Discrete HTPC GPU Shootout
by Ganesh T S on June 12, 2011 10:30 PM EST
One of the drawbacks of the GPUs built into the Clarkdale/Arrandales CPUs and the Sandy Bridge CPUs was the lack of 23.976 Hz for matching the source frame rate of many videos. Combined with the lack of reliable support for open source software, this has often pushed users to opt for a discrete HTPC GPU.
Ideally, a GPU should be capable of the following refresh rates at the minimum:
- 23.976 Hz
- 24 Hz
- 25 Hz
- 29.97 Hz
- 30 Hz
- 50 Hz
- 59.94 Hz
- 60 Hz
Some users demand integral multiples of 23.976 / 24 Hz because they result in a smoother desktop experience, while also making sure that the source and display refresh rates are still matched without repeated or dropped frames.
However, being in the US (NTSC land), we are looking at the minimum necessary subset here, namely, support for the following:
- 23.976 Hz for 23.976 fps source material
- 24 Hz for 24 fps source material
- 59.94 Hz for 59.94 fps source material
We have observed that the refresh rate is heavily dependent on the AV components in the setup (a card which provided perfect 23.976 Hz in my setup performed quite differently in another). In order to keep the conditions same for all the contenders, the custom refresh rates were tested with the HDMI output of the card connected to an Onkyo TX-SR606 and then onto a Toshiba Regza 37" 1080p TV. The Toshiba TV model is indeed capable of displaying 24p material.
GT 430:
The NVIDIA Control Panel provided a 23 Hz option by default when connected in the test setup. This is obviously coming from the EDID information. Setting the refresh rate to 23 Hz and playing back a 23.976 fps video resulted in the following:
Note that the playback frame rate locks on to 23.971 fps, and the display refresh rate also loosely locks on to 23.971 Hz. Unfortunately, this is only slightly better than the 24 Hz lock that Intel provides for the 23 Hz setting. With this, one can expect a dropped frame every 200 seconds.
Fortunately, NVIDIA provides us with a way to create custom resolutions using the NVIDIA Control Panel, as in the gallery below.
The display mode refresh rate should be set to 23 Hz, and the Timing parameters need to be tweaked manually (altering the refresh rate to change the pixel clock). This is more of a trial and error process (setting the refresh rate to 23.976 as in the gallery below didn't necessarily deliver the 23.976 frame lock and refresh rate during media playback). With a custom resolution setup, we are able to get the playback frame rate to lock at 23.976.
The display refresh rate oscillates a little around this value, but, in all probability, averages out over time. We do not see any dropped or repeated frames.
Moving on to the 24 Hz setting (needed for 24 fps files, common in a lot of European Blu-rays), we find that it works without the need for much tweaking.
Playback locks at 24 fps, and the refresh rate oscillates around this value with very little deviation.
The default NTSC refresh rate (59.94 Hz) works in a manner similar to the 24 Hz setting, as is evident in the gallery below.
MSI GT 520:
With respect to custom refresh rates, the GT 520 is very similar to the GT 430. The 23 Hz setting, at default, had the same issues as the GT 430, but nothing that a little tweaking didn't fix. The gallery below shows the behavior with the default 23 Hz setting:
After setting up a custom resolution, we get the following:
The 24 Hz setting, at default, showed a slight issue with the playback frame rate locking at 24.001 Hz. This would imply a repeated frame every 1000 seconds (~17 minutes).
This can probably be fixed by altering the timing parameters for the 24 Hz setting, but we didn't take that trouble.
Setting up NTSC refresh rates with the 59 Hz native setting gave us the following results, similar to the issue we had with 24 Hz setting.
DDR3 and GDDR5 based 6450 :
We didn't find any difference between the two versions of the 6450 that we tested with respect to refresh rate handling. In this section, we will present screenshots from the GDDR5 based 6450.
Catalyst Control Center automatically enables the 23 and 24 Hz settings in the drop down box for refresh rates by recognizing the EDID information. How well do these settings work? A look at the gallery below shows that the behavior is better than Intel's and NVIDIA's native offerings. However, there is still the issue that the play back frame rate locks to 23.977 fps / 24.001 fps. The refresh rate is not exactly 23.977 either, but mostly below that. All in all, this is not the ideal 23.976 Hz, but something that the 'set-it-and-forget-it' crowd might be OK with.
We didn't get a chance to test the 59.94 Hz settings for videos, because the 6450s' way of playing back 1080p60 videos was to present a slideshow. A brief look at the gallery below reveals the issue:
There is a little bit more coverage about this in the 'ESVP on the 6450s' section.
Sapphire 6570:
While the 6450 was only slightly off from the required 23.976 and 24 Hz settings, the Sapphire 6570 took a little more liberty. 23 Hz gave us 23.978 Hz and 24 Hz gave us 24.002 Hz, resulting in repeated frames every 500 seconds.
The 59 Hz setting for the 6570 gave us 59.946 instead of 59.94, which eventually results in a repeated frame every 167 seconds (~3 minutes).
The takeaway from this section is that none of the GPUs can claim to do fully perfect 23.976 Hz refresh rates. With luck, the ATI card in a particular setup may be able to provide the perfect refresh rate. After all, they came very close to the required settings in our testbed. The NVIDIA cards, at default, are probably going to be always off. However, for the advanced users, there are some avenues available to obtain the required display refresh rate. Unfortunately, there is no way I am aware of to feed custom refresh rates in the Catalyst Control Center.
Before I started the review, it was my opinion that AMD is much better at native refresh rates compared to NVIDIA. After putting the various cards through the paces, I am forced to reconsider. AMD may work well for the average HTPC user. For the more demanding ones, it looks like NVIDIA is the winner in this area because of the ability to create custom resolutions.
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casteve - Monday, June 13, 2011 - link
I hope to see a review of the HD 6670, now that (at least) Sapphire has released a passive version.Drae - Monday, June 13, 2011 - link
... it'd be nice to see more use of Linux please. I realise there are a lack of "testing" and "evaluation" tools under Linux but that shouldn't prevent the testing of basic media needs. What's this about no bit streaming support under Linux? Boxee would disagree - as would:http://phoronix.com/forums/showthread.php?27348-Tr...
along with XBMC's audioengine (involving work by the guy in the above link). Maybe Windows 8 will sort out the mess that is WMC and all the messing (or bypassing with MPC-HC) that is required to get it working solidly. But right now if you want something that approaches a plug and play media experience XBMC (and its off-spring Openelec) under Linux is a lot closer than Windows. Equally the more coverage such solutions get the more likely greater time will be spent fixing the remaining issues under the Linux OS - hello there Intel and AMD.
Finally there is a great move now - go look at AVS' fora for examples - away from large media center pc's to small, quiet (silent) systems. These don't require 300W or 500W power supplies and huge cases with twelve fans and fifty million led's. They are ITX based systems sitting in small ITX sized boxes running 65/80/90/120W PicoPSU's with much greater efficiency and thus lower power use/running costs/silence. Placing these discrete cards in such systems would be a nice test of these picopsu units - given the apparently low power draw shown in the articles (something I'm very interested in seeing right now given the poor support of Linux by Intel on Sandybridge - the GT430 would be a good interim solution for me).
TLDR: Please don't limit yourselves to Windows testing and ATX/mATX sized systems when writing HTPC articles
ganeshts - Monday, June 13, 2011 - link
Drae, Thanks for the info and the link.The issue with Linux HTPCs is the fact that there is a semblance of support from only NVIDIA.
Don't get me wrong! I am a huge Linux fan, and always prefer free / open-source software. But, from a video perspective, is there a multi-GPU platform similar to DXVA ? Every vendor has their own flavour (NVIDIA - VDPAU / Intel - VA-API / AMD - XvBA). From the audio side, it looks like the link you mention is the only avenue available for bitstreaming, and that too for NVIDIA GPUs only. I will keep close tabs on what is happening in this area, and when the time is right, I will definitely post a piece on Linux HTPCs, considering one card from each of the vendors.
cjs150 - Tuesday, June 14, 2011 - link
As always it depends on what you want from an HTPC. For me I want to play Blu rays, stream HD movies from file server, watch and record TV and do some web browsing but in total silence (or as close to as possible).For me ITX systems are the way to go using a 150W PICO-pSU but critical is that they have to work with appropriate IR remote (Logitech DiNovo looks interesting)
I am happy to use Linux or Windows but it just has to work
alfredska - Monday, June 13, 2011 - link
This kind of quality review is what made AnandTech a name to remember early on. I'm glad to see such thoroughness and well thought out presentation of information. Looking forward to more reviews by Ganesh.UrQuan3 - Wednesday, June 15, 2011 - link
Agreed, this is an excelent article. I tried cross referencing to the "Zotec Zbox" article from the 9th (I own an E-350) and the earlier benchmarking was useless. I already know the E-350 won't do full processing, but I wanted to know where it sits compared to these platforms that pull 3-10 times the power.Think a 'software mode' might have been useful? An i5 could have done a fair amount of this processing without a hardware assist, saving the 70watts the cards were pulling and avoiding some of the integrated's compatability issues.
Shadowmaster625 - Monday, June 13, 2011 - link
I dont get the video card focus in the realm of HTPC. It seems that software is a far more important piece of the picture than a video card. Windows media center and XBMC both work like crap, and/or are unacceptably slow and clunky when it comes to browsing media. I do NOT tolerate that kind of lag, especially on a 3 ghz quadcore with an ssd/hdd drive setup. I dont expect miracles when trying to browse through a gigabyte of media, but still it should be faster. And then there's audio sync problems that like to appear out of nowhere. But you'd never know any of these problems exist from reading these articles. Shrug.I have found that VLC media player and windows explorer are the most reliable combination. But using windows explorer on an htpc is ugly and painful.
JasonInofuentes - Tuesday, June 14, 2011 - link
I think part of the problem is the degree to which there's news. A thorough review of Media Center might be warranted, the next time it changes, but was pretty thoroughly covered here (http://www.anandtech.com/show/2864/) and here (http://www.anandtech.com/show/2760). XBMC has a more frequent update cycle than Windows, and there's obviously interest so this might be an idea to explore further.As far as the difficulties with each of these platforms, a Z68 platform and SRT might be the solution here. So the size of the files is not really the problem, it's that when you browse to a folder the user wants to be able to scroll around the list or grid and have all of the information pertinent to those files readily available. You don't want to scroll over to a file in your West Wing Season 5 folder and wait for the Title to load so you know whether it's the episode you were looking for, you want that information to be up the instant you scroll to it, or even better for it to be glanceable before you even start scrolling. In order to achieve this the OS's load all of the information for all of the files in the folder. So if you have a few dozen files in a folder that's the metadata for each files, the thumbnail preview and then the usual file system queries the OS would do anytime it accesses the drive. That can add up to a lot of small reads, and that leads to that big stall as you scoot around your media.
Now, the throw money at it solution is move to ALL SSD storage. But I've got 4TB of media and don't have that kind of money to throw at the problem. SRT should help though. If I recall, the metadata and thumbnail files are stored locally in the folder with the files, but since SRT caches the frequently accessed files, then for a system used exclusively for media the only thing that should populate the SSD cache is going to be these small reads that otherwise slow down your system.
I am suddenly overwhelmed with an urge to get my hands on a Z68 to try this out! And you are quite right that VLC and Windows Explorer are the most reliable programs for browsing and playing back media, but the price you pay for pretty is often performance.
vailr - Monday, June 13, 2011 - link
As an exercise in "possibility thinking", I'd be interested in a sub-category of a complete "solar powered" desktop-format PC review. Designed (theoretically) for someone living in a remote area, off the electrical grid, yet still having internet via satellite, cell phone signal, or otherwise connected. Designed for ultra low power consumption, mostly dependent on solar and/or wind power produced on site. Yet maximal possible performance (under such power restrictions) for either: generic gaming desktop PC, and also for a HTPC. Using SSD's and/or laptop HD's for storage, and with an energy sipping CPU (dual-core Atom vs. Intel i330, for example), combined with either: on-CPU chip video or a "PCIe bus only" powered video card, and yet somewhat viable as a gaming PC or as a HTPC.Maybe even qualify for an article in Home Power magazine? http://homepower.com
Penti - Monday, June 13, 2011 - link
Why? Running a 100 W PC of batteries is pretty pointless.Just install FTTH and a powerline if you like to game or do other intensive tasks needing GPU-power, fast cpus or ridiculous amounts of memory (workstation type stuff). It would be the most efficient solution any way. You don't even need any power for any modems. You certainly can run a PC of battery power off grid, but why destroy your work with that. It would be hard to store much electrical power.
Otherwise you would pretty much had to get by with a low-powered laptop. No monitor.
Do the unabomber type guys need any gaming? If so they need to install a good damn power line or at least a diesel-generator. They don't have the money and skills to build energy storage and buy panels thats enough to power a modern home any way.