M
uch hay has been made of the incred-
ible speed advantages PCI Express of-
fers over PCI. Beyond GPUs, however,
we haven’t found much worthy of occupying
those slots. Asus hopes to change that with its
Xonar D2X card—the fi rst soundcard we’ve
reviewed that makes use of the PCI Express
interface. The D2X is basically a PCI-E version
of the Xonar D2 (reviewed April 2008). In our
review of the Xonar D2 we lamented the card’s
lack of advanced EAX support—EAX 3 and
above are proprietary to X-Fi-chipped sound-
cards, making those cards the obvious choice
for gamers who want the best audio quality.
Or maybe not. With the Xonar D2X, Asus
has done an end run to get a level of advanced
EAX support in the card—but it’s not without
controversy. The D2X instructs games that it
has EAX 5, and the card’s drivers then shunt
the EAX calls into its own eff ects
engine. The results are far from
perfect. Using EAX compliance tools,
we found that the drivers didn’t support many
EAX functions, such as reverb and fi ltering.
Asus even admits to this. But the hack at least
gives the card access to some functions that
were previously locked up, such as support for
additional audio streams in Battlefi eld 2—one
of the handful of EAX games even available.
We’re more troubled by this card’s PCI Ex-
press support. Our D2X simply wouldn’t work
on two diff erent EVGA 680i SLI motherboards,
and users have reported issues with nForce
790i boards as well. Asus tells us the problems
are related to a BIOS issue that is being cor-
rected by board vendors. Nvidia confi rmed
that it is working on a BIOS update that should
be out by the time you read this. The D2X
worked fi ne on Intel P35, AMD 790FX, and
MSI nForce 750i boards.
The Xonar D2X uses the same audio co-
decs and off ers the same I/O ports and Dolby
Digital Live support as the D2. The D2X, how-
ever, requires a fl oppy connector for power.
In game frame rates, the PCI Xonar D2
was slightly faster than the D2X. We surmise
this is due to superior drivers for the D2 or the
PCI-to-PCI-E bridge chip on the D2X. Either
way, the diff erences are minimal, and frankly,
frame rates should no longer be the primary
factor in soundcard decisions. Far more impor-
tant is audio quality and gaming API support.
In these areas, the Xonar D2X does well. The
audio quality, rated at 118dB, is quite good,
with no transient audio ghosts. The AuzentechX-Fi Prelude (reviewed April 2008) edges the
D2X in our 24-bit/96KHz audio-fi le listening
test, but honestly, both cards sound great and
far exceed onboard audio.
So what would we buy? It depends. The
advanced EAX in the Xonar is fl awed, but it
sorta works. If you want a full EAX 5 card,
you have to go X-Fi. But that limits you to
PCI, as the PCI-E version of the X-Fi lacks ad-
vanced EAX support. That makes the Xonar
D2X the most feature-rich PCI-E card today,
and that’s not a bad place to be—even if the
EAX is faked. – GORDON M A H U N G78 |MAMAMAXIMXIMXIMXIMUUUUMMPPPCC| JUL 08 08 | http://www.maximumpc.com
IN THE LAB^
REVIEWS OF THE LATEST HARDWARE AND SOFTWAREAsus Xonar D2X
Got an empty PCI-E slot? This soundcard wants to fi ll it
+ -
VERDICT$200, http://www.asus.com8
Initially spotty PCI-E
support that must
be fixed with a BIOS
update.The EAX 5 hack is
commendable and
the card’s LED lights
add flash.PICCOLOASUS XONAR D2XPAN FLUTEAsus’s Xonar D2X could be the most powerful
PCI-E gaming soundcard available today.