[Leaplist] The state of 3Ware/AMCC/LSI and Areca/ATTO hardware RAID -- WAS: New machine build ....

[Bryan J. Smith]

Kevin Korb <kmk at sanitarium.net> wrote:
> Actually, if you are going to buy a hardware RAID
> controller the Areca cards are much better than 3Ware
> these days.  The drivers are better too.

Depends on the 3Ware (AMCC, now LSI) card.

There are also long-term support issues with Areca (now ATTO),
as Intel abandoned their microcontroller choice in 2006 (selling
to Marvell).

3Ware products through 9500S are an aged ASIC design.  Sure, they can
fling a 64-bit datapath through directly switched interconnects and
store/retrieve from SRAM (that's Static RAM, not SDRAM) without any
wait state.  But they aren't going to handle I/O requests well, and
especially not when it comes to buffering RAID-5 operations -- not
even the 9500S with added SDRAM.

AMCC then bought IBM's PowerPC 400 line, and the 3Ware products have
gone through several revisions from the 9550SX to 9650SE to the latest
9690SA.  AMCC bought 3Ware awhile back (although LSI just bought AMCC).
The 9550SX had some bumps, but the 9650SE/9690SA products are solid.
The PPC400 microcontroller paired with 3Ware's ASIC is a very, very
well supported product in Linux via the 3w-9xxx driver.

Areca was the first to exploit Intel's new X-Scale (former ARM /
Digital StrongARM) microcontroller in what would become the 2nd
gen of the IOP300 series.  The early IOP30x products were Intel i960
and a total slouch for RAID even a decade ago (not capable of 50MBps).
Areca increasingly developed mature Linux drivers, although a lot of
focus (at least in the large port cards) was to offer a management
console directly into the card (an ingenious idea).  When 3Ware was
still trying to just add SDRAM to its aging ASIC in the 9500S, and
even with its early 9550SX PPC400 designs, Areca was clearly better.

Unfortunately, Intel sold its X-Scale line to Marvell in 2006.  We
know all know it was Atom that Intel replaced it with (although Atom
in the embedded area is still maturing).  I know the Areca 3Gbps
SATA/SAS line is a Marvell IOP340, and it is comparable with the
PPC400 in the newer 3Ware lines.  Although I'm under NDA with
Timesys with many aspects regarding Intel, I can publicly mention
that customers would regularly complain about lack of Intel support.

And that was back in 2007.
 
I don't know Areca's new 6Gbps SAS line uses, although it's likely a
Power derivative like AMCC/3Ware.  I.e., ATTO uses a lot of Motorola/
Freescale, and I've seen PowerQIC used on their various storage products.
It would only seem natural that they too drop Intel, now Marvell, and
move to something else -- although I have not confirmed that.

Understand there is a great amount of convergence these days with
storage.  Both FibreChannel (FC) and Serial Attached SCSI (SAS) are
SCSI-2 over interconnects of multi-GHz signaling now.  Both FC and
SAS are multi-targettable and distributed (whereas SATA is without
the SCSI-2 stack and only point-to-point, let alone only 1m, 2m
if you believe the eSATA marketing, whereas SAS is 8m).

So the performance aspect these days is really almost even.  The
support aspect is always the question.

3Ware always supported Linux to the hilt.  Don't know if that will
always be the case as the LSI Logic purchase of AMCC may result in a
split hardware-software model with their MPT Fusion marketing.  I.e.,
LSI Logic's MPT Fusion is about selling you hardware with a base 
software RAID management stack, and then squeezing out more money to
support various RAID management options.  But for now, the current
and existing 3Ware products are PPC400-centric.

Areca, thanx to Intel, made good on Linux support.  Now that Areca
is dealing with Marvell and/or leveraging ATTO's typical designs (seemingly Power), I'm now more conerned as well.  In the case of
their 3GHz SATA/SAS models, it's the late IOP340 that Marvell now
inherits, so it should be as supported as before.  Don't know about
the new 6Gbps models.


-- 
Bryan J Smith          Professional, Technical Annoyance
b.j.smith at ieee.org    http://www.linkedin.com/in/bjsmith
--------------------------------------------------------
I don't have a "favorite Linux distro."  I use, develop
and support community efforts, often built around Linux.
Technology and solutions are my focus, not dragging in
assumptions, marketing and other concepts which dominate
non-community developed software, which I left long ago.



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