What's the best way to connect harddrive to motherboard

[Jan]

Hi,

I hope somebody can help me in this matter....

I have the following two harddrives:
- Western Digital -> 80 GB - ATA100
- Maxtor -> 160 GB - ATA133

and I just got the motherboard MSI 865PE Neo2-FIS2R.

The board has the regular two IDE connectors and in addition the IDE3
which runs under the Promise Chipset. The IDE3 connector is a UDMA 133
controller.

So I hooked up both harddrives to IDE3, but the harddrive performance
was less than hooking the drives up to IDE1 (as per HDTach).
Can anybody explain why ?

The drives were connected to IDE1 with master/slave.

On the IDE3 connector I had to use RAID (don't know why), optimized
for performance.

Still, the transfer rate was (only) about 60 MB/s (average) for both.

Am I doing anything wrong ?
How can I get transfer rates over 100 MB/s ?

Any help is greatly appriacted....
Thanks
-DA

 

[kony]

Hi,

I hope somebody can help me in this matter....

I have the following two harddrives:
- Western Digital -> 80 GB - ATA100
- Maxtor -> 160 GB - ATA133

and I just got the motherboard MSI 865PE Neo2-FIS2R.

The board has the regular two IDE connectors and in addition the IDE3
which runs under the Promise Chipset. The IDE3 connector is a UDMA 133
controller.

So I hooked up both harddrives to IDE3, but the harddrive performance
was less than hooking the drives up to IDE1 (as per HDTach).
Can anybody explain why ?

Because the Promise chip resides on the PCI bus, a bottleneck, while
the chipset IDE, doesn't. So, even if you could get over 100MB/s
second from the drives, that's not always a good thing, because during
that period, you'd be leaving less than 33MB/s to ALL the other PCI
devices. The PCI bus is a huge bottleneck these days, but soon that
will change (PCI-X).

I'd leave the drives on the motherboard chipset IDE channels, and do
some searching around the 'net to see if anyone has hacked a bios for
that to enable the Promise chip to function as a regular UDMA
controller, which makes it useful for optical drives.

The drives were connected to IDE1 with master/slave.

On the IDE3 connector I had to use RAID (don't know why), optimized
for performance.

You could define each drive as a single stripe or span if you don't
want them RAIDed... preferribly as a span, because a span can be moved
to another controller someday, or the chipset IDE, while a stripe
can't, is bound to that Promise chipset, and possibly even that
motherboard.

Still, the transfer rate was (only) about 60 MB/s (average) for both.

Am I doing anything wrong ?
How can I get transfer rates over 100 MB/s ?

The easiest way is RAIDed SATA drives, running from an SATA controller
integrated into a southbridge.

For what you have, 60MB/s isn't all that bad... some people do get
lower with similar drives.

 

[Mike Walsh]

Because the Promise chip resides on the PCI bus, a bottleneck, while
the chipset IDE, doesn't.

All parallel IDE ports reside on the PCI bus. SATA connects to the system bus without going through the PCI bus.

So, even if you could get over 100MB/s
second from the drives, that's not always a good thing, because during
that period, you'd be leaving less than 33MB/s to ALL the other PCI
devices.

A standard PCI bus is 33 Mhz x 32 bits = 133 MB/sec

The PCI bus is a huge bottleneck these days, but soon that
will change (PCI-X).

PCI-X has been around for awhile, mostly used for SCSI adapters on server boards. I don't expect to see PCI-X on consumer boards since there is AGP for video and SATA for hard drives.

 

[kony]

All parallel IDE ports reside on the PCI bus. SATA connects to the system bus without going through the PCI bus.

No, all parallel don't. No modern chipsets (or the last few
generations) have placed the IDE controller on the PCI bus. SATA is
no different, if it's a separate chip providing the function, it's on
the PCI bus, but if integrated into the southbridge, it avoids the PCI
bus just as PATA does.

Here's a block diagram of the OP's chipset, i865PE:
http://www.zenha.net/hardware/2003_05/1/865pe.gif
Note the separate connection for PCI bus.

....or a Via 8237 southbridge
http://www.via.com.tw/en/images/Products/ApolloChipsets/vt8237_blkdiagram_L.jpg

A standard PCI bus is 33 Mhz x 32 bits = 133 MB/sec

Yes, theoretically. Note what I wrote, that if he gets over 100MB/s,
during that period of time, how much theoretical is left (even though
theoretical > actual)?
133 - 100 = 33
However much one PCI device uses, is taken away from the other PCI
devices for that period of time.

PCI-X has been around for awhile, mostly used for SCSI adapters on server boards. I don't expect to see PCI-X on consumer boards since there is AGP for video and SATA for hard drives.

Fair enough, I meant PCI-Express, soon to be released boards, chipsets
by Intel & Via.