Introducing the AMD 890GX / SB850 Chipsets
Dedicated bandwidth for USB 3.0 ports means that
plugging something into a x4 PCI Express 2.0 expansion slot won't make your USB
3.0 ports suddenly stop working or operate at half their speed.
To put this in
perspective, USB 3.0's 4.8Gb/s theoretical bandwidth is enough to transfer a
25GB HD movie in about 70 seconds, something that would take 14 minutes on a USB
2.0 connection (or 9 and a half hours on USB 1.0). In the next year or two
expect to see USB 3.0's faster transfer used not only for high-speed storage
transfers but to also start connecting exotic devices like USB 3.0 HD displays
and external USB 3.0 graphics accelerators.
The NEC USB 3.0 controller should appear on most
motherboards that use the AMD 890GX chipset, although it's up to the motherboard
manufacturer to include and implement them.
While there have certainly been some tantalizing
improvements with the Radeon HD 4290's graphical abilities, the real excitement
comes from the new bandwidth added by the AMD SB850 southbridge chipset.
The role of the northbridge
and its control over PCI Express graphics, memory and the CPU has
changed dramatically in recent computer history. The southbridge has long been
passed over with only minor changes and upgrades. Since the southbridge controls
storage, USB, peripheral expansion, audio and networking, it's about time we saw
some upgrades on this front!
AMD's SB850 is the first southbridge
to have native SATA 6Gb/s connectivity, with full RAID support. With all
of the extra bandwidth that the SB850 southbridge controller is taking
on, AMD has also doubled the bus speed between it and the
890GX northbridge. This expanded northbridge-southbridge bus is called A-link Express III, and
this has 16Gb/s transfer rates.
AMD SB850 Southbridge with native 6Gb/s SATA III.
Certain board manufacturers have been able to 'bolt' SATA
6Gb/s controllers on Intel P55 platforms most notably, but benchmarks have
brought to light a number of compromises. SATA 6Gb/s connections need
a lot of system bandwidth, and to make room for them motherboard manufacturers
have re-routed PCI Express expansion lanes, resorted to bridge chips and even
sacrificed CrossFire/SLI graphics bandwidth in efforts to make SATA 6Gb/s work
in places it wasn't originally intended. And even then, SATA 6Gb/s support has been limited to two or four
ports at best, with limited RAID support.
The AMD SB850 controller has native SATA 6Gb/s support
built in, which theoretically means no compromises are necessary to enjoy faster
storage drives, especially those expensive Solid State Drives. A fast SSD in sequential read mode can saturate the
SATA 3Gb/s connections found on typical motherboards, so SATA 6Gb/s support
is more important than ever to avoid bottlenecks. Towards the end of 2010
new 25nm flash production techniques will make SSDs have larger capacities and
lower prices then ever before, so having the ability to connect SSDs at
full speed is good for future proofing your PC. Right now they are still
very much a luxury item, but new features like SATA 6Gb/s are always
about having the foresight to look forward 6 or 12 months.
The SB850 southbridge supports SATA 6Gb/s in
RAID 0, 1 5 and 10 modes, so you can even set up a massive array
of SSDs or conventional hard drives. SATA 6Gb/s connections are backwards
compatible with SATA 3Gb/s and SATA 1.5Gb/s hard drives, although to take full advantage
of the faster bus you need to match up a SATA 6Gb/s capable hard drive with a
SATA 6Gb/s connection to the motherboard.
Now, let's take a look at the layout of the ASUS
M4A89GTD PRO/USB3 motherboard...