<s>
HyperZ	B-Device
is	O
the	O
brand	O
for	O
a	O
set	O
of	O
processing	O
techniques	O
developed	O
by	O
ATI	O
Technologies	O
and	O
later	O
Advanced	O
Micro	O
Devices	O
and	O
implemented	O
in	O
their	O
Radeon-GPUs	O
.	O
</s>
<s>
HyperZ	B-Device
was	O
announced	O
in	O
November	O
2000	O
and	O
was	O
still	O
available	O
in	O
the	O
TeraScale-based	O
Radeon	B-Device
HD	I-Device
2000	O
Series	O
and	O
in	O
current	O
Graphics	O
Core	O
Next-based	O
graphics	O
products	O
.	O
</s>
<s>
On	O
the	O
Radeon	B-Device
R100-based	O
cores	O
,	O
Radeon	B-Device
DDR	O
through	O
7500	O
,	O
where	O
HyperZ	B-Device
debuted	O
,	O
ATI	O
claimed	O
a	O
20%	O
improvement	O
in	O
overall	O
rendering	O
efficiency	O
.	O
</s>
<s>
They	O
stated	O
that	O
with	O
HyperZ	B-Device
,	O
Radeon	B-Device
could	O
be	O
said	O
to	O
offer	O
1.5	O
gigatexels	O
per	O
second	O
fillrate	O
performance	O
instead	O
of	O
the	O
card	O
's	O
apparent	O
theoretical	O
rate	O
of	O
1.2	O
gigatexels	O
.	O
</s>
<s>
In	O
testing	O
it	O
was	O
shown	O
that	O
HyperZ	B-Device
did	O
indeed	O
offer	O
a	O
tangible	O
performance	O
improvement	O
that	O
allowed	O
the	O
less	O
endowed	O
Radeon	B-Device
to	O
keep	O
up	O
with	O
the	O
less	O
efficient	O
GeForce	O
2	O
GTS	O
.	O
</s>
<s>
HyperZ	B-Device
consists	O
of	O
three	O
mechanisms	O
:	O
</s>
<s>
Z	O
compression	O
The	O
Z-buffer	O
is	O
stored	O
in	O
a	O
lossless	B-Algorithm
compressed	O
format	O
to	O
minimize	O
the	O
Z-Buffer	O
bandwidth	O
as	O
Z	O
read	O
or	O
writes	O
are	O
taking	O
place	O
.	O
</s>
<s>
The	O
compression	O
scheme	O
ATI	O
used	O
on	O
Radeon	B-Device
8500	I-Device
operated	O
20%	O
more	O
effectively	O
than	O
on	O
the	O
original	O
Radeon	B-Device
and	O
Radeon	B-Device
7500	I-Device
.	O
</s>
<s>
On	O
Radeon	B-Device
8500	I-Device
,	O
ATI	O
claimed	O
that	O
this	O
process	O
could	O
clear	O
the	O
Z-Buffer	O
up	O
to	O
approximately	O
64	O
times	O
faster	O
than	O
that	O
of	O
a	O
card	O
without	O
fast	O
Z	O
clear	O
.	O
</s>
<s>
This	O
allows	O
useless	O
pixels	O
to	O
be	O
thrown	O
out	O
early	O
(	O
early	O
Z	O
reject	O
)	O
,	O
before	O
the	O
Radeon	B-Device
has	O
to	O
render	O
them	O
.	O
</s>
<s>
With	O
each	O
new	O
microarchitecture	B-General_Concept
,	O
ATI	O
has	O
revised	O
and	O
improved	O
the	O
technology	O
.	O
</s>
