4 ms·
I wonder what the actual latency improvements will be. If it's connected through PCI express, there will be a lower limit which is dictated by the bus. While re
by Unklejoe 10y ago
I wonder what the actual latency improvements will be. If it's connected through PCI express, there will be a lower limit which is dictated by the bus. While reducing the latency of the drive will still certainly matter, this latency introduced by the bus will serve to lessen the relative improvements with respect to SSDs.
PCI Express is packetized and it takes a little over 1 nanosecond per byte for the 3.0 version. I believe the minimum packet size is 20 bytes, but I'm not positive on that. It seems like the latency could never be less than 2 * (1 * 20) nanoseconds in the case of a random access, and this is before the latency of the drive itself is factored in. Surely there will be a few clock cycles required for the drive HW to decode the PCIe transaction and act upon it.
That being said, any latency improvement of the drive _will_ have a direct reduction in effective latency in the end, so it’s all good news to me. I’m just curious about the 1000x figure that’s being referenced everywhere.