Wednesday, May 19, 2010

HTPC Build Part 4 - Testing an Intel-based HTPC

This is the forth in a series of posts I’m writing about an HTPC (Home Theatre PC) build that I recently completed.  To see a list of all posts in this series, click here.

Before finalizing a parts list and placing an order for the parts for my new HTPC build, I was fortunate to be able to gain access to a "test machine": A newly-built, working HTPC that my friend Dave was kind enough to let me borrow for a few days.  Specs on this machine:

CPU Intel Core 2 Quad
Motherboard Intel BOXDG43GT LGA 775
Memory 2 GB Kingston DDR2-800
Onboard Video Intel GMA X4500 with HDMI
Add-on Video Card (None)
Operating System Windows 7 Home Premium 64-bit

I brought the Intel HTPC home and hooked it up to my TV, a Philips 3000 series LCD HDTV.  As with the old 2004 PC that I tested using as an HTPC, the Intel test PC had some pros and cons.  Pros first:

  • The PC ran very silently -- there was no noticeable fan noise at all while the machine was on.
  • It was easy to connect the PC to the TV via the built-in HDMI port, and both video and sound output were transmitted from the PC to the TV via a single HDMI cable.
  • No problems at all with HD video playback.

I ran into a significant problem, though: When rendering video output at the TV's native resolution (1920x1080), the rendered screen image was "too big" for the TV.  The edges of the Windows desktop, including the taskbar and Start button, were off the screen.  Those elements were still present -- I could move the mouse off the screen to where the Start button should be located, click, and (partially) see the Start menu appear -- I just couldn't see them.

After spending a while trying to research this problem online but running into problems getting quality Google search results when trying to search using terms like "htpc tv image too large" or "tv display edges not visible" (and multiple other variants), I finally came across an article where I learned that there is a specific word for this phenomenon: Overscan

Now, searching with search terms including the word "overscan," the quality of search results I was able to find markedly improved.  However, I was still unable to solve the problem; in several hours of trying, I was unable to correct for the overscan either from the PC side, or from the TV side.

Most PC monitors include geometry controls that allow the screen image size, but there were no such controls available in the my TV's built in software menu.  In further poking around online, I found an avsforum.com thread that described how to access a "secret" admin/service menu where additional TV controls could be accessed; I actually got this to work on my TV and accessed the TV menu (after bypassing a warning about possibly voiding my warranty -- the TV is out of warranty anyway), but on my TV, there were no geometry controls in the admin menu, either.  Finally, I tried to do a firmware update for the TV's software to see if a later version would have the geometry controls I was looking for, but the TV reported that it was already running the latest version of the software when I tried to apply the update via the TV's built-in USB port.

I also investigated correcting the overscan on the PC end of things.  The Intel video card comes with software that allows a lower screen resolution to be sent to the monitor/TV to correct for overscan; however, whenever I tried to apply a "non-standard" lower resolution, the Intel software itself complained that the target resolution was not supported by my display.  Setting the screen to the next-lowest standard widescreen resolution (1680x1050) resulted in wide areas of black around all four edges of the display, so that wasn't a good solution either.  I tried updating to the latest version of the Intel video driver and video software utility package, but that didn't help either.

So, I was left with the question of whether the overscan problem would be a deal-breaker for my intended uses of the HTPC.  My goals for the HTPC were as follows:

Primary goal:

  • Be able to automatically record and playback HDTV program broadcasts.  (Tivo-like DVR functionality)

Secondary goals:

  • Be able to use the HTPC as a secondary home PC, i.e. to do things like browse the Web, check email, and view photos and videos.
  • Be able to play DVD movies (and later, Blu-Ray movies, once the price of Blu-Ray optical drives drops).
  • Be able to play old NES, SNES, and N64 games that I own the cartridges for (via emulation).
  • Be able to play newer games while sitting on the couch and using my XBox 360 controller for PC -- have the HTPC act as a "poor man's XBox 360." (Ironically, though, an actual XBox 360 now retails for significantly less than my overall budget for the HTPC!)

With respect to the primary goal of playing back HDTV content, I needed to be able to use the Windows Media Center (WMC) interface in order to accomplish this.  With the overscan problem, several of the key UI elements of Windows Media Center appeared off the screen.  However, I found a post on Aaron Stebner's WebLog detailing a series of registry keys that can control advanced options in Windows Media Center.  Using these registry tweaks, I was able to get WMC to "pull in" from the screen edges its various UI elements, such that everything was visible on my screen, even with the overscan.  Pretty cool.

However, I had no such luck with applications outside of Windows Media Center.  With the Windows taskbar, the Start button, and the edges of the Windows desktop being out of view, using the HTPC as a regular Windows PC wasn't a very nice experience. 

I also encountered one other problem: On the Windows desktop, thin black lines (such as "divider lines" in various applications) sometimes rendered on screen with quite a bit of "flicker".  This didn't make the display unusable, but it was pretty annoying to look at.

Between the overscan problem and the "flicker" problem, I made a decision not to go with an onboard Intel video card for my final HTPC build.  Having had good experiences with ATI video cards in the past, I decided I would instead go with an AMD-based build including an onboard ATI video card. (The processor company AMD acquired the video card company ATI back in 2006, so now AMD is presumably using the solid ATI technology in its onboard video cards.)

I did also do some testing with the Intel machine with my secondary goals in mind.  Old NES and SNES games ran just fine on the PC via emulation; I was worried there might be some lag time between controller button presses and the responsiveness of the games, but there was no noticeable lag at all, and the games I tested were very playable. 

WoW_OverscanCrop2 I also tested a couple of newer games: World of Warcraft, and Batman Arkham Asylum.  Warcraft (being a 5-year-old game at this point) ran quite acceptably when configured to use lower-end video settings.  However, the game was affected by the overscan issue, making the action button bar at the bottom of the game window partially invisible, resulting in the game being not very playable, at least in full-screen mode.  (The screen capture at right approximates what I was seeing on my HDTV in terms of the game image being clipped.)

Batman Arkham Asylum, a newer game, ran on the PC, but the game ran very slowly, even on minimum video settings.  Although the game ran, it wasn't really playable.  Somewhat interestingly, rather than drop frames and run at normal speed but with a poor framerate, the game just slowed down the overall gameplay to match the throughput that the video card was able to produce -- the end result was although the display was smooth, the game just ran at about 50% of normal speed (so it took Batman an unusually long time to walk from place to place, etc.). 

The poor performance of the Batman game was actually in line with my expectations: I didn't expect the onboard video card to be performant for high-end gaming.  My plan at this point is to run with only onboard video for the time being (sacrificing the goal of being able to use the HTPC as a "poor man's XBox 360"); at some point in the future, I'll purchase an add-on video card for the machine (or maybe, I'll purchase a new video card for my primary desktop PC, and do a hand-me-down of that PC's old video card to the HTPC).

The next post in this series will (finally!) cover my final HTPC parts list, and my experiences with the completed build.

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