Hiper Media Center Barebones PC

POWER / ENERGY EFFICIENCY

The system drew more power than expected in every activity, considerably higher than the somewhat similar system we assembled around the Albatron KI690-AM2 board reviewed a couple of weeks ago. That system utilized a standard 65W TDP A64-3800+ X2 processor, but a well known exceptionally high efficiency power supply was employed, and there were no extras such as WiFi or VFL to demand any extra power. Still the Albatron system drew just half the power at idle, and 20W less at full load; lower efficiency in the Hiper's power supply is probably the main source of the difference.

Engaging Cool 'n' Quiet had the expected positive effect of dropping overall power at idle and low power loads by as much as 8~10W, which is welcome for both energy efficiency and reduced heat. Active power factor correction must be employed in the PSU, as the PF measured 0.98~0.99 at most power levels.

PICOPSU SUBSTITUTE

The small size of this system and the relatively noisy power supply invited a drop-in substitution with a PicoPSU. The PicoPSU, which we reviewed some time ago, is a tiny ATX-socket sized DC/DC converter which passes 12V current from an external AC/DC power brick, and also delivers the necessary +5V, +3.3, +5Vsb and -12V. It has extremely high efficiency, and has the benefit of allowing the main heat source in the PSU (the AC/DC conversion) to be placed outside the computer.

The stock PSU was left in place, and its power connections were changed with those from the PicoPSU. A couple of adapters had to be used, as the PicoPSU comes with a minimum number of outputs, which caused a bit of a wiring mess... but this was just an experiment anyway. A 120W rated 12VDC AC/DC power brick was used.

PicoPSU plugged into the ATX socket, jammed up against the front panel memory card reader PCB.

The power brick and the PicoPSU are highlighted in this photo.

The results were quite dramatic.

Hiper Media Center PC w/ Windows XP: Stock PSU vs. PicoPSU
Activity	AC Power		SPL* dBA@1m
	Stock PSU	PicoPSU
Off	2W	3W	N/A
Sleep (S3)	6W	6W	N/A
Idle	69W	54W	23 dBA
Idle w/ Cool 'n' Quiet	64W	49W	23 dBA
Rush Hour 3 video	80~84W	77~80W	23 dBA
Coral Reef Adventure video	81~84W	78~82W	23 dBA
CPUBurn	105W	86W	23 dBA
*SPL is the sound pressure level, measured in "A" weighted decibels with a high sensitivity B&K sound level meter at a distance of one meter.

There really isn't much more to say; the table above tells it all. The PicoPSU turns a moderately noisy system into one that's truly quiet and highly efficient. It had no problem powering the system through each and every activity. There's no reason for Hiper not to go the route of the external power brick, a route which has been taken successfully by Shuttle with several of their SFF systems. Shuttle's SD11G5 Pentium-M PC and the earlier 478-socket Zen XPC ST62K had fanless 220W and 180W 12V AC/DC power bricks which completely eliminated PSU noise and heat from these PCs.

NOISE RECORDINGS IN MP3 FORMAT

Each of these recording starts with six seconds of "silence" to let you hear the ambient sound of the room, followed by 10 seconds of the product's noise.

• Hiper HMC-2K53A-H2 test system at idle - 31 dBA@1m
• Hiper HMC-2K53A-H2 test system at full load - 35 dBA @1m
• Hiper HMC-2K53A-H2 test system with PicoPSU - 23 dBA @1m

HOW TO LISTEN & COMPARE These recordings were made with a high resolution, studio quality, digital recording system, then converted to LAME 128kbps encoded MP3s. We've listened long and hard to ensure there is no audible degradation from the original WAV files to these MP3s. They represent a quick snapshot of what we heard during the review. The microphone was one meter away from the product. These recordings are intended to let you hear how the reviewed item sounds in actual use — one meter is a reasonable typical distance between a computer or computer component and your ear. The recording contains stretches of ambient noise that you can use to judge the relative loudness of the subject. For best results, set your volume control so that the ambient noise is just barely audible. Be aware that very quiet subjects may not be audible — if we couldn't hear it from one meter, chances are we couldn't record it either! More details about how we make these recordings can be found in our short article: Audio Recording Methods Revised.