Very low transfer rates on my HD

I have one HD Samsung HD501LJ SATA 2.5 (boot) that is very, very slow on transfer rate.
On the same PC, I have another two HD, (one is same model) and both get around 80mb/s.

I have run seaTools (from seagate) and all test PAST, no issues.

Anyway this is what I get with HD Tune Pro:
Transfer rate minimum 0.4 MB/s
Transfer rate maximum 3.7 MB/s
Transfer rate average 3.6 MB/s
CPU usage 50.0%
access time 14.2 ms
HD Tune Pro: SAMSUNG HD501LJ Health

ID Current Worst Threshold Data Status
(01) Raw Read Error Rate 100 100 51 2 ok
(03) Spin Up Time 100 100 15 7360 ok
(04) Start/Stop Count 94 94 0 6277 ok
(05) Reallocated Sector Count 253 253 10 0 ok
(07) Seek Error Rate 253 253 51 0 ok
(08) Seek Time Performance 253 253 15 0 ok
(09) Power On Hours Count 100 100 0 17124 ok
(0A) Spin Retry Count 253 253 51 0 ok
(0B) Calibration Retry Count 253 100 0 0 ok
(0C) Power Cycle Count 95 95 0 5774 ok
(BB) Uncorrectable Error Count 73 73 0 28 ok
(BC) Command Timeout 253 253 0 0 ok
(BE) Airflow Temperature 62 47 0 38 ok
(C2) Temperature 124 79 0 38 ok
(C3) Hardware ECC Recovered 100 100 0 549058656 ok
(C4) Reallocated Event Count 253 253 0 0 ok
(C5) Current Pending Sector 253 100 0 0 ok
(C6) Offline Uncorrectable 253 253 0 0 ok
(C7) Interface CRC Error Count 200 200 0 0 ok
(C8) Write Error Rate 100 100 0 0 ok
(C9) Soft Read Error Rate 100 100 0 0 ok
(CA) Data Address Marker errors 253 253 0 0 ok

Health Status : ok

ECC values are very high but test was PASS.
I have no noise and is working (no error reading or saving) but speed is unsense, very slow.

Any help that you can provide me? Is the HD safe? is damage?
This is my boot disk, many thanks for any suggestion.

pictures