Intel Atom vs. VIA Nano Platform Comparo

Atom and Nano are the most power efficient CPUs on the market. Today we see who has the most impressive platform.

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15 minutes & 54 seconds read time


Intel Atom vs. VIA Nano Platforms

When we think of the CPU in our systems today, we think of high powered Core 2 processors or a cheaper Phenom in order to power our gaming systems of the day. These two processors are fighting it out for the top of the performance ladder and a battle it has become.

While we concentrate on this sector, the focus is now moving towards the lower end of the spectrum. VIA has really cornered this market in the past when it came to ultra compact PCs; EPIA has been VIA's biggest success and with the evolution of the VIA processors, each generation has gotten just that little bit more capable. Now Intel has seen just how popular this is, we finally have some competition in this sector.

Until recently the C7 processor defined performance at lower power consumption, but not to be outdone, Intel released at Computex 2008 its introduction to take on VIA; the Atom series processor. However, VIA wasn't going to let Intel win here, and at the same time announced its latest update to its processor range; the Nano.

Today we will be pitting the Atom platform against the Nano platform. Who has the best performance and energy savings? - Well, we don't know yet, but by the end of this we will have an informative answer to that. Let's move on and check out the platforms individually before we get into the testing phase.

Atom Platform

Introduction to Atom

Intel Atom vs. VIA Nano Platforms

Atom is Intel's first processor aimed at the low power market; similar to how VIA introduced its C3 and C7 to take on these markets some time ago. The main aim for Atom is for the Mid, UMPC and HTPC environments; designed to consume as little power as possible while keeping some form of processing power onboard.

Atom is a new breed of CPU from Intel in that it is a totally new design. This is something interesting as we have seen that the Pentium-M processor was a re-design of the Pentium III processor, and even the Core 2 architecture has a lot of the Pentium-M in it. Atom is the first in-order processor to come out of the chip giant since the old 586 architecture, which makes it something you're not going to want to do media encoding on.

First off, let's have a look at the platform that each come in. The Atom is based around a mini-ITX motherboard layout, which is good for the industry. At Computex 2008 we were told that Intel was pushing for a new standard that was about 18 or 19cm rather than the 17x17 that mini-ITX runs. Somehow I don't think Intel wanted to be seen following VIA. Either way, though, it looks like either Intel either saw the light (not likely) or was pressured into using it by the big names out there who already have interest in mini-ITX. While they have given in on that part, Intel has given a huge amount of strict guide lines that companies have to follow to make an Atom based board.

First off, no digital components. What we mean by this is, simply, there is to be no digital video components such as DVI or HDMI output or digital audio outputs like Toslink or RCA S/PDIF. So, it's bye bye HTPC for this one.

Next is audio; only AC'97 audio is allowed. HD Azalia Audio is crossed out here. Lastly, only one memory slot is resident, making it hard to get any real performance out of it.

A testament to the power savings of the Atom is the single phase voltage regulation system that the CPU needs in order to get its power. Atom is extremely power efficient compared to any other Intel CPU ever made. The boards expansion system consists of a single PCI slot; there are no current generation slots available.

Intel Atom vs. VIA Nano Platforms

Now, let us introduce you to the Atom itself. This is what the CPU looks like under the heatsink. The Atom is extremely power efficient and therefore runs very cool; so cool in fact that it only requires passive cooling. We measured its temperature through our heat gun when under load; with the heatsink attached we saw it get to just 38c. That's extremely impressive.

Atom is the first in-order processor made from Intel since the Pentium 586 series. This processor is not aimed at breaking SuperPI world records; its aim is to try and replace VIA as the number one in energy efficient computing and hopefully steal some sales from VIA's embedded market.

The Atom comes clocked at 1.6GHz with a 533MHz FSB. The same bus used for the P4, Core 2 and even the C7 processor is used to increase the amount of data transfer between the CPU and MCH. 512K of L2 cache makes up the CPU on-die memory, which for a low power unit makes it extremely impressive.

While the Atom has only a single core, a familiar technology returns to help Atom make use of any un-used CPU cycles per clock. I am speaking of Hyper Threading. Those of us who remember the Pentium 4 processor will remember HT technology. This allows a single physical processor to be detected as two logical units, allowing more instructions per clock to be executed. As one instruction is leaving the CPU, the second doesn't have to be sent from memory to the data bus; it's already in the spare cycles being completed.

While you may think this CPU is cut down on features, it's far from the truth. Atom features SSE, SSE2 and SSE3 instruction sets along with EM64T, so yes, it can run Windows XP 64 and Vista 64, though how well it will do this is another thing.

All of this is produced on a 45nm High-K silicon die, the same transistors that make up the Penryn based Core 2 are used to give this CPU a TDP of 25 watts at max load.

Intel has chosen not to imbed a chipset into the CPU, so this is left to an external solution. What Intel has chosen to use is a rather outdated chipset by our standards. However, Intel doesn't want Atom to overshadow its high-end products. To this end, the i945GM chipset is given a re-birth as the Atom platform. The issue with this chipset is that it is quite power hungry for a system that Intel is aiming for low power consumption; it's said that the i945GM can use between 20 and 25watts, which is almost as high as the CPU itself. While the chipset can support dual channel memory, Intel is limiting this to single channel for Atom partners. Why they have done this is anyone's guess. Maybe Intel is waiting for something before opening its doors fully in this market segment.

The i945GM has the built-in GMA950 IGP. This is quite an old graphics system, even for the Intel standard which has now moved into the GMA X4500. First off, this IGP requires system memory and with only one memory slot, you're going to be losing between 64MB and 256MB, depending on how the dynamic memory system decides to deliver the memory around. With one slot, a max of 2GB memory is supported, so prepare for some system hits. Unfortunately, the GMA950 lacks any DX10 support as well as support for HD video decoding, so we will be interested to see just how well (or badly, I should say) it plays back some 720p and 1080p videos.

Accompanying the 945GM is the ICH7. This Southbridge may be aging but it still supports all the major features of today. There SATA-II interface is included for four ports, though only two are used on the Atom platform. HD Audio support is also there, but it's thrown out the window since AC'97 is the only option Intel allows. PCI-E lanes are also resident through the ICH7, but again we won't see that happening for some time. Finally, there's the inclusion of 10/100 Ethernet which is the only network standard allowed for Atom.

In all, Intel has really set the Atom back with its limited hardware choices.

Nano Platform

Introducing Nano

Intel Atom vs. VIA Nano Platforms

Now it's time to take a look at the competitor to Atom. While Intel was hoping that it would only have to deal with C7, VIA had other ideas. At Computex, the very same place Intel revealed Atom to the world, VIA introduced Nano. VIA's aim for Nano is the same as Atom, it's designed to replace the C7 as the top of the energy efficient heap while improving its overall processing power.

Intel Atom vs. VIA Nano Platforms

VIA sent us their reference design Nano platform which is simply a VIA EPIA-SN that we reviewed not long ago, but the C7 was removed and the Nano added. That's the beauty of Nano, it's totally pin compatible with C7, so any board running a C7 can simply have a Nano added in its place; no other changes apart from a BIOS update is needed.

Intel Atom vs. VIA Nano Platforms

While Intel went with a single phase voltage regulation system for the Atom, VIA adds in three phases. While it's not needed, it allows the board to run even cooler as the components don't have to do as much work. In fact, with three phases we didn't get a heat reading off the voltage units above 28 degree Celsius; a very impressive result.

Intel Atom vs. VIA Nano Platforms

To VIA's advantage, they have managed to do away with the old PCI interface and have a single PCI Express x16 slot supporting PCI-E 2.0, which means you can use any PCI-E devices in it or simply go with a dedicated graphics card taking more load off the CPU and IGP.

Intel Atom vs. VIA Nano Platforms

But that's not all. If you are one to want wireless networking, a mini-PCI slot is located on the back of the board, which can connect any mini-PCI device, including TV tuners. So, you're good to go here. Also on the back is a Compact Flash media slot. If you really want to, you can use this as a boot device with Windows or Linux Installed on it, reducing boot times significantly, especially with a 266X CF card. Imagine booting XP in just under 8 seconds in a nice compact little unit.

Intel Atom vs. VIA Nano Platforms

VIA's Nano CPU is a new architecture built on what was already known from the C7, but with new power management technologies and a totally new way of going. The Nano is an out-of-order processor, like the Core 2 and Phenom, allowing it to process instructions out of a specific order to achieve the same end result. This gives the CPU a boost when compared to the older in-order design which the C7, C3 and Atom are based on.

To match the Atom's 64-bit capabilities, VIA has also added X86-64 instruction sets to allow the Nano to work under XP 64 and Vista 64, so no one is missing out when buying a Nano over Atom. One thing that VIA has over the Atom is a 128-bit wide instruction execution engine, similar to what the Core 2 based on the Penryn architecture has. This allows the CPU to complete a single SIMD instruction in 1 clock cycle, where the Atom needs 2 cycles to do the same instruction, allowing the Nano to move to the next instruction where Atom is still on the end of the first.

Nano is based on a 65nm process, which is larger than what Intel is currently using. However, its TDP is only 25watts at 2GHz, which is better than the Atom which uses 25watts at 1.6GHz. Since the CPU is pin compatible with the C7, it uses the same V4 bus or the P4 bus as it's actually known. It's the same bus that Core 2, Pentium 4 and Pentium-M all share. The current generation run at 800MHz FSB, where future generations can increase to 1333MHz. On the cache side of things, VIA has it all over Intel once again with 64K L1 cache and a total of 1MB of L2 cache.

Last on the list is something we would have expected to see in high-end CPUs, but VIA has gone and added it to the Nano; that being Virtualisation Technology or Vanderpool Technology as it's known from Intel. This allows the CPU to do hardware emulation for Virtual PCs, giving V-PCs a better feel and response time.

Intel Atom vs. VIA Nano Platforms

To match up the VIA Nano for maximum experience, VIA has used its newest chipset, the CN896 Northbridge. This chipset was used for the EPIA-SN and C7 combination; it not only adds support for the C7 and Nano, it also has a dual channel memory controller for DDR2 modules, allowing for a total of 4GB of memory in a 128-bit array; a far better approach to the Atom series. Not only this, but a PCI Express 2.0 bus for the single graphics card slot give it the latest in PCI-E speeds, allowing new generation graphics cards to be used at their full speed. The CN896 also incorporates an IGP from S3 called the Chrome9 HC. This IGP also lacks DX10 support but does include on-die decoding of HD video in 720p; a big advantage for HTPC users, that's for sure. Unfortunately, the EPIA-SN doesn't include any DVI or HDMI output, but this could be changed in later revisions.

Intel Atom vs. VIA Nano Platforms

VIA's newest Southbridge, the VT8251 finally replaced the VT8237A which has lingered around for too long. The VT8251 finally adds four SATA II ports, PCI Express connectivity (which is used for the onboard Gigabit LAN) as well as HD audio. This is another advantage to VIA Nano; it has HD audio support and uses it.


Intel Atom vs. VIA Nano Platforms

Being ultra low power platforms, we weren't expecting any overclocking features on the boards. To this end, though, we weren't disappointed that both platforms lacked this ability, as they aren't designed to attract the overclocking crowd.

Important Editor Note: Our maximum overclocking result is the best result we managed in our limited time of testing the motherboard. Due to time constraints we weren't able to tweak the motherboard to the absolute maximum and find the highest possible FSB, as this could take days to find properly. We do however spend at least a few hours overclocking every motherboard to try and find the highest possible overclock in that time frame. You may or may not be able to overclock higher if you spend more time tweaking, or as new BIOS updates are released. "Burn-in" time might also come into play if you believe in that.

Test System Setup and Memory Performance

Test System

Memory: 2x 1GB DDR2-1186MHz Geil (Supplied by Geil) and 1x 2GB DDR2 Generic
Hard Disk: 500GB Western Digital SE16 (Supplied by Western Digital)
Graphics Card: GIGABYTE 9800GX2 (Supplied by GIGABYTE) and IGPs
Operating System: Microsoft Windows Vista SP1
Drivers: Intel INF Beta, VIA Hyperion, Forceware 175.16

Today's tests consist of two different setups. First off, we have our Atom test bed using a single 2GB generic 800MHz memory module. Next, we have the VIA Nano running 2x1GB modules in dual channel to make up the same 2GB.

All systems were tested with the IGPs running the maximum amount of system memory to the IGP. And just for fun, we threw the 9800 GX2 on the Nano platform to see what it is capable of.

EVEREST Ultimate Edition

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EVEREST Ultimate Edition is an industry leading system diagnostics and benchmarking solution for enthusiasts PC users, based on the award-winning EVEREST Technology. During system optimizations and tweaking it provides essential system and overclock information, advanced hardware monitoring and diagnostics capabilities to check the effects of the applied settings. CPU, FPU and memory benchmarks are available to measure the actual system performance and compare it to previous states or other systems.

Intel Atom vs. VIA Nano Platforms

Intel Atom vs. VIA Nano Platforms

Starting on memory performance, we get a look at just how well the Atom and Nano process memory bandwidth. VIA's dual channel approach allows it to get quite a bit more memory bandwidth than Atom which is stuck using single channel. This can be rectified by Intel allowing the second channel on the 945GM chipset. However, this isn't going to happen any time soon.

Using the discrete graphics option on the Nano allows for better memory performance, as all the memory is available for CPU usage and isn't being shared with the IGP.

Benchmarks - PCMark Vantage

PCMark Vantage

Version and / or Patch Used: 1.01
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PCMark Vantage is the first objective hardware performance benchmark for PCs running 32 and 64 bit versions of Microsoft Windows Vista. PCMark Vantage is perfectly suited for benchmarking any type of Microsoft Windows Vista PC from multimedia home entertainment systems and laptops to dedicated workstations and high-end gaming rigs. Regardless of whether the benchmarker is an artist or an IT Professional, PCMark Vantage shows the user where their system soars or falls flat, and how to get the most performance possible out of their hardware. PCMark Vantage is easy enough for even the most casual enthusiast to use yet supports in-depth, professional industry grade testing.

Intel Atom vs. VIA Nano Platforms

Moving into system tests, we see that the VIA Nano has over 300 more marks than the Nano. With the IGP disabled and the 9800GX2 enabled, it manages over 1000 marks more, making it a superb platform.

Benchmarks - Media Playback

MPEG-2 Playback

For MPEG-2 playback tests, we ran The Matrix DVD, a personal favourite of mine on each system with Hardware Acceleration enabled to check for smoothness of playback as well as CPU usage during the test. The result was with 30 minutes of playback and the CPU utilisation is the average.

Intel Atom vs. VIA Nano Platforms

Both setups played MPEG-2 video flawlessly; there was no dropped frames seen and the audio was sync'ed through the whole process. So, we consider it a success for both platforms.

On the CPU usage side, both systems managed to run around the same 15% with the VIA and 9800GX2 going down to around 11% thanks to the dedicated engine on the graphics card taking the decoding away from the IGP and system memory.

MPEG-4 Playback

Playback for MPEG-4 was again done with the Matrix, only encoded down to MPEG-4 DIVX 6.8 codec. 30 minutes was the time run. Smoothness of playback, audio sync and CPU usage are the keys here once again.

Intel Atom vs. VIA Nano Platforms

Here is where VIA gets a leg up on Intel, While both systems were able to playback the MEPG-4 video without jittering or audio sync problems, the VIA CPU never broke 25% usage, where the Atom was over 60% usage, this meant that if we tried to multi task, it would sometimes lag up the video for a second on Atom, VIA had no problems opening a Web page or loading Email.

HD Video Playback

This is the big one for the platforms. We downloaded a random 720p video to test out using Media Player 11. Again, quality of video playback, audio sync and CPU usage are the big things to focus on here.

Intel Atom vs. VIA Nano Platforms

A big win to Nano here. Atom was lagged all the way through; there was audio sync problems and video jitters. In fact, it was more like watching a slideshow of pictures on Atom with its CPU usage going right up to 98% where VIA managed to run at no more than 60% without a hitch.

Benchmarks - Crysis


Version and / or Patch Used: 1.1
Timedemo or Level Used: Custom Timedemo
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From the makers of Far Cry, Crysis offers FPS fans the best-looking, most highly-evolving gameplay, requiring the player to use adaptive tactics and total customization of weapons and armor to survive in dynamic, hostile environments including Zero-G.

Real time editing, bump mapping, dynamic lights, network system, integrated physics system, shaders, shadows and a dynamic music system are just some of the state of-the-art features the CryENGINE™ 2 offers. The CryENGINE™ 2 comes complete with all of its internal tools and also includes the CryENGINE™ 2 Sandbox world editing system

Intel Atom vs. VIA Nano Platforms

VIA showed at Computex its Nano setup playing Crysis with a dedicated graphics card. We wanted to replicate this.

With the Nano and 9800GX2, Crysis played at 1024x768 with medium level graphics settings quite comfortably. We were more than impressed that this was possible. It's not surprising that the IGP setups didn't have a chance, though.

Benchmarks - Power Usage and Heat Output

Power Consumption

We are now able to find out what kind of power is being used by our test system and the associated graphics cards installed. Keep in mind; it tests the complete system (minus LCD monitor, which is plugged directly into an AC wall socket).

There are a few important notes to remember though; while our maximum power is taken in PCMark Vantage in this instance at the same exact point, we have seen in particular tests the power being drawn as much as 10% more. We test at the exact same stage every time; therefore tests should be very consistent and accurate.

The other thing to remember is that our test system is bare minimum - only a 7,200RPM SATA-II single hard drive is used without CD-ROM or many cooling fans.

So while the system might draw 400 watts in our test system, placing it into your own PC with a number of other items, the draw is going to be higher.

Intel Atom vs. VIA Nano Platforms

VIA claims noticeable power savings over Atom and they are correct. With a superior architecture and larger transistors they are able to keep under the power envelope of the Atom. I wonder what will happen when VIA goes 45nm?

Heat Generation

As a new measure, we are now monitoring the heat generation from the key components on the motherboards, this being the Northbridge, Southbridge (if it contains one) as well as the Mosfets around the CPU. The results are recorded at idle and load during the power consumption tests.

Intel Atom vs. VIA Nano Platforms

Lastly, we look at heat and VIA managed to again beat Intel here. Surprisingly, the 945GM chipset generated more heat than the Atom CPU, yet VIA was able to beat them all. It seems VIA has worked on power and heat management across not only their CPUs, but chipsets as well.

Final Thoughts

Well, it's clear the battle for the budget and low power PC market is on. VIA has had driven this home for some time with its EPIA motherboards and now it looks like VIA is able to really push this with Nano. While it may have seemed like VIA finally had some competition, Intel really hasn't given us much to get excited about.

It's nice to see Intel has taken up the challenge to introduce a power efficient CPU like Atom with a companion chipset platform. However, a little more thought could have gone into its R&D. First off, the in-order design of the CPU severely limits its processing abilities. Its single channel memory approach really cripples it as well, especially when the IGP has to suck a portion of the system memory and bandwidth in order to operate. Add to this the limiting of peripherals with 10/100 Ethernet only and no HDMI or DVI-out for the IGP, making the Atom a bit too constrictive for a real HTPC market.

Bringing our attention onto VIA; they've done it again. Though, not surprisingly, they have had over six years to perfect the mini-ITX standard as well as having quite a long time to refine the CPU process to increase its processing power without raising the amount of power drawn. In fact, Nano doubles the performance of C7, adds 64-bit instructions yet consumes less power.

The platform for the Nano is extremely flexible. VIA hasn't put any constraints on itself with DVI and HDMI being possible as well as discrete VGA, HD audio and Gigabit LAN inclusions and a plethora of expansion possibilities with the CF card and Mini-PCI slot. VIA undeniably has a winner on its hands here.

Intel Atom

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VIA Nano

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