ASRock VisionX 471D Review - Evolutionary Upgrades for a Powerful mini-PC

HTPC Credentials

The VisionX 471D has a much better acoustic profile compared to the BRIX Pro and even the ZBOX EI750 (thanks to the larger chassis, which, in turn, allows for a better thermal solution). Subjectively speaking, I found it to be ideal for a gaming HTPC, but it is definitely no substitute for an actively cooled NUC or passive HTPC. On the performance side, the AMD R9 270MX should be capable enough for madVR, but we will try to identify the limits in this section. Prior to tackling that, we have two HTPC aspects to explore.

Refresh Rate Accurancy

AMD and NVIDIA have historically been able to provide fine-grained control over display refresh rates. The default rates are also quite accurate. Intel used to have an issue with 23 Hz (23.976 Hz, to be more accurate) support, but that was resolved with the introduction of Haswell. As expected, the ASRock VisionX 471D has no trouble with refreshing the display appropriately in the 23 Hz setting. The accuracy is not as much as what we could get with Haswell and Bay Trail-based systems.

The gallery below presents some of the other refresh rates that we tested out. The first statistic in madVR's OSD indicates the display refresh rate.

Network Streaming Efficiency

Evaluation of OTT playback efficiency was done by playing back our standard YouTube test stream and five minutes from our standard Netflix test title. Using HTML5, the YouTube stream plays back a 720p encoding, while Adobe Flash delivers a 1080p stream. Note that only NVIDIA exposes GPU and VPU loads separately. Both Intel and AMD bundle the decoder load along with the GPU load. The following two graphs show the power consumption at the wall for playback of the HTML5 stream and the Adobe Flash stream in Mozilla Firefox (v 35.0). The Flash plugin version used for benchmarking was 16.0.0.257. GPU load was around 7.06% for the HTML5 stream and 4.5% for the Flash stream.

Netflix streaming evaluation was done using the Windows 8.1 Netflix app. Manual stream selection is available (Ctrl-Alt-Shift-S) and debug information / statistics can also be viewed (Ctrl-Alt-Shift-D). Statistics collected for the YouTube streaming experiment were also collected here. GPU load in the steady state for the Netflix streaming case was 1.85%.

Decoding and Rendering Benchmarks

One of the major 'HTPC' drawbacks we had reported in our VisionX 420D review was the absence of hardware decode acceleration for 4K H.264 clips. Recently, ASRock released a new BIOS version (v 2.0), which added a new option to enable multiple monitors with the Intel iGPU. Intel's Quick Sync decoder is one of the best in the business, and, with Haswell iGPUs, it can decode 4K videos without any problems. We enabled this BIOS option, configured a new monitor (with an extended desktop) using the Intel HD Graphics GPU to drive it even in the absence of a physical display. This allows for Intel Quick Sync to be used with LAV Video Decoder in MPC-HC.

In order to evaluate local file playback, we concentrate on EVR-CP and madVR. We already know that EVR works quite well even with the Intel IGP for our test streams. Under madVR, we used the default settings initially. We also put together a 'madVR stress configuration' with the upscaling algorithms set to Jinc 3-tap with anti-ringing activated and the downscaling algorithm set to Lanczos 3-tap, again with anti-ringing activated. The decoder used was LAV Filters bundled with MPC-HC v1.7.7

The results present no marked departure from what we observed in the VisionX 420D review, despite decoding duties being take up by the Intel Quick Sync engine. 4Kp30 with stressful madVR processing for display on to a 1080p screen was not a pleasant exercise (too many dropped frames). One other aspect that helped in smooth playback of other streams was the setting of different internal queue sizes to the maximum possible values in the madVR settings.