<s>
In	O
computer	O
graphics	O
,	O
a	O
video	B-Device
card	I-Device
's	O
pixel	B-Algorithm
fillrate	B-General_Concept
refers	O
to	O
the	O
number	O
of	O
pixels	B-Algorithm
that	O
can	O
be	O
rendered	O
on	O
the	O
screen	O
and	O
written	O
to	O
video	O
memory	O
in	O
one	O
second	O
.	O
</s>
<s>
Pixel	B-Algorithm
fillrates	B-General_Concept
are	O
given	O
in	O
megapixels	O
per	O
second	O
or	O
in	O
gigapixels	B-Algorithm
per	O
second	O
(	O
in	O
the	O
case	O
of	O
newer	O
cards	O
)	O
,	O
and	O
are	O
obtained	O
by	O
multiplying	O
the	O
number	O
of	O
render	B-General_Concept
output	I-General_Concept
units	I-General_Concept
(	O
ROPs	O
)	O
by	O
the	O
clock	O
frequency	O
of	O
the	O
graphics	B-Architecture
processing	I-Architecture
unit	I-Architecture
(	O
GPU	B-Architecture
)	O
of	O
a	O
video	B-Device
card	I-Device
.	O
</s>
<s>
A	O
similar	O
concept	O
,	O
texture	O
fillrate	B-General_Concept
,	O
refers	O
to	O
the	O
number	O
of	O
texture	O
map	O
elements	O
(	O
texels	O
)	O
the	O
GPU	B-Architecture
can	O
map	O
to	O
pixels	B-Algorithm
in	O
one	O
second	O
.	O
</s>
<s>
Texture	O
fillrate	B-General_Concept
is	O
obtained	O
by	O
multiplying	O
the	O
number	O
of	O
texture	B-General_Concept
mapping	I-General_Concept
units	I-General_Concept
(	O
TMUs	O
)	O
by	O
the	O
clock	O
frequency	O
of	O
the	O
GPU	B-Architecture
.	O
</s>
<s>
Texture	O
fillrates	B-General_Concept
are	O
given	O
in	O
mega	O
or	O
gigatexels	O
per	O
second	O
.	O
</s>
<s>
However	O
,	O
there	O
is	O
no	O
full	O
agreement	O
on	O
how	O
to	O
calculate	O
and	O
report	O
fillrates	B-General_Concept
.	O
</s>
<s>
Another	O
possible	O
method	O
is	O
to	O
multiply	O
the	O
number	O
of	O
pixel	B-Algorithm
pipelines	O
by	O
the	O
GPU	B-Architecture
's	O
clock	O
frequency	O
.	O
</s>
<s>
The	O
actual	O
fillrate	B-General_Concept
depends	O
on	O
many	O
other	O
factors	O
.	O
</s>
<s>
In	O
the	O
past	O
,	O
the	O
fillrate	B-General_Concept
has	O
been	O
used	O
as	O
an	O
indicator	O
of	O
performance	O
by	O
video	B-Device
card	I-Device
manufacturers	O
such	O
as	O
ATI	O
and	O
NVIDIA	O
,	O
however	O
,	O
the	O
importance	O
of	O
the	O
fillrate	B-General_Concept
as	O
a	O
measurement	O
of	O
performance	O
has	O
declined	O
as	O
the	O
bottleneck	O
in	O
graphics	O
applications	O
has	O
shifted	O
.	O
</s>
<s>
Scene	O
complexity	O
can	O
be	O
increased	O
by	O
overdrawing	O
,	O
which	O
happens	O
when	O
an	O
object	O
is	O
drawn	O
to	O
the	O
frame	B-Algorithm
buffer	I-Algorithm
,	O
and	O
another	O
object	O
(	O
such	O
as	O
a	O
wall	O
)	O
is	O
then	O
drawn	O
on	O
top	O
of	O
it	O
,	O
covering	O
it	O
up	O
.	O
</s>
<s>
When	O
a	O
sequence	O
of	O
scenes	O
is	O
extremely	O
complex	O
(	O
many	O
pixels	B-Algorithm
have	O
to	O
be	O
drawn	O
for	O
each	O
scene	O
)	O
,	O
the	O
frame	O
rate	O
for	O
the	O
sequence	O
may	O
drop	O
.	O
</s>
<s>
When	O
designing	O
graphics	O
intensive	O
applications	O
,	O
one	O
can	O
determine	O
whether	O
the	O
application	O
is	O
fillrate-limited	O
(	O
or	O
shader	O
limited	O
)	O
by	O
seeing	O
if	O
the	O
frame	O
rate	O
increases	O
dramatically	O
when	O
the	O
application	O
runs	O
at	O
a	O
lower	O
resolution	B-General_Concept
or	O
in	O
a	O
smaller	O
window	O
.	O
</s>
