The Promise of HD Graphics - Intel Core i5-661

The Promise of HD Graphics

2009 was supposed to be the year we got the first processor with an integrated graphics core on the chip package itself. Sort of like what AMD promised way back in 2008 for its Fusion initiative. Things however did not go according to the roadmap and we have been informed that it won't be till 2011 before Fusion becomes reality.

Unfortunately for AMD, its vision of a processing unit merging the CPU and GPU has now become reality for its biggest rival, Intel. Broadly speaking of course, since AMD's implementation of Fusion could very well differ greatly from what Intel is launching today. But the idea of integrating a graphics core with the processor, and not onto the motherboard as is traditionally done, is the same, at least from the consumer's point of view.

In fact, even Intel was promising this integration in 2009, with Havendale the codename for this family of processors, which would be based on Intel's current Nehalem CPU architecture. However, the company decided that its shift to 32nm production was moving along so well that it could afford to skip the 45nm Havendale and jump directly to its successor, codenamed Clarkdale.

That leads us up to today's launch of six new desktop models in the Clarkdale family. (Intel is releasing new mobile processors based on the same 32nm technology called Arrandale at the same time). All of them are dual-core processors using the LGA1156 socket and thus, even more so than the previous Lynnfield, CPU launch, are squarely targeted at the mainstream and business users. Like Lynnfield, these processors are equipped with Turbo Boost that will increase the processor clock speeds by quite a few bumps when dealing with applications

that are unable to use the full complement of processor cores. The Core i5 series of these Clarkdale processors also comes with HyperThreading to better deal with today's more multi-threaded environment. Below are the new models announced and some of their more relevant specifications.

As you may have noticed, while these processors are quite similar to Lynnfield (same amount of L3 cache per core, memory support and Turbo Boost), the integrated graphics core differentiates the two. Intel may have managed to shrink the processor core to 32nm, but the graphics, memory and the PCIe controllers (remember, since Lynnfield, they are now integrated with the processor cores) are still on a 45nm process. Therefore, if you ever peel open the Clarkdale processor's heat spreader package, you'll find two distinct dies as shown below:

So what are the advantages of having the graphics core integrated with the processor? The main issue here is cost, as according to Intel, moving from the three-chip package solution of the previous Intel architecture (CPU with Northbridge and Southbridge) to the two-chip package (CPU and Platform Control Hub) means a 30% savings in terms of the package area, which translates

into reduced manufacturing costs.

The other issue here, power savings, has more to do with the 32nm manufacturing process used for the processor component in the Clarkdale. For those who are counting, the graphics portion too benefits from going to 45nm since the previous X4500 series integrated graphics core on the G45 chipset for instance was built using a 65nm process. So it's likely that we'll see significant power savings with these new processors, especially when the maximum TDP rating for these new models is just 87W.

Finally, these new processors all come with a new x86 instruction set meant to improve the encryption/decryption speed for AES. Applications which benefit from the new instructions include file encryption utilities like Windows

' BitLocker.

For the review, we got the Core i5-661 from Intel. It appears to be the only model out of the six to have a 900MHz graphics core clock speed, which also means a higher TDP rating. Besides that, it is identical to the Core i5-660, except for some differences in features (the 661 lacks Intel vPro and VT-d support for instance). Both are priced at the same US$196 for 1k units so it appears that the 661 is the better deal for raw performance. Before we move on to the new Intel H55 Express chipset that supports these new Clarkdale processors, here is the CPU-Z info:

The Intel H55 Express Chipset

The second LGA1156 compatible chipset to be released, the Intel H55 Express chipset, has quite a few features in common with the P55 Express chipset. It's a single-chip solution, with the platform control hub (PCH) communicating with the processor via DMI (and not QPI like the Nehalem Core i7s). The presence of the graphics core on the Clarkdale processor meant that there's a new Flexible Display Interface (FDI) to handle the issue of transmitting the video signals such that they can be output via HDMI, DVI or even DisplayPort. This additional interface for handling video signals is one of the major differences between the H55 and the previously launched P55 chipset.

Both chipsets support dual-channel DDR3 memory (up to 1333MHz) though the PCIe and memory controllers are now both on the processor. Given its mainstream positioning, the H55 chipset is unsurprisingly only capable of supporting a single PCIe 2.0 x16 graphics card, unlike the P55 and its CrossFire/SLI capabilities. The number of PCIe Express x1 lanes have been slightly reduced to six from eight while the number of USB 2.0 ports supported are also cut by two. There's no USB 3.0 or SATA 6Gbit/s support but that's something that we had expected.

The Intel DH55TC Motherboard

From the marketing collateral provided by Intel and the design of the board itself, it's obvious that the company's 'reference' H55 motherboard is predictably targeted at the media-oriented consumer. The micro-ATX form factor coupled with its display outputs meant that it is eminently suited as a media center, with a Clarkdale processor presumably handling the graphics and HD playback. Obviously, one can fit a Lynnfield LGA1156 processor onto this board, though at the cost of not having the integrated graphics functionality.

The board itself is a rather conventional design typical of Intel, though it may initially appear to fall short as a media center for some users due to its lack of optical and coaxial S/PDIF outputs at the rear. There's an onboard header however for those who are willing to do the extra work. Of course, there's the small matter of the Clarkdale platform having support for bitstreaming of Dolby TrueHD and DTS-HD Master Audio via HDMI that should finally make all this audio angst redundant.

We had some minor issues with the layout and placement of certain onboard components, e.g. the single PCIe 2.0 x16 slot was definitely too close to the DIMM slots. As usual, we would also have liked our SATA ports to be aligned facing outwards instead of upwards but these are mostly minor preferences. For the majority of users, it's likely that they will be looking at third party products from the usual motherboard vendors for their H55 fix and not this Intel board. We'll be covering those in a future article.

HD Graphics Finally?

It's no Larrabee but going by the specifications provided by Intel for the new integrated Intel HD Graphics as the chipmaker calls it on the Clarkdale processors, Intel has certainly managed to get on par with the competition on quite a few standards and features. The most significant ones are the media features that are related to the playback and decoding of media. While the previous generation X4500 series had full hardware acceleration

support (DXVA) for VC-1, H.264/AVC and MPEG2, the newcomer will add dual-stream decoding, meaning picture-in-picture mode can be fully offloaded to the graphics core.

The new Intel HD Graphics adds support for dual HDMI outputs along with dual audio streams, so you can use both DVI and HDMI outputs from the H55 chipset over two displays. As mentioned earlier, another feature that is currently only on the Radeon HD 5800 series, bitstreaming of Dolby TrueHD and DTS-HD Master Audio via HDMI is now supported by the new Intel graphics, which should get HD enthusiasts hopes up. Finally, video color depth has been increased to 12-bit from 10-bit while xvYCC gamut is also supported.

While the support list does seem to justify Intel's 'HD Graphics' moniker, the core technology in the Clarkdale graphics core is based on the same architecture as the older GMA. As the above slide shows, there have been enhancements to bring it up to date and one can expect a slight boost in raw gaming performance, thanks to it having two more execution cores, a higher memory capacity and a higher maximum clock speed. Don't expect it to be more than a decent mainstream integrated graphics solution however.

Interestingly, the Core i5-661 is the only model at launch to come with the higher 900MHz graphics core clock speed while the others are at 733MHz. The xx1 in the model name is likely to indicate that it has a 900MHz core clock. Along with its other features or lack of (like Intel vPro), it's fair to say that this model is aimed at consumers while business users are being funneled to the Core i5-xx0 versions.

Mobile users get a bonus with the introduction of dynamic clock scaling (along with a switchable graphics option between the integrated Intel HD Graphics and a discrete graphics solution) on the Arrandale processor (basically mobile versions of the Clarkdale reviewed here today). This feature should be broadly similar to Turbo Boost, where the graphics core clock speeds vary according to workload. On paper, it should lead to power savings that translate to a longer battery life for mobile platforms, but that's another article for when we actually get our hands on such a notebook.

Test Setup

The Clarkdale Core i5-661 is the first dual-core processor from Intel's 32nm Westmere version of the Nehalem architecture that we have encountered and hence, we can only compare it to older dual-cores like the Core 2 Duo E8500 (3.16GHz) and recent, Lynnfield quad-cores like the Core i5-750. Since the Core i5-750 is retailing for around US$195, it would be a direct competitor if one excludes the integrated graphics on the 661. We have also thrown in scores from the Core i7-860, since it represents the next step up for the Lynnfield family of processors.

For the comparison, we have added in an quad-core, the Core 2 Quad Q9550 and the slowest Nehalem Core i7, the Core i7-920. From AMD, we have the fastest Phenom II currently, the Phenom II X4 965 'Black Edition', which at US$185 is also in the same price region as the i5-661. As we are concerned with the raw processor performance at the moment, we will be using the Core i5-661 with a discrete graphics card. There will be a section later in the review if you're only interested in the integrated graphics performance.

We have quite a few different platforms in our benchmarks but common to all are the following components (exceptions will be listed for each test setup):

• 2 x 1GB Kingston HyperX DDR3-1333 (CAS 7-7-7-20)
• Zotac GeForce GTX 260 (ForceWare 178.24)
• Seagate 7200.10 200GB SATA hard drive (one single NTFS partition)
• Windows XP Professional with Service Pack 2

Intel Core i5 (Clarkdale) Test Configuration

• Intel Core i5-661 processor
• 2 x 1GB Kingston HyperX DDR3-1066 (CAS 7-7-7-20)
• Intel DH55TC (Intel H55 Express chipset)
• Intel INF 9.1.1.1020 and Intel Rapid Storage Technology 9.5.0.1037

Intel Core i5/i7 (Lynnfield) Test Configuration

• Intel Core i5-750 and Core i7-860 processors
• Intel DP55KG (Intel P55 Express chipset)
• Intel INF 9.1.1.1015 and Matrix Storage Manager 8.9.0.1023

Intel Core i7 Test Configuration

• Intel Core i7-920 processor
• Gigabyte X58 Extreme (Intel X58 Express chipset)
• Intel INF 9.1.0.1007 and Matrix Storage Manager 8.6.0.1007

Intel Core 2 (LGA775) Test Configuration

• Intel Core 2 Duo E8500 and Core 2 Quad Q9550 processors
• ASUS P5E3 Deluxe (Intel X38 Express chipset)
• Intel INF 9.1.0.1007 and Matrix Storage Manager 8.6.0.1007

AMD Phenom II X4 Test Configuration

• AMD Phenom II X4 965 processor
• MSI 790FX-GD70 (AMD 790FX + SB750
• 
  

Benchmarks

The following benchmarks were used in this review:

• BAPCo SYSmark 2007 Preview (ver 1.05)
• Futuremark PCMark 2005 Pro
• Lightwave 3D 7.5
• 3ds Max8 (SP2)
• Cinebench 10
• XMpeg 5.03 (DivX 6.8 encoding)
• Futuremark 3DMark06 v1.1
• AquaMark3
• World in Conflict v1.05
• Crysis v1.1

Results - SYSmark 2007 Preview

In SYSmark 2007, the Core i5-661 had a very good start as it was very competitive with most of the quad-cores and was only beaten by the Core i7-860. Certainly, its relatively high clock speeds played a major role in its performance, helping it overtake its more expensive rivals.

Results - Futuremark PCMark05 Pro

The Core i5-661 continued to perform admirably in PCMark05, where it was on par with the older Q9550 and the relatively slow Core i7-920 (2.66GHz only). The Lynnfield processors however were still faster and this was more apparent in the memory segment, where the Core i5-661 emerged as expected as the slowest of the Nehalem-based processors.

Results - Lightwave 3D 7.5

While the Core i5-661 started off strongly in Lightwave 3D (Tracer-Radiosity) with the 2-threaded runs, its dual-core nature meant that even with the aid of HyperThreading, it was unable to compete beyond 4 threads. At the final 8-threaded run, the Core i5-661 only managed to beat the Core 2 Duo E8500. It was slightly more competitive in Sunset, where it edged out the Phenom II and the Q9550 when running 8 threads.

Results - 3ds Max 8 (SP2)

As expected, the dual-cores on the Core i5-661 meant that it was only able to beat the Core 2 Duo E8500 in this rendering benchmark (using the Light Tracer plugin). With the other plugin, the results were more unpredictable as we found the Core 2 Duo surprisingly the best performer. The Core i5-661 however remained behind the Lynnfield contingent.

Results - Cinebench 10 and XMpeg 5.0.3 (DivX 6.8 encoding)

As a dual-core processor with a decent clock speed and most of all HyperThreading, the results we saw in Cinebench 10 and XMpeg for the Core i5-661 were in line with our expectations. It was clearly ahead of the Core 2 Duo E8500 in Cinebench 10 but behind the last-gen Intel Core 2 Quad Q9550. The Phenom II was fared better here. XMpeg gave a similar result, though the Core i5 did manage to edge out the Phenom II while the Core i7-920 was surprisingly slow here.

Results - Futuremark 3DMark06 & AquaMark3

In 3DMark06, the Core i5-661 fell in behind the other quad-cores for the CPU segment and was ahead of the E8500. Overall, it was roughly equal to the Q9550 in this benchmark, which is quite decent for a dual-core processor. It was less impressive in AquaMark3 however, where it was finished last narrowly.

Results - World in Conflict & Crysis

Like the synthetic gaming benchmarks, the Core i5-661 lagged behind the quad-cores in the two games tested here. It even failed to match the other dual-core, the Core 2 Duo E8500, though the E8500 does have slightly more L3 cache than the Core i5-661.

Power Consumption

What do you get with a new dual-core processor made using a 32nm manufacturing process? Lower power consumption obviously. It's the most significant aspect of these new processors and the Core i5-661 showed that in our tests. At idle, it was easily the lowest in terms of power draw, though against its quad-core rivals, that's not too difficult. This remained the case even when we started running applications and the Core i5-661 beat its dual-core predecessor, the Core 2 Duo E8500 handily with lower power consumption figures.

Test Setup

Intel's previous integrated graphics chipset, the X4500 series was unable to play Blu-ray discs on Windows XP. This was apparently due to content protection issues, which meant that one had to be on Windows Vista or 7 for the Blu-ray playback to work. It's the same for this new HD Graphics on the Clarkdale/H55. So if you're somehow still on Windows XP, you'll need to either change the hardware or upgrade your OS.

Since our CPU testing was conducted on Windows XP, we had to use a slightly different setup and comparisons for the next part of the benchmarks, this time focusing on the integrated graphics. Windows 7 retail was chosen as the OS while we decided to compare our Core i5-661/H55 setup against other integrated graphics solutions out there, including its predecessor, the GMA X4500HD equipped G45. NVIDIA's GeForce 9300 and AMD's 785G are the other contenders.

Next, due to platform differences, we couldn't use the same processor for all the tests, so the alternative is to approximate a similar class of processor to keep things as equal as possible. For the NVIDIA and Intel G45 setups, we have gone with a Core 2 Duo E8500 processor while for the AMD system, we opted for a similar dual-core Athlon II X2 250. Although the Core i5-661 is the superior processor in terms of performance and technology to the other processor options, we decided that for these graphics benchmarks, the CPU is probably not the most significant component.

All the systems used the same Seagate Barracuda 7200.10 hard drive and the latest graphics drivers for their platforms. (Catalyst 9.11, NVIDIA ForceWare 195.62, Intel GFX_15.16.2.1986 for the G45 and Intel GFX_15.16.4.x.2009_PV for the Core i5-661).

CyberLink Power DVD 9 was used for Blu-ray playback but the beta version that Intel provided (with support for Clarkdale), version 9.0.2201 was quite erratic in our testing, crashing often when Blu-ray playback was started. Hence, once we got our results for the Intel Core i5-661/H55 setup, we swapped to an older version, 9.0.2010 for the other comparisons. Two Blu-ray movies, Black Snake Moan (encoded with H.264) and Superman Returns (VC-1) were used.

Blu-ray Playback

Despite the additional media features on the Clarkdale system, the CPU utilization for our Blu-ray playback tests was significantly higher than the others. Given that the X4500HD on the G45 produced better results with its inferior specifications, we have to attribute this to the beta nature of the CyberLink PowerDVD application and the drivers provided.

Overall, NVIDIA's GeForce 9300 integrated graphics solution had the lowest CPU utilization, though it does have a pretty solid processor compared to say the Athlon II X4 250. Besides our previous IGP comparison had showed that the AMD 785G is competitive with NVIDIA's equivalent given the same processor.

Gaming Benchmarks

The new Clarkdale Core i5-661 may indeed have a better graphics core, but from our Quake 4 results, it only showed a minor improvement over the GMA X4500HD. The NVIDIA GeForce 9300 with the Core 2 Duo E8500 was significantly faster still. The Core i5-661 fared better in Unreal Tournament 3, where it managed to trump the AMD 785G. Again, NVIDIA's GeForce 9300 had the edge.

Conclusion

As the first processor to have its graphics core right beside it, Clarkdale can be a bit underwhelming when it comes to its key feature - graphics. Of course, expectations should be lowered instantly on seeing its 0'integrated' nature, more so when the graphics architecture is a third-gen evolution of Intel's familiar Graphics Media Accelerator.

From a pure performance point of view, the new Intel HD Graphics is a slight upgrade over the GMA X4500HD, even in its fastest (900MHz) incarnation on the Core i5-661. What it does significantly better is media playback, where it certainly manages to justify its HD tag. Our Blu-ray playback may not have been very impressive, but the beta nature of both the drivers and the CyberLink application means we won't be nitpicking in this area to pass a judgment this round.

Besides, CPU utilization is not such a big deal for users once there's no discernible lag like what we experienced with the i5-661. Unless you're watching a movie and rendering some animation or encoding videos in the background, in which case we recommend a dedicated graphics card with a quad-core processor. Instead, other features like dual-stream decode, dual HDMI output support and for true HD enthusiasts, bitstreaming of audio CODECs matter more. These are all found on the Intel HD Graphics and arguably put it on par with its rivals when it comes to media playback needs.

As a processor, the dual-core nature of the Core i5-661 meant that it was rarely going to challenge the higher-end quad-core processors, even with Turbo Boost and HyperThreading. Most of its better scores were naturally recorded for system suites like SYSmark 2007 and not heavily multi-threaded applications. In fact, from some of our benchmarks, we can't help but wonder if the smaller L3 cache on the Core i5-661 affected its performance compared to the older Core 2 Duo E8500. Plus, the memory controller located off the main CPU die might add on to latency that could show up on more intensive tests, such as our memory testing in PCMark Generally, one would rank the Core i5-661 below the Core i5-750, which would appear to be the case based on Intel's own nomenclature.

This brings us to its cost. With a US$196 price tag for 1k units, the Core i5-661 will likely be competing against Intel's own Core i5-750. And like we said, it won't surpass the quad-core. Still, we hope the new H55 motherboards are competitively prices to give these new Clarkdale processors more value. Already, unlike the i5-750, the i5-661 has a decent mainstream graphics core inside, which should be adequate for some users, including businesses. Not forgetting the impressively low power consumption figures we recorded at both idle and peak loads.

Therefore, there's certainly a place in Intel's rank for these new Clarkdale processors such as in large business organizations. Media theater enthusiasts too should be among those eagerly awaiting these processors. For consumers who have a decent desktop or a HTPC setup already, there's much more potential in the mobile version, Arrandale, which we will hopefully cover in depth once we get some hands-on with an actual unit.

Our articles may contain affiliate links. If you buy through these links, we may earn a small commission.