Heatsinks for the FMC Fine Delay
This page summarizes the heatsink testing results.
Fine Delay on SVEC (lab test)
Test evironment:*
- crate: 20-slot Wiener VME64x
- crate contents: single SVEC in VME slot 5 with the card under test in FMC slot 2 and FMC TDC in FMC slot 1
- fan speed: 1200 RPM (minimum)
- ambient temperature: 20 deg Celsius
- warm-up time: 8 minutes
Results:*
| Serial No | Configuration | Temperature (degrees Celsius)
|
| CR37 | no heatsink | 59.7 |
| CR09 | small heatsinks on delay and PLL chips | 51.7 |
| CR01 | big heatsink in the rear of the card | 58.6 |
| CR03 | both heatsinks | 52.3 |
Conclusions:*
- big heatsink gives very little temperature drop (1 degC can be
considered measurement error). See the section with thermal camera
measurements for details.
- small heatsinks glued on the chips give improvement of 8 degrees C.
Detailed temperature measurements on different platforms
Note:* All temperatures in degrees Celsius.
Test environment
- VME: Wiener and Elma crates, with up to 7 SVECs (14 Fine Delays)
installed in subsequent slots. Whenever possible, different
combinations
of VME slots and fan speeds were used. All crates used a MEN A20
controller. Ambient temp 26-28.
- PCI Express: Kontron industrial PC, with 5 SPECs and 5 Fine Delays. Ambient temp 19-20.
- Temperatures were logged over time to make sure they have settled up
before taking measurements. The first stable sample (with less than 1
degree temperature change over 1 minute) was used for the statistics.
- Unused slots were covered to ensure maximum airflow through the FMCs.
Data:
Wiener 21-slot VME64x crate, fans at 1200 rpm (minimum speed):*
Slots 4-10:
| Slot/FMC | 4/1 | 4/2 | 5/1 | 5/2 | 6/1 | 6/2 | 7/1 | 7/2 | 8/1 |
8/2 | 9/1 | 9/2 | 10/1 | 10/2 |
| Temperature | 65.69 | 71.38 | 56.88 | 66.25 | 50.69 | 63.88 |
51.19 | 63.62 | 58.62 | 73.25 | 61.44 | 71.00 | 50.12 | 59.62 |
Slots 9-15:
| Slot/FMC | 9/1 | 9/2 | 10/1 | 10/2 | 11/1 | 11/2 | 12/1 | 12/2 |
13/1 | 13/2 | 14/1 | 14/2 | 15/1 | 15/2 |
| Temperature | 62.00 | 71.12 | 60.19 | 74.31 | 61.25 | 73.75 |
51.94 | 65.12 | 48.75 | 60.88 | 51.31 | 62.75 | 52.12 | 64.06 |
Wiener 21-slot VME64x crate, fans at 3600 rpm (maximum speed):*
Slots 4-10:
| Slot/FMC | 4/1 | 4/2 | 5/1 | 5/2 | 6/1 | 6/2 | 7/1 | 7/2 | 8/1 |
8/2 | 9/1 | 9/2 | 10/1 | 10/2 |
| Temperature | 52.75 | 57.06 | 45.31 | 51.56 | 39.31 | 48.31 |
40.38 | 48.31 | 47.38 | 58.81 | 49.94 | 55.00 | 40.75 | 46.12 |
Slots 9-15:
| Slot/FMC | 9/1 | 9/2 | 10/1 | 10/2 | 11/1 | 11/2 | 12/1 | 12/2 |
13/1 | 13/2 | 14/1 | 14/2 | 15/1 | 15/2 |
| Temperature | 49.44 | 55.00 | 48.81 | 56.50 | 49.88 | 55.00 |
41.44 | 50.88 | 40.69 | 50.12 | 41.31 | 48.12 | 42.75 | 49.00 |
Elma 18-slot VME64x crate, default fan configuration:*
Slots 4-10:
| Slot/FMC | 4/1 | 4/2 | 5/1 | 5/2 | 6/1 | 6/2 | 7/1 | 7/2 | 8/1 |
8/2 | 9/1 | 9/2 | 10/1 | 10/2 |
| Temperature | 57.44 | 62.56 | 49.75 | 59.06 | 44.50 | 53.88 |
46.00 | 56.38 | 62.00 | 70.94 | 66.44 | 73.69 | 46.69 | 56.31 |
Slots 9-15:
| Slot/FMC | 9/1 | 9/2 | 10/1 | 10/2 | 11/1 | 11/2 | 12/1 | 12/2 |
13/1 | 13/2 | 14/1 | 14/2 | 15/2 |
| Temperature | 66.00 | 72.06 | 66.88 | 73.56 | 57.38 | 65.44 |
46.94 | 59.88 | 45.31 | 56.31 | 50.56 | 60.06 | 59.31 |
Elma 6-slot VME64x crate, default fan configuration:*
| Slot/FMC | 2/1 | 2/2 | 3/1 | 3/2 | 4/1 | 4/2 | 5/1 | 5/2 | 6/1 |
6/2 |
| Temperature | 77.69 | 72.38 | 77.31 | 69.75 | 66.88 | 60.12 |
82.06 | 74.31 | 90.00 | 83.19 |
Kontron KISS 6U industrial PC:*
Slot | 1 | 2 | 3 | 7 | 8 |
Temperature | 89.25 | 92.56 | 98.75 | 88.56 | 79.50 |
Summary
Platform | Min temp | Max temp | Mean temp | Max-min | Ambient | Mean-ambient |
Wiener (1200 rpm) | 48.7 | 74.3 | 61.5 | 25.6 | 28 | 33.5 |
Wiener (3600 rpm) | 39.3 | 58.8 | 48.5 | 19.5 | 28 | 20.5 |
Elma 18-slot | 44.5 | 73.7 | 58.7 | 29.2 | 28 | 30.7 |
Elma 6-slot | 60.1 | 90.0 | 75.3 | 29.9 | 28 | 47.3 |
Kontron | 79.5 | 98.8 | 19.2 | 89.7 | 20 | 69.7 |
Conclusions
- Cards in the middle slots (8-10) are the worst (25 degC difference over slots 7 and 12). Uneven air flow in the crate?
- FMC1 is approximately 8-10 degrees cooler than FMC2. FMC1 is closer to the fans and obstructs air flow to FMC2.
- Large temperature spans in VME crates suggest uneven air flow between different slots.
- Keeping the fans speed at a maximum (Wiener) results with reasonable
cooling (worst temperature: 59).
- On Elma 6U and Kontron PC platforms, the temperatures are
unacceptable and exceed the components rating (-40 ... +85). Heatsink is
needed.
Thermal imaging
tbc
h2. Thermal camera measurements