissipate about 23 W of heat, this heatsink seems to be too weak. It runs really hot at work, so we strongly recommend ensuring that it is in the way of some airflow inside your system case. And the best way would be to top it with its own individual fan.

Overall, the layout of Asus M4A88T-I Deluxe mainboard is not very convenient, although it would be extremely naïve to expect a convenient components layout from a Mini-ITX mainboard. When you build a system on this mainboard, you will have to put up with a small processor cooler (even a boxed CPU cooler can barely fit onto this board) and severely hindered access to the memory modules once the cooler is installed and the ATX power cables are connected.

However, as soon as you complete the assembly of your Asus M4A88T-I Deluxe based system (taking into consideration all our comments above) and turn on the system, you will be able to start praising this miniature mainboard again. The thing is that, Asus M4A88T-I Deluxe has a BIOS worthy of the Deluxe series products: it features all the functions and options typical, of Asus mainboards targeted for computer enthusiasts. In other words, the BIOS Setup of Asus M4A88T-I Deluxe has everything necessary for CPU overclocking as well as enabling the additional cores.

Overall, the BIOS functionality of Asus M4A88T-I Deluxe is pretty typical, and it looks like Asus engineers simply modified the BIOS of a full-sized Socket AM3 mainboard to fit the functionality of their Mini-ITX product.

In addition to the BIOS settings, Asus M4A88T-I Deluxe also has Core Unlocker and Turbo Key II hardware switches that allow unlocking the disabled CPU cores and overclocking the CPU without touching any of the BIOS settings in the Setup.

However, do not get too excited about these extensive overclocking-friendly options. As we have already mentioned the processor voltage regulator circuitry on this mainboard is designed for maximum 95 W power consumption rate. Therefore, you have to be very careful when you enable additional cores or overclock your processor and realize that any adjustment in the electrical or frequency settings does affect power consumption and may cause irreparable damage to the processor voltage regulator circuitry in the process. So, the benefit of having all these overclocking options is overrated. However, there is one truly useful feature: besides overclocking, Asus M4A88T-I Deluxe also allows lowering the system voltages below their nominal settings, which may have a positive effect on the temperature of the CPU and the entire system.

Testbed Configuration and Testing Methodology

Our goal was to build an energy-efficient high-performance Mini-ITX system using AMD components and check out its performance in comparison with the Mini-ITX platforms with LGA1156 processors. therefore, during our test session e are going to compare our Asus M4A88T-I Deluxe based system with different AMD CPUs inside against a system with Intel Clarkdale CPUs and a popular Zotac H55-ITX WiFi mainboard.

As a result, we ended up using the following hardware and software components during this test session:

Note that we used integrated graphics, which is more typical of the Mini-ITX systems. No external graphics cards were used.

Power Consumption

We would like to start with the power consumption tests instead of the performance tests, which usually come first in our articles. It is the power consumption tests that should tell us if it makes any sense to compare the systems using energy-efficient AMD processors, with two, three or four cores against platforms with dual-core Core i3 and Core i5 processors.

The graphs below show the full power draw of the computer (without the monitor) measured after the power supply. It is the total of the power consumption of all the system components. The PSU's efficiency is not taken into account. The CPUs are loaded by running the 64-bit LinX 0.6.4 utility. We used FurMark 1.8.2 utility to load the graphics cores. We enabled all the power-saving technologies for a correct measurement of the computer's power draw in idle mode: C1E, AMD Cool'n'Quiet and Enhanced Intel SpeedStep.

We have already pointed out before that systems built around AMD processors consume less power in idle mode. And in this case, energy-efficient processors from AMD managed to outshine the system with Intel inside quite substantially.

However, in case of high CPU utilization we see proof of what we have just discussed above: you will need to use only energy-efficient AMD CPUs if you want to build a system that would consume the same amount of power as dual-core Intel LGA1156 processors. Nevertheless, a Core i3-530 based system will still be the most energy-efficient option. The formal TDP of this processor is declared at 73 W, but as we see from the obtained results, the entire system consumes considerably less power, which indicates that Intel claims higher TDP for their processors, especially when it comes to the junior CPU models.

We also see pretty interesting results when the graphics core is also heavily utilized. As the number of cores in AMD processors increases, the total power consumption of the corresponding platform suddenly goes down. And there is no mistake here: as we will see later on, the performance of the integrated graphics core changes accordingly. As a result, the most energy-efficient combination for our ASUS M4A88T-I Deluxe would be AMD Athlon II X2 615e. As for the high power consumption readings taken off a system with Intel Core i5-661 inside, this CPU has an overclocked graphics core, unlike other Clarkdale processors.

When the operational load on all parts of the AMD platform is at its highest, it manages to remain at the level of an Intel Core i3 based system. On the one hand, this is a very good result, but on the other, we should still keep in mind that we had to use special energy-efficient CPUs to accomplish it. At the same time I would like to draw your attention to another interesting fact. The results suggest that a 100 W PSU may be more than enough for a pretty powerful Mini-ITX platform.

However, when we get to video playback, ASUS M4A88T-I Deluxe based systems perform real well. And this isn’t surprising at all. Al contemporary graphics cores accelerate HD video decoding without loading the system CPU, so that it remains almost completely idle during HD video playback causing the total system power consumption to be maybe 5-6 W higher than in idle mode.

Summing up the results of our power consumption tests I can conclude with all certainty that we picked the right AMD processors to compete against Intel’s LGA1156 Mini-ITX platform. Energy-efficient Athlon II CPUs do allow you to build a system with almost the same power consumption level as the systems with regular dual-core Clarkdale processors inside. Now it is time to move on to the performance tests.

General Performance

While in power consumption tests energy-efficient AMD processors proved quite capable of competing against dual-core LGA1156 rivals from Intel, the situation in performance tests is somewhat sadder. Dual-core LGA1156 processors are indisputable faster than any energy-efficient Athlon II CPUs, even including a quad-core model, in PCMark Vantage measuring the overall system performance, Photoshop CS5 graphics editor, WinRAR archiving utility or iTunes 9 software media center. In all other tests, only Athlon II X4 615e proves fast enough. For example, the quad-core Athlon II X4 620e works faster than Core i3-530 during HD video encoding using x264 codec, final rendering in Cinema 4D or chess play in Fritz benchmark. However, it can’t outperform a faster Clarkdale CPU – Core i5-661. In other words, Intel products offer better performance-to-power consumption ratio, even if we compare Clarkdale CPUs against energy-efficient AMD Athlon II processors, and not the regular ones.

Graphics Performance

However, even if the Mini-ITX platform from AMD is not as fast in processor tests, it has another trump to play: high-quality contemporary Radeon HD 4250 graphics core supporting DirectX 10.1 built into AMD 880G chipsets. Intel’s HD Graphics core inside Clarkdale processors supports only DirectX 10 and has image quality issues in many contemporary 3D games.

As for the performance of the integrated graphics cores, both our tested platforms showed the following results:

AMD platform performs very well in gaming tests. Sometimes, ASUS M4A88T-I Deluxe mainboard on AMD 880G chipset even manages to outpace Intel H55 based platform with Core i3 and Core i5 processors. And the fact that AMD platform uses slower processors doesn’t really affect the results of the gaming tests that much.

By the way, we often notice one very interesting effect in games: as the number of processor cores increases the gaming performance may actually drop. The reasons for that lie with the way the integrated graphics core works, as it uses part of the system memory for its needs. As a result, the GPU communicates with the video memory along the same bus as the CPU. But multi-core processors that do not have a shared cache also use the system memory to transfer data between the computational cores. Therefore, quad-core Athlon II X4 processors create bigger “parasitic” load on the memory bus than CPUs with fewer cores. As a result, the graphics core slows down, because in reality it gets less memory bandwidth, if the system has a CPU with multiple cores in it. To eliminate this issue AMD suggests using a special buffer called SidePort Memory on their mainboard, however, there simply wasn’t enough space for it on ASUS M4A88T-I Deluxe.

As far as Intel processors are concerned, the advantage of Core i5-661 over Core i3-530 can be explained by the fact that the graphics core of the former works at higher clock frequency, which is a peculiarity of this specific CPU model.

Conclusion

Overall, the Mini-ITX platform built on AMD components made a great impression. As our tests showed, it has every right to live a long a happy life. And although over a period of time we have been saying that Athlon and Phenom are synonyms to high power consumption, in reality it is not always like that. As we have just seen, you can build a very economical system with energy-efficient CPU modifications, and its total power consumption won’t exceed 100 W. And this system will demonstrate pretty competitive performance, especially when it comes to 3D games. In other words, AMD managed to achieve acceptable performance-to-power consumption ratio by downclocking their processors. That is why when you see new Mini-ITX mainboards for Socket Am3 platform, it is not a favor to the dedicated AMD fans, but a reality of the today’s market.

Moreover, do not forget that LGA1156 platform that is currently very popular among high-performance but at the same time compact solutions, is far not the most universal product. The thing is that only dual-core Core i3 and Core i5 processors have an integrated graphics core. And it means that an Intel Mini-ITX system with a quad- or six-core processor inside can only be built using an external graphics accelerator. And the latter will not only contribute to the system power consumption and heat dissipation, but will also need more free space inside the system case. Socket AM3 systems with integrated graphics are free from this conflict: their graphics core is inside the chipset so it can be used with multi-core CPUs. So, I am sure that some of the owners of miniature Socket AM3 mainboards will want to build a system with regular (not energy-efficient) 95 W Phenom II X4 or Phenom II X6 processors. And this choice is also absolutely justified.

As a result, the ASUS M4A88T-I Deluxe Mini-ITX mainboard we have just reviewed is not only an extremely interesting, but also a highly demanded solution. First, it is a unique product, because none of other mainboard makers offer miniature mainboards based on the current AMD chipsets from the 8th series. Second, this mainboard has extensive functionality, it supports external graphics accelerators, most contemporary interfaces and is even equipped with Wi-Fi and Bluetooth controllers. Third, this is a Deluxe series product, which means that it has everything necessary for overclocking processors and unlocking disabled CPU cores.

Of course, this mainboard does have certain drawbacks, the most frustrating one being the 95 W limitation set for the processor voltage regulator circuitry. However, even that won’t diminish the great job Asus engineers have done to present the users with a contemporary super-functional Socket AM3 platform in Mini-ITX form-factor.