Help to interpret HD Tune results please

[Terry Pinnell]

I have two identical 750 GB Samsung HDs on this Quad Core 2.66 GHz, 4 GB
RAM PC, under Win XP.

C: holds my OS and main data and I: is mainly backup. I also have two
external WD HDs, 1 TB and 2 TB.

I'm trying to find the reason for slow performance in several applications
(I could provide more detail). So I downloaded and ran HD Tune 2.55 to see
in particular if my main OS drive C: could be the cause.

It LOOKS to me as if my suspicion was justified, as C: seems significantly
slower than I: But I'm not technically savvy in this area and unfamiliar
with this neat utility. So could someone advise me please? Here are the
relevant results:

C: Benchmark
https://dl.dropbox.com/u/4019461/C-Bench-HDTune.jpg

I: Benchmark for comparison
https://dl.dropbox.com/u/4019461/I-Bench-HDTune.jpg

C: Info
https://dl.dropbox.com/u/4019461/C-Info-HDTune.jpg

C: Health
https://dl.dropbox.com/u/4019461/C-Health-HDTune.jpg

Error Scans
Both C: and I: (and both external drives) gave no errors, solid green
display.

Q1 If C: is indeed considered by the experts to be performing abnormally
badly, what can be the explanation? And what if anything can be done?
(Note: Last night I set chkdsk C: /f, rebooted and went to bed. I did the
test shortly after getting back to my PC this morning.)

Q2 Why do transfer rates drop during the test, especially C:?

Q3 Why do the access times for C: vary so much?

Q4 Are the temperatures OK?


All advice would be much appreciated please.

 

[Jaimie Vandenbergh]

I have two identical 750 GB Samsung HDs on this Quad Core 2.66 GHz, 4 GB
RAM PC, under Win XP.

C: holds my OS and main data and I: is mainly backup. I also have two
external WD HDs, 1 TB and 2 TB.

I'm trying to find the reason for slow performance in several applications
(I could provide more detail). So I downloaded and ran HD Tune 2.55 to see
in particular if my main OS drive C: could be the cause.

It LOOKS to me as if my suspicion was justified, as C: seems significantly
slower than I: But I'm not technically savvy in this area and unfamiliar
with this neat utility. So could someone advise me please? Here are the
relevant results:

C: Benchmark
https://dl.dropbox.com/u/4019461/C-Bench-HDTune.jpg

I: Benchmark for comparison
https://dl.dropbox.com/u/4019461/I-Bench-HDTune.jpg

C: Info
https://dl.dropbox.com/u/4019461/C-Info-HDTune.jpg

According to this, your SATAII drive is operating in UDMA133 mode -
probably means it's in IDE emulation mode which would explain the mild
slowdown all by itself - IDE mode is nothing like as clever as SATAII
mode particularly for a drive which is being multitasked over, which
the boot drive always will.

Enabling full AHCI mode for the boot drive in XP is a bit of an
annoyance, and requires some messing about. I've always slipstreamed
it into my XP install disk in the past, so I'll leave further details
to people who have done it the hard way.

C: Health
https://dl.dropbox.com/u/4019461/C-Health-HDTune.jpg

Error Scans
Both C: and I: (and both external drives) gave no errors, solid green
display.

Q1 If C: is indeed considered by the experts to be performing abnormally
badly, what can be the explanation? And what if anything can be done?
(Note: Last night I set chkdsk C: /f, rebooted and went to bed. I did the
test shortly after getting back to my PC this morning.)

It doesn't actually seem particularly bad.

Q2 Why do transfer rates drop during the test, especially C:?

The test starts at the outer edge of the disk, where data is going
past at a higher rate per second. As it moves to the centre, that
linear rate drops.

Q3 Why do the access times for C: vary so much?

Because it's your boot drive and there are loads of other processes
twiddling it while you're testing.

Q4 Are the temperatures OK?

If they were degress centigrade the drives would have long since died!
Looks like it's the raw data (perhaps showing 100-temp?), if you go
look at the top of the page it has real centigrade temp for the drive.

All in all, I'd say that you won't get more than a few percent better
performance out of this drive by looking at it at the lowest level.
More likely to improve performance by the usual: defrag, defrag the
swapfile, throw it away and put in an SSD instead...

Cheers - Jaimie

 

[Mike Tomlinson]

C: Health
https://dl.dropbox.com/u/4019461/C-Health-HDTune.jpg

Correcting many errors, if the SMART data can be believed. Temperature
is OK at 29C, but I don't understand how HDTune derives 29 degrees from
the SMART data, which says 71 for temperature.

Download and install Defraggler from piriform.com. You needn't run
defrag, just choose the drive and click the Health tab. What does that
have to say about C:'s SMART data?

It would help if you gave us the equivalent screenshot for I: for
comparison.

 

[Jaimie Vandenbergh]

Correcting many errors, if the SMART data can be believed.

Uh... where? Remember you're looking at the "current" field not "data"
for data (thanks, SMART), and that mfr's can put the SMART data in any
impenetrable form they like...

Current and Worst being 100/100 *almost* certainly means zero events.

Temperature
is OK at 29C, but I don't understand how HDTune derives 29 degrees from
the SMART data, which says 71 for temperature.

That's another clue - temp is counting backwards from 100, likely the
others do too.

Cheers - Jaimie

 

[Terry Pinnell]

According to this, your SATAII drive is operating in UDMA133 mode -
probably means it's in IDE emulation mode which would explain the mild
slowdown all by itself - IDE mode is nothing like as clever as SATAII
mode particularly for a drive which is being multitasked over, which
the boot drive always will.

Enabling full AHCI mode for the boot drive in XP is a bit of an
annoyance, and requires some messing about. I've always slipstreamed
it into my XP install disk in the past, so I'll leave further details
to people who have done it the hard way.

Thanks Jaimie.

I found the following, although I don't know whether I'm confident enough
to try it. Or for that matter motivated enough - although that difference
in performance (of some 25%?) looks quite a lot to me.

http://www.neowin.net/news/neowin-guide-how-to-change-from-ide-to-ahci-without-reinstalling-windows

It doesn't actually seem particularly bad.


The test starts at the outer edge of the disk, where data is going
past at a higher rate per second. As it moves to the centre, that
linear rate drops.

I've now downloaded another disk testing tool called HD Speed. The results
with that seem to show the reverse, presumably that starts scanning from
the inside?
https://dl.dropbox.com/u/4019461/Both-Comparison.jpg

C is still shown as 17% slower than I, although that's not such a large
difference as the 25% reported by HD Tune.

Because it's your boot drive and there are loads of other processes
twiddling it while you're testing.


If they were degress centigrade the drives would have long since died!
Looks like it's the raw data (perhaps showing 100-temp?), if you go
look at the top of the page it has real centigrade temp for the drive.

All in all, I'd say that you won't get more than a few percent better
performance out of this drive by looking at it at the lowest level.
More likely to improve performance by the usual: defrag, defrag the
swapfile, throw it away and put in an SSD instead...

It's defragged with Perfect Disk 'constantly'. Not sure about the swapfile
(over 3 GB and on I:, not C. SSD will have to wait until next PC.

 

[Jaimie Vandenbergh]

Thanks Jaimie.

I found the following, although I don't know whether I'm confident enough
to try it. Or for that matter motivated enough - although that difference
in performance (of some 25%?) looks quite a lot to me.

http://www.neowin.net/news/neowin-guide-how-to-change-from-ide-to-ahci-without-reinstalling-windows

That's rather simpler than I remembered - good!

I've now downloaded another disk testing tool called HD Speed. The results
with that seem to show the reverse, presumably that starts scanning from
the inside?
https://dl.dropbox.com/u/4019461/Both-Comparison.jpg

C is still shown as 17% slower than I, although that's not such a large
difference as the 25% reported by HD Tune.

It's rather like having two clocks, you're never quite sure what the
time is... All benchmarking tools will have different results as they
come by them in a different way. Shrug.

It's defragged with Perfect Disk 'constantly'. Not sure about the swapfile
(over 3 GB and on I:, not C. SSD will have to wait until next PC.

Give the SATA conversion a go then - just remember to take a full
backup beforehand, as you would before doing anything major with a
disk.

And there's no reason not to go SSD now, you can always bring it
forward to a new machine.

However! Really, the place we should have started was by asking about
how the poor performance exhibits itself. Can you give some detail?
Slow boots and application launches tend to be down to software/OS
config issues more than hardware.

Cheers - Jaimie

 

[Terry Pinnell]

Correcting many errors, if the SMART data can be believed. Temperature
is OK at 29C, but I don't understand how HDTune derives 29 degrees from
the SMART data, which says 71 for temperature.

Download and install Defraggler from piriform.com. You needn't run
defrag, just choose the drive and click the Health tab. What does that
have to say about C:'s SMART data?

It would help if you gave us the equivalent screenshot for I: for
comparison.

Thanks Mike.

Yes, those temperatures are odd. The Health report numbers are clearly F,
but as 29C is about 84F that implies that to average that value at some
point it must have been around 100F. Perhaps the 'Worst' column shows
'Best' (coolest) by mistake?

Here's the comparison you requested. (Note that I subsequently enabled the
option to show C and F temps.)
https://dl.dropbox.com/u/4019461/Health-Comparison.jpg

 

[Terry Pinnell]

However! Really, the place we should have started was by asking about
how the poor performance exhibits itself. Can you give some detail?
Slow boots and application launches tend to be down to software/OS
config issues more than hardware.

Two areas in particular that I'm getting poor performance suddenly.

1. Whenever I record video with FRAPS (or CamStudio, so the capture
application is not the issue), such as from Google Earth or a desktop
tutorial, whatever, the frame rate drops to around 5-7 instead of its
usual 20-30. I THOUGHT the cause was simply my recent upgrade to the
latest nVidia diver 310.90, but after using roll back I STILL got the
problem. And I've tried several other versions too.

2. My Av program, Avira Antivurus Free is scanning extremely slowly.

 

[Jaimie Vandenbergh]

Two areas in particular that I'm getting poor performance suddenly.

1. Whenever I record video with FRAPS (or CamStudio, so the capture
application is not the issue), such as from Google Earth or a desktop
tutorial, whatever, the frame rate drops to around 5-7 instead of its
usual 20-30. I THOUGHT the cause was simply my recent upgrade to the
latest nVidia diver 310.90, but after using roll back I STILL got the
problem. And I've tried several other versions too.

I assume you're recording to C:, otherwise the HDD wouldn't be
relevant. Does it improve when you dump the video to the I: drive?

2. My Av program, Avira Antivurus Free is scanning extremely slowly.

Again, is it fast scanning I:? Copy your Windows or Program Files
folder over to I: if you want a more comparable test.

Cheers - Jaimie

 

[Mike Tomlinson]

Yes, those temperatures are odd. The Health report numbers are clearly F,

That was my first thought too (and the numbers are about right), but I
think Jaimie is correct, and it's the way SMART data is presented, with
100 being the nominal value.

What's reassuring is that your latest screenshot shows C: and I: having
the same temperature values. That's good, something you would expect if
they are both mounted in the same case.

Your C drive shows one reallocated sector, but this is nothing to be
concerned about. if the "Current Pending Sector" count were showing
something other than the nominal value of 100, it might possibly
indicate a developing problem, but it isn't.

Personally, I don't believe changing from IDE to AHCI mode is going to
result in a 25% performance improvement, but could be wrong. It's more
likely to be in the single figures. I'm still running three drives (two
SSD, one spinner) in IDE mode on XP but am reluctant to fiddle while it
all is working. If I do take the plunge I'll take benchmarks before and
after and post here.

 

[Jaimie Vandenbergh]

That was my first thought too (and the numbers are about right), but I
think Jaimie is correct, and it's the way SMART data is presented, with
100 being the nominal value.

What's reassuring is that your latest screenshot shows C: and I: having
the same temperature values. That's good, something you would expect if
they are both mounted in the same case.

Your C drive shows one reallocated sector,

I'm not sure it does... hard to interpret, but I'd expect Current to
drop to 90 or something if there were any actually reallocated.

Something dedicated to being a SMART reader might do a better job of
revealing the actual results!

Cheers - Jaimie

 

[Terry Pinnell]

That was my first thought too (and the numbers are about right), but I
think Jaimie is correct, and it's the way SMART data is presented, with
100 being the nominal value.

What's reassuring is that your latest screenshot shows C: and I: having
the same temperature values. That's good, something you would expect if
they are both mounted in the same case.

Your C drive shows one reallocated sector, but this is nothing to be
concerned about. if the "Current Pending Sector" count were showing
something other than the nominal value of 100, it might possibly
indicate a developing problem, but it isn't.

Personally, I don't believe changing from IDE to AHCI mode is going to
result in a 25% performance improvement, but could be wrong. It's more
likely to be in the single figures. I'm still running three drives (two
SSD, one spinner) in IDE mode on XP but am reluctant to fiddle while it
all is working. If I do take the plunge I'll take benchmarks before and
after and post here.

Thanks Mike. I'm not brave enough to make that mode change, especially
after reading further about XP sensitivity to this, BSODs etc!

But what about this UDMA 6 versus 7?
https://dl.dropbox.com/u/4019461/C-Info-HDTune.jpg

 

[Jaimie Vandenbergh]

Thanks Mike. I'm not brave enough to make that mode change, especially
after reading further about XP sensitivity to this, BSODs etc!

But what about this UDMA 6 versus 7?
https://dl.dropbox.com/u/4019461/C-Info-HDTune.jpg

That's the same thing - "UDMA7" would be enabled by going to AHCI and
running the SATA native instead of IDE emulation mode.

Cheers - Jaimie

 

[Mike Tomlinson]

Something dedicated to being a SMART reader might do a better job of
revealing the actual results!

It seems to be a bit of a black art, judging by posts in comp.sys.ibm.pc
..hardware.storage over the years. In addition, Seagate SMART data is
presented in a non-standard way so is even more hard to interpret.

 

[Mike Tomlinson]

Thanks Mike. I'm not brave enough to make that mode change, especially
after reading further about XP sensitivity to this, BSODs etc!

I might give it a go if feeling brave enough one day.

But what about this UDMA 6 versus 7?
https://dl.dropbox.com/u/4019461/C-Info-HDTune.jpg

It's probably because you're in IDE mode, if you got AHCI working you
might find HDTune showed both Supported and Active as UDMA7.

For what it's worth, HDTune shows my two SATA3 SSDs and one SATA2 HD as
running in UDMA mode 5 (Ultra ATA/100), but another utility, SIW,
correctly identifies the SSDs as SATA-600 (aka SATA3) and the hard drive
as SATA-300 (aka SATA2). Benchmarking with another utility (ASD SSD
Benchmark) confirms that.

I don't think you can rely on HD Tune to get it right here, especially
as it reckons my two SATA3 devices are SATA2. It's quite an old piece
of software now.

 

[Mike Tomlinson]

For what it's worth, HDTune shows my two SATA3 SSDs and one SATA2 HD as
running in UDMA mode 5 (Ultra ATA/100), but another utility, SIW,
correctly identifies the SSDs as SATA-600 (aka SATA3) and the hard drive
as SATA-300 (aka SATA2). Benchmarking with another utility (ASD SSD
Benchmark) confirms that.

Just to clarify the above (I hope!): HDTach is getting its information
at the software layer (from the device driver), which, because the
controller is set to IDE mode in the BIOS, is operating the disks as if
they were IDE devices, and ATA/133 is the fastest IDE access mode
possible.

SIW looks at the actual hardware and is able to determine that the
physical controller and drive are SATA.

 

[Rod Speed]

It seems to be a bit of a black art, judging by posts in comp.sys.ibm.pc
.hardware.storage over the years. In addition, Seagate SMART data is
presented in a non-standard way so is even more hard to interpret.

But the better SMART readers do allow for that last.

 

[Franc Zabkar]

I have two identical 750 GB Samsung HDs on this Quad Core 2.66 GHz, 4 GB
RAM PC, under Win XP.

C: Benchmark
https://dl.dropbox.com/u/4019461/C-Bench-HDTune.jpg

I: Benchmark for comparison
https://dl.dropbox.com/u/4019461/I-Bench-HDTune.jpg

C: Info
https://dl.dropbox.com/u/4019461/C-Info-HDTune.jpg

C: Health
https://dl.dropbox.com/u/4019461/C-Health-HDTune.jpg

Error Scans
Both C: and I: (and both external drives) gave no errors, solid green
display.

Q1 If C: is indeed considered by the experts to be performing abnormally
badly, what can be the explanation? And what if anything can be done?
(Note: Last night I set chkdsk C: /f, rebooted and went to bed. I did the
test shortly after getting back to my PC this morning.)

Q2 Why do transfer rates drop during the test, especially C:?

Q3 Why do the access times for C: vary so much?

Q4 Are the temperatures OK?

The dips in the transfer rate may correspond to interference from
background Windows tasks. Otherwise there may be "slow" sectors, ie
ones that require several retries. Each retry would require an
additional revolution of the platters. That would account for the
scatter in the access time graph.

You could run MHDD in DOS mode. MHDD will scan the surface and
identify the slow sectors, ie those that require more than 500ms.

The temperatures are good. In fact the temperature attributes are
better referred to as "Temperature Difference From 100". Therefore a
normalised value of 71 corresponds to 29C (= 100 - 71).

The raw values for the temperature attributes consist of several bytes
corresponding to the current, maximum and minimum temperatures for the
current power cycle. As such, the raw values are best viewed in
hexadecimal mode.

For example, if the raw value of attribute C2 were 555352093, then
this would equate to 0x0000211A001D in hexadecimal. This gives us
three temperatures, namely 0x21 (= 33C), 0x1A (= 26C), and 0x1D (=
29C).

As for the performance, it appears that the slow drive has three 250GB
platters and 6 heads whereas the fast drive has two 500GB platters and
3 heads. Normally a fully stroked 3.5" drive would have a 2:1 ratio
between the transfer rates at the outermost and innermost zones. In
the case of the slow drive, the max/min rates are about 90/45 MB/s.
However, in the case of the faster drive, the rates would normally be
127MB/s max and 63.5MB/s min.

IME the rule of thumb for transfer rates and data densities appears to
be ...

(data rate A) / (data rate B) = sqrt (density A / density B)

So ...

(127MB/s) / (90MB/s) = 1.411

.... and ...

sqrt(500GB / 250GB) = 1.414

The reason that the fast drive has a plateau at the beginning of the
benchmark graph is that it is being throttled by the SATA interface.
Other people have suggested that the SATA controller may be emulating
IDE mode. Could it be that the drives are connected to different SATA
controllers? For example, some motherboards have both Intel and
Marvell controllers.

- Franc Zabkar

 

[Terry Pinnell]

That's the same thing - "UDMA7" would be enabled by going to AHCI and
running the SATA native instead of IDE emulation mode.

Cheers - Jaimie

Thanks, understood.

 

[Terry Pinnell]

I might give it a go if feeling brave enough one day.


It's probably because you're in IDE mode, if you got AHCI working you
might find HDTune showed both Supported and Active as UDMA7.

For what it's worth, HDTune shows my two SATA3 SSDs and one SATA2 HD as
running in UDMA mode 5 (Ultra ATA/100), but another utility, SIW,
correctly identifies the SSDs as SATA-600 (aka SATA3) and the hard drive
as SATA-300 (aka SATA2). Benchmarking with another utility (ASD SSD
Benchmark) confirms that.

I don't think you can rely on HD Tune to get it right here, especially
as it reckons my two SATA3 devices are SATA2. It's quite an old piece
of software now.

I'm sure you're right. But it's handy nevertheless, especially when you
have a couple of identical drives as I do so that RELATIVE performance can
be measured. (But from Franc's post, maybe they're not identical after
all!)