[NTLUG:Discuss] RE: true hardware/intelligent ATA RAID -- XScale SATA RAID solutions arrive (including PCIe)

[Robert Pearson]

Bryan,

Let me first say "Thanks" for all the great information. I have a
concept I use I call the Speed Limit of the Information Universe. It
is really a table or map of the rate at which Information can move
from any point in the IT infrastructure to any other point. The most
critical points are key destination-source pairs like storage to user.
Another key sub-map is the server I/O map. It has always been very
difficult to get "lower metric" "speed" information without actually
setting up a test configuration and testing it.

I'm a little confused about all these bus types. In particular the
names and I/O rates. I did a little Googling and found the
following---

Older bus type standards such as ISA, EISA, PCI and PCI-X.
Newer bus type standards such as HyperTransport, PCI Express and RIO.
"Such as" usually means there are more bus type standards but these
are the most common or popular. I never heard of RIO. I once kept
track of Infiniband and all its competitors but that was 4-5 years ago
and these buses are just now making it to the marketplace. Infinband
appear to be dead.

This is the guy who was describing the bus types---

Brian Holden is a Principal Engineer in the Microprocessor Products
Division at PMC-Sierra, who involves in the development and
standardization of processor busses.
Mr. Holden is currently the Technical Chair of the HyperTransport
Consortium and serves on the board of the Network Processing Forum.

Bryan J. Smith wrote:
>  XScale-based SATA RAID solutions_are_ now available! 
> 
> - The I/O Processor Bottleneck Removed
> 
> - IOP331 (i80331) "Lindsay" 133MHz PCI-X 1.0 (1GBps)
> - IOP332 (i80332) "Dobson" 133MHz PCI-X w/8-channel PCI-Express bridge
> 
> Both are going to exceed the throughput capability of the older IOP30x
> series by 10-fold or greater.  This matches well to PCI-X 1.0
> slots of 66-133MHz.

This is very good news. Will future change be by orders of magnitude,
linearly, geometrically or we will just have to wait and see? Disk
capacities sort of doubled each time they increased.

> The LSI Logic MegaRAID SATA 300-8X is an 8-channel solution with the
> IOP331.  It has a fixed configuration of 128MB of DDR333 ECC SDRAM.
> Battery backup is an option.  Both SATA/150 and SATA2/300 (300MBps) are
> supported with the on-board controllers (one controller per 4 channels).
 
Did I read that right? 300 Megabytes per second?

> The TekRam solutions are similar...for PCI-Express (PCIe)...
> ...ATA drives are typically tested to lower tolerances for
> only 14x5 operation (not 24x7).

Good input. This means that PCI-Express is changing its name to PCle?
Do you believe I can achieve five nines "99999" of Information High
Availability with ATA RAID or FRAID? How much dispersion or how many
mirrors do I need to achieve that? Or does it take Xscale SATA RAID?
The Xscale SATA RAID performance at an ATA price would be very nice. I
have read that SATA drives are not as robust as ATA which surprised
me.
 
> I would love to see a review pitting these new XScale microprocessor +
> DDR-SDRAM "buffering" solutions versus 3Ware's ASIC + SRAM
> "non-blocking" solutions...

So would I. If you find one let us know and I will do the same.

> - Consumer PCIe Product?  What about boards with both PCI-X and PCIe?

Good idea. Which bus would support which functions?
=======================================================
||     Bus        ||       Function        || Required bandwidth ||
Total bandwidth ||
=======================================================
||    PCle        ||          ???            ||                       
       ||                        ||
-------------------------------------------------------------------------------------------------------------
||    PCI-X       ||          ???            ||                       
       ||                        ||
=======================================================

> I'm still hoping someone introduces a budget-conscience, but true
> hardware ATA RAID solution for PCIe x1 with 2-4 channels for sub-$250
>...  Since PCIe x1 will be commonplace in near-future mainboards...

Amen. I hope I live to see this. How many Megabytes per second would
you expect to see from this configuration?
 
> Another idea I had is a card that "flips" to offer both PCI-X and PCIe

How about we just bypass the bus all-together? Let's just use direct
optical links to the high speed destination-source pairs? We should be
able to design a mobo that allows that. Instead of having TOE bus
cards we have TOE chips in the set. Maybe we should think vertical on
mobo's?

Thanks,

Robert