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ATI Chimes In |
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No bridge is better than one |
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ATI is quick
to argue against NVIDIA's approach in adopting PCI
Express. According to representatives at ATI, its
native implementation of PCI Express enables full
performance provided by the interface, including all
bandwidth and power management features. ATI also
claims its design is more economical, as individual
bridge chips are expected to add somewhere around $8 to
each of NVIDIA's boards. NVIDIA counters that its
pricing is already set, and there won't be a pricing
change in light of the bridge chip.
There are a
few other reason ATI cites for not using the bridge
chip, the most prevalent of which is a possibility of
higher latency caused by translating AGP to PCI Express
and vice versa. The ATI solution is also "less risky"
according to an ATI presentation, purportedly because
the bridge chip introduces another potential point of
failure. That one's a bit tougher to argue since
ATI has to pull apart its GPU to add PCI Express
support, anyway.
ATI's bridgeless
solution.
In the bottom illustration, ATI is
making the point that adding a bridge introduces one
more potential failure point.
When asked
about the procedure for adding PCI Express to existing
GPUs, ATI was adamant that the cards introduced on
current architectures aren't simply patched-up versions
of today's processors, suggesting the possibility of
other minor changes once ATI announces its complete
lineup.
Considering
ATI's real-time hi-def video editing demonstration, it
seems to be on track to deliver once complementary
chipsets are available.
What, then,
are the real implications of PCI Express? To be
quite frank, it's still too early to tell. After
all, neither NVIDIA nor ATI have cards available, though
the former has already announced an entire product
lineup and the latter has already demonstrated real-time
HD video editing on a PCI Express platform. As
with each of the past revisions to AGP, it will
undoubtedly take quite a while for software to begin
exploiting the bandwidth advantages of PCI Express.
Then again, representatives at ATI claim that the video
editing software they demonstrated will be available
sooner than one might expect.
At some
point, the lofty bandwidth numbers that PCI Express
boasts will probably be of utmost significance.
Right now, however, there is little in the way of
software capable of taxing AGP 8x, much less its faster
successor. We'll certainly have to wait until
hardware materializes, but even then, interface
considerations will probably play a secondhand role in
determining the performance of next-generation's round
of high-end graphics cards.
The more
important market for PCI Express is mobile graphics,
where low power, small size, and high performance are
all prized attributes. The ability to turn lanes
on and off according to system needs should prove useful
in stretching battery power, and mobile PCI Express
graphics boards should be significantly smaller than
their AGP counterparts. In recent discussions with
NVIDIA and ATI, both companies have confirmed with
confidence that PCI Express will exist in mobile
trim by the end of 2004, and in native form, no less.
HotHardware's PC Hardware Forum is all the rage! Are
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