Koji asked me assemble a detailed breakdown of the parts received from LHO, which I do based on the high-res photos that Gautam posted of the shipment.
Parts in hand:
| Qty |
Part |
Note(s) |
| 2 |
Chassis body |
|
| 2 |
Power board and cooling fans |
As noted in 15763, these have the standard LIGO +24V input connector which we may want to change |
| 2 |
IO interface backplane |
|
| 2 |
PCIe backplane |
|
| 2 |
Chassis-side OSS PCIe x4 card |
|
| 2 |
CX4 fiber cables |
These were not requested and are not needed |
Parts still needed:
| Qty |
Part |
Note(s) |
| 2 |
Host-side OSS PCIe x4 card |
These were requested but missing from the LHO shipment |
| 2 |
Timing slave |
These were not originally requested, but we have recently learned they will be replaced at LHO soon |
Issue with PCIe slots in new FEs
Also, I looked into the mix-up regarding the number of PCIe slots in the new Supermicro servers. The motherboard actually has six PCIe slots and is on the CDS list of boards known to be compatible. The mistake (mine) was in selecting a low-profile (1U) chassis that only exposes one of these slots. But at least it's not a fundamental limitation.
One option is to install an external PCIe expansion chassis that would be rack-mounted right above the FE. It is automatically configured by the system BIOS, so doesn't require any special drivers. It also supports hot-swapping of PCIe cards. There are also cheap ribbon-cable riser cards that would allow more cards to be connected for testing, although this is not as great for permanent mounting.
It may still be better to use the machines offered by Keith Thorne from LLO, as they're more powerful anyway. But if there is going to be an extended delay before those can be received, we should be able to use the machines we already have in conjunction with one of these PCIe expansion options. |