Sata II speeds and botlenecks?

[Guest]

Is there any reason to go to the trouble to make sure my 750 Samsung
and seagate Hds are enabled for for Sata II speeds?

From what i've read so far you may have problems with some
motherboards and only a RAID would get anywhere NEAR needing that
speed. (of sata II).

My Hds are only listed as moving data at about 100 MB/second.

I do move and encode Gigs of video.

I just built my Quad 9450 -2600Mhz and it processes data at 49+
meg/second.with 78% cpu use. (dvd shrink-analyze option)

My old AMD 4200 X2 @ 2600Mhz only does 18 meg/second and 100% cpu use.

Looks like I'm not cpu bound anymore but
my new Hds should be able to move data faster then 49meg/second ???

On a straight Hd to Hd transfer a Gig will take maybe 12 seconds.

Wonder what my new bottleneck is.

Thanks,
jmc

 

[Arno Wagner]

Is there any reason to go to the trouble to make sure my 750 Samsung
and seagate Hds are enabled for for Sata II speeds?

Not really.

From what i've read so far you may have problems with some
motherboards and only a RAID would get anywhere NEAR needing that
speed. (of sata II).

If each disk gets its own channel (typical situation),
RADI is not an issue. The issue is if you start using a
port-multiplier and connect several HDDs over one
SATA channel. I am aware of one "box-type" RAID
sollution that contains a port multiplier and attaches
to a normal controller.

My Hds are only listed as moving data at about 100 MB/second.
I do move and encode Gigs of video.

I just built my Quad 9450 -2600Mhz and it processes data at 49+
meg/second.with 78% cpu use. (dvd shrink-analyze option)

My old AMD 4200 X2 @ 2600Mhz only does 18 meg/second and 100% cpu use.

Looks like I'm not cpu bound anymore but
my new Hds should be able to move data faster then 49meg/second ???

Depends. One possibility is that your filesystem is relatively
slow. Another is that you have to little memory left for
good buffering and write reordering and stuff has to be
flushed to disk prematurely.

On a straight Hd to Hd transfer a Gig will take maybe 12 seconds.

Wonder what my new bottleneck is.

First guess: Too little memory. Second guess, suboptimal filesystem
for the application. For the memory, check how much the OS
has left. I would say at these speeds 1GB left for the system
is needed for optimal performance, but that is just my WAG
for Linux. I doubt it can be done with significantly less, but it
may need more.

There is also a different possibility: Are you reading from that
disk at the same time? Even small reads can degrade performance
significantly. If you do large reads, then they also count as
accesses ;-)

One think is pretty sure: The bottleneck is not the SATA
buses.

Arno

 

[Rod Speed]

Is there any reason to go to the trouble to make sure my 750
Samsung and seagate Hds are enabled for for Sata II speeds?

Nope, it should do that auto.

From what i've read so far you may have problems with some motherboards
and only a RAID would get anywhere NEAR needing that speed. (of sata II).

Even that doesnt with current hard drives.

My Hds are only listed as moving data at about 100 MB/second.

Thats about all the physical detail of the drives allow, sector per track and RPM.

I do move and encode Gigs of video.

The encoding wont be limited by the hard drive speeds.

I just built my Quad 9450 -2600Mhz and it processes data at
49+ meg/second.with 78% cpu use. (dvd shrink-analyze option)

My old AMD 4200 X2 @ 2600Mhz only does 18 meg/second and 100% cpu use.

Looks like I'm not cpu bound anymore

You are likely to be limited by the ram interface speed now.

but my new Hds should be able to move data faster then 49meg/second ???

They arent what limits that particular speed.

On a straight Hd to Hd transfer a Gig will take maybe 12 seconds.

Wonder what my new bottleneck is.

Between the cpu and ram.

 

[Guest]

Not really.


If each disk gets its own channel (typical situation),
RADI is not an issue. The issue is if you start using a
port-multiplier and connect several HDDs over one
SATA channel. I am aware of one "box-type" RAID
sollution that contains a port multiplier and attaches
to a normal controller.





Depends. One possibility is that your filesystem is relatively
slow. Another is that you have to little memory left for
good buffering and write reordering and stuff has to be
flushed to disk prematurely.



First guess: Too little memory. Second guess, suboptimal filesystem
for the application. For the memory, check how much the OS
has left. I would say at these speeds 1GB left for the system
is needed for optimal performance, but that is just my WAG
for Linux. I doubt it can be done with significantly less, but it
may need more.

There is also a different possibility: Are you reading from that
disk at the same time? Even small reads can degrade performance
significantly. If you do large reads, then they also count as
accesses ;-)

One think is pretty sure: The bottleneck is not the SATA
buses.

Arno

Hmm, you have given me things to try...
I do only have one 2 gig ram stick in right now. (keeping testing
simple)
Will stick in my other 2 gig stick which will also give me "dual
channel" data path.

later I will test overclocking my RAM (suppose to be able to do 1066
speeds) and or CPU to see which makes how much dfference.
My CPU (2.66GHz) should be able to reach 3.6. But I won't be
trying that till I get a feel on how stable everying runs with stock
speeds.

Now that you mention it, I was testing on a partition that was on my
OS Hd. Will retest on a seperate Hd to reduce chance of the Hd trying
to do two things at once.....

I once thought that 100 meg/sec hd speed would be more then able to
easily feed several dvd burners.... What a joke! Even trying to feed
two burners off of one Hd completely killed performance.
Now I make SURE that it is "one Hd to one burner" only!

The file system is NTFS with 64K clusters. (defraged)
I was thinking big files would be better suited to BIG clusters.
BUT have never tested this.

I keep hoping to see SMALL high speed solid state drives...
(the ones I might be able to afford). Just for my OS drive 4-8 gig-
RAID 0.
The multi thousand $ SSDs they can keep.
Maybe some day.

Thanks very much for everone's thoughts!!
jmc