PCI Express* Add-in
Card Considerations
22
336521
Average Power Calculation
Interval Length in
microseconds(µs)
“T”
Ratio of Average Power1 in
Interval “T” Divided by
Maximum Sustain Power
Notes
≥ 1,000,000 µs (1 sec)
1
-
NOTES:
1.
R =
average
power
during
internal
T
Max
Sustained
Power
(
ie
.
TDP
)
.
2.
This is also the max ratio of instantaneous power relative to maximum sustained
power.
3.
ln() is the natural logarithm function.
4.
Add-in Card must at all times and concurrently adhere to power excursion limits for
all time interval lengths as well as the limits defined for Power Supply Rail
5.
Engineering Change Notice for up to 300 Watts (Work in Progress) will likely make
this table apply to all cards mounting the 12VHPWR connector.
Figure 3-1: PCI Express* CEM Add-in Card Power Excursion Limits Chart
3.1.1
PCIe* Add-in Card and PSU Power Budgets
Three dominant power demands dictate the total system power provisioning:
1.
CPU power consumption
2.
PCIe Add-in Card power level
Summary of Contents for ATX 3.0
Page 69: ...LFX12V Specific Guidelines 2 0 336521 69 Figure 12 2 Mechanical Details...
Page 70: ...LFX12V Specific Guidelines 2 0 70 336521 Figure 12 3 PSU Slot Feature Detail...
Page 71: ...LFX12V Specific Guidelines 2 0 336521 71 Figure 12 4 Recommended Chassis Tab Feature...
Page 77: ...SFX12V Specific Guidelines 4 0 336521 77 Figure 14 3 Top Mount Fan Profile Mechanical Outline...
Page 82: ...SFX12V Specific Guidelines 4 0 82 336521 Figure 14 10 PS3 Mechanical Outline...
Page 87: ...TFX12V Specific Guidelines 3 0 336521 87 Figure 15 6 Suggested Mounting Tab chassis feature...
