Is there anyway to force the expansion ports to Gen1, while keeping the host side Gen 2 or Gen 3
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OneStop Systems
Jan 16, 2020, 6:15:08 PM1/16/20
to One Stop Systems
Product: Dual x 8 and quad x8 gen 3 expansion cards
Question:
Is there anyway to force the expansion ports to Gen1, while keeping the host side Gen 2 or Gen 3.
We have found that if we force the PC to run all slots at Gen 1, the expansion side runs at gen 1, but for Gen 2 or Gen 3, the expansion runs at gen 2. Note there is a Gen 2 device that we connected to.
We would prefer to not have to run the PC bus at Gen 1 as we want to use your quad card and gen 1x8 on the PC side will may not be fast enough for our requirements
We also, don't understand why changing the PC side to Gen 1 changes the expansion side to Gen1.
Answer:
By PCI sig (special interest group that developed the PCI and PCIe specifications) systems linked together via a transparent bridge must "train down" to the lowest common path, i.e. the Gen speed and lane count available to both upstream and downstream devices. Therefore, when you force the host device to Gen1, all communication between that device and downstream devices, regardless of the downstream device's capability, will be at Gen1.
Our dual x8 and quad x8 host bus adapter cards, Gen speed is controlled by a) the capability of the switch and b) programming of its associated/controlling EEPROM and CPLD. In theory, it would be possible to create custom firmware to force these HBAs to Gen1, however even if this was done, if the up
Question:
Is there anyway to force the expansion ports to Gen1, while keeping the host side Gen 2 or Gen 3.
We have found that if we force the PC to run all slots at Gen 1, the expansion side runs at gen 1, but for Gen 2 or Gen 3, the expansion runs at gen 2. Note there is a Gen 2 device that we connected to.
We would prefer to not have to run the PC bus at Gen 1 as we want to use your quad card and gen 1x8 on the PC side will may not be fast enough for our requirements
We also, don't understand why changing the PC side to Gen 1 changes the expansion side to Gen1.
Answer:
By PCI sig (special interest group that developed the PCI and PCIe specifications) systems linked together via a transparent bridge must "train down" to the lowest common path, i.e. the Gen speed and lane count available to both upstream and downstream devices. Therefore, when you force the host device to Gen1, all communication between that device and downstream devices, regardless of the downstream device's capability, will be at Gen1.
Our dual x8 and quad x8 host bus adapter cards, Gen speed is controlled by a) the capability of the switch and b) programming of its associated/controlling EEPROM and CPLD. In theory, it would be possible to create custom firmware to force these HBAs to Gen1, however even if this was done, if the up
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