my machine is suddenly extremely slow

[Frédéric Bron]

> hdparm -t /dev/sda
> hdparm -t /dev/sdb

OK, thanks, I have done a reference in good conditions (see below). I
will be able to compare when the PC slows done.
Frédéric

/dev/sda: Timing buffered disk reads: 1430 MB in  3.00 seconds = 476.63 MB/sec
/dev/sda: Timing buffered disk reads: 1406 MB in  3.00 seconds = 468.60 MB/sec
/dev/sda: Timing buffered disk reads: 1432 MB in  3.00 seconds = 476.72 MB/sec
/dev/sda: Timing buffered disk reads: 1406 MB in  3.00 seconds = 468.26 MB/sec
/dev/sda: Timing buffered disk reads: 1428 MB in  3.00 seconds = 475.63 MB/sec
/dev/sdb: Timing buffered disk reads: 306 MB in  3.01 seconds = 101.82 MB/sec
/dev/sdb: Timing buffered disk reads: 306 MB in  3.00 seconds = 102.00 MB/sec
/dev/sdb: Timing buffered disk reads: 306 MB in  3.00 seconds = 101.90 MB/sec
/dev/sdb: Timing buffered disk reads: 308 MB in  3.01 seconds = 102.19 MB/sec
/dev/sdb: Timing buffered disk reads: 308 MB in  3.02 seconds = 102.14 MB/sec