"Paul" wrote in message
Thanks again Ed, there are 3 settings to change in BIOS, OnChip SATA
Controller, OnChip SATA Type & OnChip SATA Port 4/5 Mode.
Enabled 1st and the other 2 to AHCI. Doesn't appear to have changed much,
Windows Experience Index shows HDD as 5.9 which is the same as before.
HDD is pulling down overall index figure which is why I was hoping
changing BIOS would speed it up a bit.
Actually, be careful what you wish for.
http://en.wikipedia.org/wiki/Ahci
AHCI includes Native Command Queueing (NCQ), which is the ability to
complete commands out of sequence. It allows the shortest path to
be planned for head movement - but that only happens, when the "queue
builds up".
http://en.wikipedia.org/wiki/Native_Command_Queuing
In a server situation, with ten people doing ten different things, such
a feature can be a big win. The disk can't possibly keep up with what
the ten people are doing, so the queue builds. And when it does, the
controller board on the hard drive, looks at the "to do list", and
picks the items that have the least head movement required. That
prevents unnecessary excursions of the head and reduces the overall
time to complete the "to do list".
However, you, as a single user, your typical usage pattern has a queue
depth of one. With no queue to "sort" into the most desirable form,
the commands complete in the same time as they did before.
AHCI has a small amount of overhead associated with it. It means,
on average, processing commands on AHCI is slower. If the queue builds
up, it "pays for its keep". If there is no queue, then you lose a
tiny bit in speed.
Now, some users type real fast, are whizzing around doing ten different
things at once. Perhaps their queue depth is greater than one. But
a lot of users, they're "one thing at a time" kind of people, and
for them, NCQ isn't a big deal.
Many SSD owners select AHCI, because the Microsoft version of AHCI
driver (called MSAHCI), supports the TRIM command. And that is the
main reason they'd be looking for that mode of operation, as much as
anything else.
http://en.wikipedia.org/wiki/TRIM_command
HTH,
Paul
Anyone know a similar tweak for XP? I have Windows 7 and XP systems
that I switch between in the same box.
Thanks.