A gaming rig is nothing without some high quality audio blaring from the speakers.  I mean, just think how boring the original DOOM would have been if you hadn't heard those Imps snarling off in the distance?  We put the M-Audio Revolution into one of our newest systems to view its performance versus a comparable card, the Audigy 2.

The Hot Hardware Test System Adding top-notch audio to a top-of-the-line system

Chaintech APOGEE 9PJL (I865PE)
Intel Pentium 2.40C (800MHz FSB)
512MB (2x 256MB) GEIL DDR433 SDRAM
Tyan Tachyon G9500 Pro (Radeon 9500 Pro)
M-Audio Revolution 7.1

Creative Labs Sound Blaster Audigy 2
Western Digital 20GB ATA100 7200rpm Hard Drive
Pioneer 16x DVD DVD-105
Windows XP Professional SP1
Logitech Z640 5.1 Surround Sound Speakers
 

Performance Benchmarks Putting the card through the wringer

Audio WinBench 99:

Audio WinBench 99 measures the performance of a PC's audio subsystem, which includes the driver, the processor, the DirectSound and DirectSound 3D software, and the speakers.  We ran through a series of playback tests that vary the sampling rates and bit rate, and then report the CPU Utilization percentage.  Of these 8 tests, we chose two of the results that were representative of DirectSound and DirectSound3D performance.

The Revolution 7.1 used many more CPU cycles, in some cases more than double, than the Audigy 2 in head-to-head testing.  This is due mostly to the fact that the Envy 24HT does not provide anything in the way of DirectSound acceleration.  In other words, it relies upon the CPU to process these sound streams.  We will have to check in later to see how this affects gaming.

3DMark03:

It might seem odd to find Futuremark's 3DMark03 in an audio card review, but we found the sound tests portion to be of some interest.  Much like Audio WinBench 99, 3DMark03 plays the "Wings of Fury" scenario three times, first with 0 sounds, then 24, and 60 sounds.  After which, the frame rate is shown for each of these tests.

Without any sounds, we achieved the same number of frames per second, which at the very least proves that nothing else may be affecting these tests.  Using only 24 sounds, we can see a difference of about 12 frames between the two cards.  The Revolution 7.1 dropped almost 20 frames, close to 33% down from the original score.  Only the Audigy 2 was able to complete the last test, as the Revolution 7.1 only supports up to 33 3D channels when set to Sensaura/Game Mode.

Comanche 4 Demo:

To supplement the 3DMark03 benchmark, we fired up Novalogic's Comanche 4 Demo, which is heavily dependent on CPU and Memory bandwidth.  If there is any kind of processing of audio by the CPU, we should surely seem a drop-off in the frame rate here as well...

To no surprise, we saw a decrease in frame rates when audio was enabled in this benchmark.  Using an Audigy 2, we saw only a minor hit in performance.  For the Revolution, we tried running two tests, once with no surround sound processing, and the other with Sensaura/Game mode enabled.  With no 3D sound enabled, there was less of a difference, about 3 1/2  frames off of the "no audio" frame rate.  Once game mode was enabled, however, another 2 1/2 frames were lost, or 6 fps altogether.  This equated to a 12% loss in performance. 

Audio Quality and Conclusions