Qca at various airflows for 21264/ev67 – Compaq 21264 User Manual
Page 252
10–2
Thermal Management
Alpha 21264/EV67 Hardware Reference Manual
Operating Temperature
Table 10–2 lists the values for the center of heat-sink-to-ambient (
θ
c
a) for the 21264/
EV67 587-pin PGA. Tables 10–3 through 10–8 show the allowable T
a
(without
exceeding T
c
) at various airflows.
Table 10–2
θ
c
a at Various Airflows for 21264/EV67
Airflow (linear ft/min)
100
200
400
800
1000
θ
c
a
with heat sink type 1 (
°
C/W)
2.0
1.2
0.65
0.40
0.37
θ
c
a
with heat sink type 2 (
°
C/W)
1.4
0.78
0.45
0.33
0.31
θ
c
a
with heat sink type 3
1
(
°
C/W)
1
Heat sink type 3 has a 80 mm
×
80 mm
×
15 mm fan attached.
— 0.38 —
Table 10–3 Maximum T
a
for 21264/EV67 @ 600 MHz and @ 2.0 V with Various Airflows
Airflow (linear ft/min)
100
200
400
800
1000
Maximum T
a
with heat sink type 1 (
°
C)
—
—
37.3
53.8
55.8
Maximum T
a
with heat sink type 2 (
°
C)
—
28.7
50.5
58.4
59.7
Maximum T
a
with heat sink type 3
1
(
°
C)
1
Heat sink type 3 has a 80 mm
×
80 mm
×
15 mm fan attached.
— 55.1 —
Table 10–4 Maximum T
a
for 21264/EV67 @ 667 MHz and @ 2.0 V with Various Airflows
Airflow (linear ft/min)
100
200
400
800
1000
Maximum T
a
with heat sink type 1 (
°
C)
—
—
30.7
48.9
51.1
Maximum T
a
with heat sink type 2 (
°
C)
—
21.2
45.3
54.0
55.5
Maximum T
a
with heat sink type 3
1
(
°
C)
1
Heat sink type 3 has a 80 mm
×
80 mm
×
15 mm fan attached.
— 50.4 —
Table 10–5 Maximum T
a
for 21264/EV67 @ 700 MHz and @ 2.0 V with Various Airflows
Airflow (linear ft/min)
100
200
400
800
1000
Maximum T
a
with heat sink type 1 (
°
C)
—
—
26.9
46.1
48.4
Maximum T
a
with heat sink type 2 (
°
C)
—
—
42.2
51.5
53.0
Maximum T
a
with heat sink type 3
1
(
°
C)
1
Heat sink type 3 has a 80 mm
×
80 mm
×
15 mm fan attached.
— 47.6 —
Table 10–6 Maximum T
a
for 21264/EV67 @ 733 MHz and @ 2.0 V with Various Airflows
Airflow (linear ft/min)
100
200
400
800
1000
Maximum T
a
with heat sink type 1 (
°
C)
—
—
24.0
44.0
46.4
Maximum T
a
with heat sink type 2 (
°
C)
—
—
40.0
49.6
51.2
Maximum T
a
with heat sink type 3
1
(
°
C)
1
Heat sink type 3 has a 80 mm
×
80 mm
×
15 mm fan attached.
— 45.6 —