People in the West are always getting ready to live - Chinese proverb
WITH NVIDIA AND ATI firmly controlling the world of card graphics card design, coming up with unique flavours isn't an easy job. You might double the memory or replace the cooler, but what about going further than that?
Asus has done exactly that, by creating the first cards with much more flexible voltage and frequency control for superb overclocking. Something that required a fine soldering iron and lots of arcane knowledge until now.
The most powerful Matrix series currently in production, – the HD4870 – adds this new power and speed control system, as well as two independently-controlled fast fans taking care of not just the GPU, but also RAM and power areas, to the reference. The resulting product not only has better looks than the ATI reference card, but also aims to provide the best combo of properly accelerated 3-D gaming modes (higher voltage for stability combined with good cooling) and silent, low power, low speed 2-D mode as well. After all, what's the point of burning extra watts when you're pootling about on the interwibble?

Asus went all the way, controlling both the GPU and memory voltage and speeds, as well as having its own ASIC reporting back the actual GPU load as well as temperature, and adjusting the speed in real time. Not to mention a 4+2 phase power supply on top of better capacitors and MOSFETs. Wow! We had to try this.
The card installation, besides the usual Catalyst, adds the Asus Tracker utility. Now you can choose from five operating modes, including nearly completely silent Quiet mode for 2-D work at lower power cost, and Gaming mode for top performance. If not happy making settings manually, you can use optimised presets to let the card make the choices for you.
The standard 770 MHz GPU clock and 3.68 GHz GDDR5 speed are no slouches anyway, but can be sped up further.
First thing; the card was slightly quieter than the Sapphire, and substantially quieter than the reference. I was interested on the impact of high GPU and memory speed but only standard RAM capacity of Asus Matrix vs double the memory on the Sapphire, and of course slowest clocks and standard memory on the reference.
Take a look:

In summary: a great card, among the most unique around - pity there isn't a 1 GB version. I hope Asus does a HD4890X2 version of this, maybe with three fans and still fitting in two slots. Now, that would be a stunner!
The Good
Silent, fast performance
The Bad
No 1GB version
The Ugly
Single GPU... for now
Bartender's Verdict
9 out of 10

This card is far noisier than the reference card. Its cooler and very tweakable, but at the expense of noise.
Its rather annoying when idle as the fan spins up, and down, up and down - constantly.
http://www.silentpcreview.com/asus-hd4870-matrix
Andy