Thursday, December 10, 2009

The Perfect HTPC Graphics Card

Are you still hunting for the best graphics card for your HTPC? Well, you are not alone! Many enthusiasts are still searching out there for the perfect graphics card. Why does this search never end? The answer to this has got to do with the varying factors which people take into consideration while choosing their HTPC card. Sooner, rather than later, they realize that one of the factors they initially didn't consider as really important comes back to bite them.

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As a consumer who has tried out and experimented with offerings from all the 3 leading graphics card manufacturers, I can tell you that that every manufacturer has an advantage in some aspect or the other. This post will dwell in detail on the two major components of the HD HTPC experience, namely, video and audio. At the end of the post, I will also examine miscellaneous aspects which affect the consumer choice.

Read on for an in-depth look at choosing the right Video Card for your HTPC

1. Video Codec Support:

The perfect HTPC graphics card would provide hardware acceleration for all video codecs available. Unfortunately, that is an utopian dream. None of the graphics card available in the market accelerate RMVB (Real Media Video). Support for H.263 (Sorensen Codec) is limited (Even though it is available as a decoder profile in DXVA 2.0, I am yet to find a player which implements hardware acceleration for this codec). Thankfully, HD video (which most older CPUs have trouble decoding, and which you really need hardware acceleration for) is rarely available in these formats.

HD media is usually encoded in MPEG-2 (in the old HD-DVDs / Blu-Rays), H.264 or VC-1. When purchasing a HTPC card, ensure that it provides hardware acceleration for at least these 3 codecs. In addition to the underlying acceleration, it is necessary to have a software player which can parse the container (M2TS or MKV or anything else) and feed the video bitstream to the GPU. Discussion of the software players is outside the scope of this blog post.

a. ATI:

ATI's GPU-assisted hardware decoding is marketed under the term UVD.
HIS Radeon HD 3870 H387QS512NP IceQ3 Video Card

The quick summary is that all ATI cards from the Radeon HD 3000 series onwards support hardware acceleration of all the three codecs. Everything seems hunky-dory here, and you expect ATI to emerge as the winner. Even a cheapo 3450 like the ASUS Radeon HD 3450 would help you out if choosing a ATI GPU purely on the basis of video codec support. (Assuming fancy picture-in-picture features are not really necessary).

Unfortunately, codec support from the marketing documents is not the whole story. We will come to how it fares in the hands of the real consumer a little bit down the line.

b. NVidia:

NVidia's GPU-assisted hardware decoding is marketed under the term Pure Video.

While ATI's nomenclature for its products clearly indicate the UVD version supported, NVidia's is not straightforward. Instead of trying to summarize the features supported by each and every NVidia GPU, I will leave it to you to look up whatever GPU you are interested in, in this document. If the 'VDPAU features' column against your choice says 'A', you have landed yourself complete acceleration for H264 and partial acceleration for MPEG-2 and VC-1 (not enough for most common software players to take advantage of). If it says 'B', there is complete acceleration for MPEG-2, H264 and VC-1. With 'C' in the VDPAU features column, MPEG-4 / DivX videos can also be completely accelerated (Something noticeably absent in the ATI GPUs). If you are the type of enthusiast who likes to read about macroblocks and decoding profiles, NVidia gives a comprehensive technical document here. Even though the above NVidia links refer to features available on the Linux drivers, they translate directly into the features available on the Windows drivers for the same GPU.

Choosing a NVidia card on the basis of video codec support with the help of the above links now becomes very easy. The GeForce 210 models, which are available cheaper (after rebates) than the ATI 3450 (which is actually 2 generations old now) become the ideal choice. Of course, I am comparing apples and oranges here (the GeForce 210 vs the ATI 3450), but NVidia wins the video codec support hands down even when compared with the ATI 5000 series which costs 20 times as much (as of Dec  2009). Admittedly, the 5000 series cards from ATI are geared towards the gaming market, but we are talking about the HTPC enthusiasts here, and suffice to say that NVidia's latest generation cards are better than ATI's latest offerings as far as we are concerned in this section.

If not for the marketing blunder (which causes so much trouble for the consumer in choosing the card which fits one's requirements), NVidia would have won hands-down. On the other hand, NVidia GPUs have another trick up their sleeve which earn them much appreciation from the HTPC enthusiasts. More on this at the end of this section.

c. Intel:

Intel might not seem to be that great a name as far as graphics is concerned. But, the truth remains that it holds the largest graphics card marketshare. How come? The Intel IGPs are bundled with almost every PC chipset that you can imagine. For most people purchasing a ready made computer out there, it is the Intel IGP driving their monitors.

Intel woke up pretty late in the game to realize the fact that the consumers wanted hardware acceleration for video decoding. The initial offerings were pretty weak, but with the X3500 (which supported full MPEG-2 and partial VC-1 acceleration), things started improving. The 4500HD and its mobile variant released in mid-2008 enabled complete acceleration of the decoding of all 3 major formats. However, the problem with Intel's offerings is the fact that it remains very difficult for the software infrastructure to take advantage of the capabilities of the hardware. In fact, there is no acceleration when using Windows XP. DXVA 2.0 is the medium used to expose the hardware acceleration and it is available only on Windows Vista and Windows 7.

So, we have all three major vendors supporting full decode acceleration of all the major codecs. How do we choose between them? The discerning enthusiast tries to push the hardware to the maximum possible limits (beyond the official Blu-Ray specs) and expects support from the manufacturer in doing so (whatever platform he opts to be on). This is where NVidia pulls far ahead of the competition.

Enthusiasts who don't have the patience and time to rip their own Blu-Ray / HD-DVD collection often choose to obtain their backup from other sources. They have little control over the parameters used for encoding the source video. Many times, they end up with a complicated encode (say, a H.264 file with 16 reference frames). For some types of video (say, animation), it is arguable that encoding the source beyond the official Blu-Ray specs allows for better quality at a reduced file size. Is it possible for ATI's offerings to playback such files? No! The hardware might be capable (the extent is not fully known), but driver support is unfortunately lacking. A quick look at the post here (and the accompanying comments -- if you have time) indicates that NVidia and Intel support such complicated encodes without much tinkering from the consumer side.

For the HTPC enthusiast running Linux instead of Windows, even the usual acceleration is not available in a usable manner for the ATI or Intel GPU owners. NVidia goes out of its way to interact with the Linux users and actively supports open source projects (such as mplayer) to ensure that the capabilities of their GPUs can be exploited to the maximum possible extent by the end-users.

Winner : NVidia [ GeForce 210 / GeForce 220 ]

2. Audio Support:

It doesn't take long for the new HTPC enthusiast to realize that the video is only half the HD experience. A good solution is necessary for the audio component also. Analog audio outputs from on-board PC components are rarely trusted (mainly because of the quality of the DACs used). High end sound cards might help a little bit, but, when the whole HTPC picture is taken into consideration, it is often better (in my opinion) to invest in an AV receiver. I have already covered this in a blog post here. Let us cut this thread of discussion out and jump directly into how each of the three manufacturers fare in this regard.

a. ATI:

ATI has, for long, remained the leader as far as audio through GPUs is concerned. Right since their Radeon HD 3000 series, they have had an on-board audio processor. This implies that no SPDIF connections from the mobo to the GPU card are necessary, and the audio data is transferred through the PCI-E bus, processed and sent through the HDMI port. This makes installation of these GPU cards a cinch.

The Radeon HD 3000 series could support 2 channel LPCM over HDMI, DTS and Dolby (AC3) bitstreaming. This made sure that even a lowly 3000 series card could ensure a great audio experience. ATI continued its pioneer status with support for 8 channel LPCM over HDMI from the HD 4600 series onwards. With the recent release of the 5000 series, ATI one-upped the competition with support for bitstreaming of HD audio (Dolby TrueHD and DTS-HD MA). ATI needs to be commended for taking the first steps in bringing this hitherto locked down and costly feature within the reach of the masses (Not really cheap yet, but with the release of the HTPC oriented 5000 series in a few months, this should be in the hands of the cost-conscious consumer real soon!).

b. NVidia:

Audio is another department ( after marketing ;) ) where NVidia falters. Cards as recent as the GeForce 9000 series came with no on-board audio processor. Instead, the HDMI ports on these acted as dumb pass through for whatever came through the SPDIF connector from the motherboard. For people with mobos which had no (or already occupied) SPDIF connectors, installation of these cards were quite a hassle.

Recently, though, the situation has started to slightly turn for the better. Starting with the GeForce 210, NVidia places an on-board HD Audio controller. No more messing with internal SPDIF connectors. 8 channel LPCM, Dolby and DTS bitstreaming are also supported over HDMI. Basically, all the audio features which ATI had offered in the HD 4000 series from the 4600 onwards make its appearance on the NVidia cards.

NVidia still lags behind on HD audio bitstreaming, and there is currently no known plan from NVidia to support this feature in future cards.

c. Intel:

One of the most underplayed features of the Intel IGP is the fact that 8 channel LPCM, Dolby and DTS bitstreaming are supported right out of the box. HDMI capable X4500HD cards offer the same support for audio as the ATI 4600 and later cards in the ATI 4000 series or the newer NVidia GeForce 210 series and later. Intel also enjoys the advantage of the fact that most users can purchase them off the shelf and don't need to open up the PC case to install the cards.

Another advantage that Intel has over NVidia is the fact that their upcoming Clarkdale processor (which places the 45nm IGP with a 32nm CPU) has already been shown to support HD audio bitstreaming. This will turn out to be a very important distinguishing feature in the next year or two. NVidia will have a tough time explaining the advantage of their platforms such as Ion to HTPC enthusiasts if Intel is able to backup their Clarkdale offering with proper drivers (on the HD audio front).

Winner : ATI [ HD 4650 / 5000 series when the HTPC cards come along ]

3. Miscellaneous Aspects:

Some of the other aspects involved in choosing a graphics card for the HTPC include cost, reliability / power consumption, choice of operating system etc.

There is no doubt that when building a HTPC system from the ground up, the Intel IGPs (4500HD series and forthcoming offerings) tend to lower the cost of the system. Provided other factors are not of overriding significance, it might even be the best possible 'graphics card' (technically, these are integrated graphics processors and shouldn't be termed as graphics cards as such, since you can't go out and buy them stand-alone) investment from the price viewpoint for some HTPC enthusiasts.

Reliability and power consumption go hand-in-hand. It is well known that more the power consumption of a particular chip, the hotter it runs. This leads to lesser lifetime for the on-board components and results in lower reliability. A quick search on the Internet reveals that NVidia chips are notorious for their overheating / power management. While this doesn't automatically mean that the latest generation products also suffer the same issues, it does make one think twice before purchasing their cards.

If you are planning on running Linux on your HTPC, there is no option but to go the NVidia route. Fortunately, the support is excellent. Both ATI and Intel fail miserably on this front. If you are still running Windows XP (or plan to run only that in your new build), don't go the Intel route. You will hardly reap the benefits of the hardware.

Nowadays, both ATI and NVidia offer passively cooled cards which are quite powerful as far as HTPCs are concerned. So, there is hardly any differentiation in that aspect.


ATI's blatant disregard for decoding complicated H264 encodes, as well as the complete absence of support for the Linux HTPC scene and open source ecosystem leaves the well-educated consumer with little choice. They may earn a few brownie points with excellent audio support, but that is hardly satisfying for a well rounded HTPC experience.

Intel's lack of software support for Windows XP (still a leading O/S as far as installed consumer base is concerned) and Linux prevents it from being crowned as the manufacturer of the best HTPC graphics card.

As of December 2009, the best bang for the buck in the HTPC scene seems to be one of the NVidia GeForce 210 or 220 series cards.

This is a rapidly changing field and I am sure the crown will pass on from one manufacturer to the other in the coming months. Let us look forward to the efforts from the three giants to gain the confidence of the consumer. Till then, it is best to analyze the various factors and usage scenarios and make an informed purchase.

Note: If you are looking for a guide to build your new HTPC, do not forget to check out this very informative thread on AVS Forums. It discusses many other aspects of a HTPC build which are outside the scope of this post.

Disclosure: I am not a NVidia fanboy :) My HTPC uses a ATI 3450, while my personal laptop (which I use occasionally as a HTPC) uses a NVidia Quadro FX2700M. I recently set up HD playback on a laptop which had the Intel GMA 4500MHD. So, most of the observations made in the above post are based on personal experience.


About the Author:  Ganesh holds a Masters degree in Computer Engineering and is currently employed with Ambarella Corp in Santa Clara, CA as an ASIC verification / design engineer. When not thinking about video compression at work, he is busy at home putting products from other companies to task in his HTPC setup. He occasionally blogs his HTPC experiences and interacts with fellow enthusiasts on Twitter.