SATA II PCI Card

R

Ryan

Hello,

I have a few questions. I recently purchased 2 SATA II harddrives for
my system which has a P4P800e motherboad. The SATA ports on the
motherboard are SATA I, and are both in use. I need to get a
controller card and a few in mind. 2 are for SATA I drives and 1 is
for a SATA II drive.

First, am I correct in understanding that the p4p800e only has 33MHZ
PCI slots.

Secondly, given the speed limitations of PCI, does it make any sense
for me to spend an additional $50 to get a the PROMISE SATA300 TX2plus
PCI SATA / IDE Controller Card or is it just a gimmick because my PCI
slot will just end up being a bottle neck anyway?

Thanks!
Ryan
 
P

Paul

Ryan said:
Hello,

I have a few questions. I recently purchased 2 SATA II harddrives for
my system which has a P4P800e motherboad. The SATA ports on the
motherboard are SATA I, and are both in use. I need to get a
controller card and a few in mind. 2 are for SATA I drives and 1 is
for a SATA II drive.

First, am I correct in understanding that the p4p800e only has 33MHZ
PCI slots.

Secondly, given the speed limitations of PCI, does it make any sense
for me to spend an additional $50 to get a the PROMISE SATA300 TX2plus
PCI SATA / IDE Controller Card or is it just a gimmick because my PCI
slot will just end up being a bottle neck anyway?

Thanks!
Ryan

Yes, the PCI bus is 33MHz. The bus will limit the performance of SATA
cards, either SATA I or SATA II. At least, if you are concentrating on
the "burst to controller cache" performance.

The sustained transfer rate of a disk, is in the vicinity of 60 to 70MB/sec,
in which case the PCI bus is still sufficient when you are transferring
1GB sized files. When transferring a big file, the media rate of the disk
is the limiting step. If you run two disks in RAID0, then the bus becomes
a limitation to the sustained transfer rate. But one disk fits OK.

The only time SATA I or SATA II bandwidth gets really used, is "burst to
controller cache". And in the grand scheme of things, that doesn't do much
for you.

What you want to research, is whether a particular controller has a
history of working well, or is known to corrupt data, or have
crappy drivers. With the limits of the PCI bus, I wouldn't waste a
lot of mental energy on the performance side of things. When you do
want, is good reliable performance, and a product you can trust with
your data.

Even the connectors can make a difference. The early SATA connectors
had no retention feature. But there are some cables now, that have a
metal thing to help retain the cable. The metal thing can only work,
if the SATA connector has a matching plastic feature, for the metal
to grip. So if both the cable and controller card have the latest
connector style, that will help keep the cables in place.

(Example of a latching cable.)
http://www.satacables.com/assets/images/latching-sata-II-data-signal-cable-latching.jpg

In terms of cable types, there are "right angle", "left angle", and
straight connectors, with and without retention feature. There are
also ESATA cables, with a different connector shape and metal shell,
and a higher allowed number of insertion and extraction cycles. For
a crappy connector, there sure are enough styles available.

http://www.satacables.com/index.html

Paul
 
R

Ryan

Yes, the PCI bus is 33MHz. The bus will limit the performance of SATA
cards, either SATA I or SATA II. At least, if you are concentrating on
the "burst to controller cache" performance.

The sustained transfer rate of a disk, is in the vicinity of 60 to 70MB/sec,
in which case the PCI bus is still sufficient when you are transferring
1GB sized files. When transferring a big file, the media rate of the disk
is the limiting step. If you run two disks in RAID0, then the bus becomes
a limitation to the sustained transfer rate. But one disk fits OK.

The only time SATA I or SATA II bandwidth gets really used, is "burst to
controller cache". And in the grand scheme of things, that doesn't do much
for you.

What you want to research, is whether a particular controller has a
history of working well, or is known to corrupt data, or have
crappy drivers. With the limits of the PCI bus, I wouldn't waste a
lot of mental energy on the performance side of things. When you do
want, is good reliable performance, and a product you can trust with
your data.

Even the connectors can make a difference. The early SATA connectors
had no retention feature. But there are some cables now, that have a
metal thing to help retain the cable. The metal thing can only work,
if the SATA connector has a matching plastic feature, for the metal
to grip. So if both the cable and controller card have the latest
connector style, that will help keep the cables in place.

(Example of a latching cable.)http://www.satacables.com/assets/images/latching-sata-II-data-signal-...

In terms of cable types, there are "right angle", "left angle", and
straight connectors, with and without retention feature. There are
also ESATA cables, with a different connector shape and metal shell,
and a higher allowed number of insertion and extraction cycles. For
a crappy connector, there sure are enough styles available.

http://www.satacables.com/index.html

Paul- Hide quoted text -

- Show quoted text -

Thanks Paul!

One last question, when a 32-bit card says 33/66MHz fully compliant
PCI host interface does this mean that it is actually capable of
running at 66MHZ (assuming it is placed in a PCI slot that can run at
66MHZ) or does it mean that it can be used in a 66MHZ PCI slot though
it will still actually run at 33MHZ? I guess what I am asking is if
all 32-bit cards run at 33MHZ, or whether a 32-bit card could run, as
in this instance, at 66MHZ.
 
M

Michael Hawes

Ryan said:
Thanks Paul!

One last question, when a 32-bit card says 33/66MHz fully compliant
PCI host interface does this mean that it is actually capable of
running at 66MHZ (assuming it is placed in a PCI slot that can run at
66MHZ)
Yes

or does it mean that it can be used in a 66MHZ PCI slot though
it will still actually run at 33MHZ? I guess what I am asking is if
all 32-bit cards run at 33MHZ, or whether a 32-bit card could run, as
in this instance, at 66MHZ.
In the real world, the difference between SATA150 & SATA300 is minute.
No production drive can read data at more than 150Mb/s, and the drive cache
is 16Mb Max, and that is the only data that can read off at the max speed of
the SATA interface. The difference in benchmarks will be small, in real
applications, will be too small to notice.

Mike
 
P

Paul

Ryan said:
Thanks Paul!

One last question, when a 32-bit card says 33/66MHz fully compliant
PCI host interface does this mean that it is actually capable of
running at 66MHZ (assuming it is placed in a PCI slot that can run at
66MHZ) or does it mean that it can be used in a 66MHZ PCI slot though
it will still actually run at 33MHZ? I guess what I am asking is if
all 32-bit cards run at 33MHZ, or whether a 32-bit card could run, as
in this instance, at 66MHZ.

A 66MHz capable bus segment, uses the M66EN signal. The PCI cards vote
on what they want to do. Your 33/66MHz storage card won't pull down
the M66EN signal. A 33MHz only card, will ground the M66EN signal.

What that does, is ensure if there are a mixture of 33MHz and 66MHz
cards, that the bus runs at 33MHz. If only 66MHz cards are present,
the M66EN signal floats high, and all the cards can see it and
rejoice.

The motherboard clock generator, sends out a clock signal, based on
the vote. If the clock generator sees M66EN = 1, then it'll put
the 66MHz clock out there.

A 33/66 card can run at either speed, and the speed used is determined
by the vote, and by the capabilities of the motherboard.

On a 33MHz only bus segment, nobody really cares what happens to the vote.
Because then, the motherboard isn't even remotely interested in the
state of the M66EN signal. In that case, there is only a 33MHz clock.

Paul
 
R

Ryan

A 66MHz capable bus segment, uses the M66EN signal. The PCI cards vote
on what they want to do. Your 33/66MHz storage card won't pull down
the M66EN signal. A 33MHz only card, will ground the M66EN signal.

What that does, is ensure if there are a mixture of 33MHz and 66MHz
cards, that the bus runs at 33MHz. If only 66MHz cards are present,
the M66EN signal floats high, and all the cards can see it and
rejoice.

The motherboard clock generator, sends out a clock signal, based on
the vote. If the clock generator sees M66EN = 1, then it'll put
the 66MHz clock out there.

A 33/66 card can run at either speed, and the speed used is determined
by the vote, and by the capabilities of the motherboard.

On a 33MHz only bus segment, nobody really cares what happens to the vote.
Because then, the motherboard isn't even remotely interested in the
state of the M66EN signal. In that case, there is only a 33MHz clock.

Paul

So if I were to plug the 33/66MHZ card into a motherboard that had
66MHZ slots, the card would be able to support faster data transfer
(from burst)? If price is negligable, would it then be worth
getting a 33/66 card over a 33 only, so that if I should I ever
upgrade my system the card would be a little less obsolete. I have
basically identified 2 cards. I only have a need at the moment for 2
SATA ports. However, there is a 33MHZ only card that also has a PATA
slot. I suppose it would not hurt to have that now, and I've also
noticed that a lot of newer motherboards are only coming with one PATA
slot, so I thought maybe it would not be bad to have in the future.
That said, because the card is only 33MHZ, I am thinking that I should
probably get the 33/66 just so, in the future, it could run in a 66MHZ
slot. I am assuming that motherboards will still support older PCI
cards but will all be 66MHZ. Not sure if that is a good assumption!

Thanks!
 
R

Ryan

In the real world, the difference between SATA150 & SATA300 is minute.
No production drive can read data at more than 150Mb/s, and the drive cache
is 16Mb Max, and that is the only data that can read off at the max speed of
the SATA interface. The difference in benchmarks will be small, in real
applications, will be too small to notice.

Mike- Hide quoted text -

- Show quoted text -

I had heard something like that, but did not quite understand when/how
often a drive could achieve burst speed until reading what you wrote.
It helps! Thanks! Between you both I feel confident I should go with
the SATA I controller, now its just a matter of which one!
 

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