On 14/11/2018 23.07, jdd@dodin.org wrote:
Le 14/11/2018 à 21:30, Patrick Shanahan a écrit :
* jdd@dodin.org <> [11-14-18 14:20]:
[ 3.153819] ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 3.154594] ata5: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
just guessing but dvd reads are slow compared to rust or solid state drives and the caddy mfgr doesn't support connecting above sata1, 300mps
actually 3.0 Gbps
3 Gbps is about 300 MBps :-) Yes, I know that one byte is 8 bits, not ten, but there is some overhead on serial buses and often the 10 bit ratio better matches results.
but interfaces seems to be the same:
[ 2.844380] ata3: SATA max UDMA/133 abar m2048@0xf7a1a000 port 0xf7a1a200 irq 32
[ 2.844382] ata5: SATA max UDMA/133 abar m2048@0xf7a1a000 port 0xf7a1a300 irq 32
is there a logical way to fix the speed or is it purely mechanical? (the caddy itself is given for 6 Gbps
hdparm was used in the past to adjust these things, the -X parameters I think. I'm not sure it applies to SATA. The speed of the bus is, I think, a motherboard characteristic, and it is possible that if there is an interface dedicated to the DVD it has slower ratings to save some cost. -- Cheers / Saludos, Carlos E. R. (from 42.3 x86_64 "Malachite" at Telcontar)