Very Computer

For a database application, I am wondering what is the
theoretical maximum number of megabytes per second that could be
moved off a system disk of an external drive and moved into
memory of a top-line Wintel server.

Assume you had the following configuration:

- four fibre channel controllers in the server
- each controller is connected to a single logical drive, based
on an external RAID controller that stripes a huge disk array
- each controller is moving data to the host at 100 megabytes per
second
- the host stripes the four logical drives on the four
controllers, as a single RAID 0 drive (protection in this case
comes from the RAID5 stripe in the external controllers)
- theoretically, there could be 400 megs moving toward the host
at peak load
- the host is a Compaq ProLiant 7000 with 4 gigs of memory and
four Xeon 500 CPUs

Given the current limitations of the PCI bus, what is the maximum
amount of data that the system could receive?

--
Will
Internet: westes at uscsw.com

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Quote:>Given the current limitations of the PCI bus, what is the maximum
>amount of data that the system could receive?

At TechEd in Dallas last month Carl Tierney of UNISYS gave an
excellent presentation that dealt with the very types questions you
bring up.  I checked the slides and my notes and did not come up with
specific numbers, though I believe he did quote actual numbers.  He

might want to contact him directly.  Likewise the system he discussed
can be visited at www.unisys.com/sql7 for whatever that may be worth.
You should be able to get the slides for session 5-305 at:

http://www.teched99.com/slides.asp

Roy

Sorry about that.

Roy

Hi

Actually depends on the PCI slots in your server. Even Compaq ProLiant 7000
is not enough, because it depends on the board revision.
There are 3 PCI standards. First three are available in Compaq Servers, the
last will be...:
PCI 2.0, 33MHz, 32-bit, 132MB/s peak
PCI 2.1, 66MHz, 32-bit, 264MB/s peak
PCI 2.2, 66MHz, 64-bit, 528MB/s peak
PCI-X, 133MHz, 64-bit, 1056MB/s peak (not available, future project)

Usually there are at least 2 x PCI 2.2 and 4 PCI 2.1 slots in Compaq
Proliant 5500 and above. Usually...

Vassil Velichkov
Gramma

Quote:> For a database application, I am wondering what is the
> theoretical maximum number of megabytes per second that could be
> moved off a system disk of an external drive and moved into
> memory of a top-line Wintel server.

> Assume you had the following configuration:

> - four fibre channel controllers in the server
> - each controller is connected to a single logical drive, based
> on an external RAID controller that stripes a huge disk array
> - each controller is moving data to the host at 100 megabytes per
> second
> - the host stripes the four logical drives on the four
> controllers, as a single RAID 0 drive (protection in this case
> comes from the RAID5 stripe in the external controllers)
> - theoretically, there could be 400 megs moving toward the host
> at peak load
> - the host is a Compaq ProLiant 7000 with 4 gigs of memory and
> four Xeon 500 CPUs

> Given the current limitations of the PCI bus, what is the maximum
> amount of data that the system could receive?

> --
> Will
> Internet: westes at uscsw.com

> PLEASE READ:  To send me Internet e-mail, you must change the
> userid
> on this message from the word 'junkmail' to the word 'westes'.
> If you reply
> to the default address then I will not get the message!!

Check your Compaq specs on each server...I think that you are a little
off...PCI 2.1 and 2.2 only became available with the new 8 way Xeon
8000/8500's.  Prior to that PCI 2.0 was supported across the board.  Keep in
mind that this PCI support is a function of the Intel chipset, not a Compaq
board rev...

Regardless...the PCI bus is not the bottleneck, when a bus master FC card
arbitrates for the PCI bus, he gets full 133MB/s bandwidth, since only one
device can use the bus at a time there is no problem supporting 4 FC cards.
They each get their turn...

JH