[LUNI] experience with 3ware

[Rick Sullivan]

Martin Maney wrote:
> 
> On Thu, Mar 14, 2002 at 03:42:31AM -0600, Rick Sullivan wrote:
> > I experienced the same thing (88% cpu util with an Athlon MP 1600+ and
> > 512 MB RAM on NT4 SP6a) a couple of weeks ago on an Abit KG-7 RAID,
> > which has the HPT370 chip - RAID 10 with 2 IBM 60GX 40 MB drives. So
> > these are just general feelings, and thruput was not measured. The
> > thruput of the IBM 60 GX drives is no more than a current 10K RPM SCSI,
> > which is what the first test was compared against (I think
> > StorageReview,com had an article about this in the last 6 months), so I
> > would expect CPU util would be somewhat closer to the 15% of SCSI. One
> 
> If I understand you, there wasn't anything the same, so the CPU usage
> figures are bascially meaningless.  Not that I actually doubt that the IDE
> solution might not use more of the CPU than the much more expensive SCSI
> RAID controller, but between the apples on one side and watermelons on the
> other, well, it's just not a very useful guide, is it?
> 


My basic premise is that IDE RAID controllers appear to need a lot more
CPU power than even modest SCSI drives when doing a lot of disk I/O.

All systems have Matrox G400 or G450 video cards, so I am presuming that
the Diskeeper GUI has a negligable affect on CPU utilization.

Note the last 2 systems are nearly identical, except for the
controller/drive(s).


The SCSI Reference system:

Intel L440GX+ w/ 2 x Pentium III 450's
1 GB RAM
Onboard Adaptec 2940u2w
another plug in Adaptec 2940u2w
Quantum Cheetah 10K drives
WinNT 4 Server SP6a SOFTWARE RAID 1  (These are NOT hardware RAID
controllers)


The 3ware system:

Intel SE440BX-2 w/ Pentium III 450
512MB RAM
2 x Adaptec 2940 w/ 2x Quantum Atlas III in software RAID 1
(boot/system)
3ware Escalade 6800 w/4 Quantum 80GB (5400RPM) in RAID 10 (LOTS of data)
WinNT 4 Server SP6a


The HPT370 system:

Abit KG-7 RAID w/ AMD Athlon XP 1600+
512 MB RAM
onboard HPT370 IDE RAID w/ 2 x IBM 60GX 40GB 7200 RPM drives in RAID 1
Latest mobo BIOS (68) and HPT370 firmware (2.1)
WinNT 4 Server SP6a


My Box:

Abit KG-7 Lite w/ AMD Athlon XP 1600+
512MB RAM
Adaptec 26160 w/ 1 x Seagate Barracuda (7200 RPM)
WinNT 4 Workstation SP6a


Informal observation running Diskeeper 4.5, a Win NT disk defragger:


System		Controller/Drive tesed			Typ. CPU util
---------	------------------------------------	-------------

SCSI Ref.	2940u2w/Cheetah Software RAID 1		< 15%

3ware		Escalade 6800 IDE Hardware RAID 10	~ 90%

HPT 370		HPT370 IDE Hardware RAID 1		~ 88%

My Box		29160/Barracuda single drive		< 20%


I guess I see some kind of pattern here, even taking into consideration
the apples/oranges/waterlemons of the systems tested.


> > more complicating factor is the 3Ware is a much better RAID controller
> > than the HPT370.
> 
> I may be wrong, but I thought the HPT was one of those currently popular
> "Win-RAID" chipsets - not really hardware RAID, just a UDMA controller
> that's bundled with (Windows) software RAID.
> 

The HPT 370 has a BIOS just like a SCSI controller, and the RAID setup
is done here - spanning, formatting and mirroring, so I don't think the
RAID activity happens thru o/s software.

Whatever HPT370 is, it theoritically works with Linux:
http://www.highpoint-tech.com/370drivers_down.htm

1/2 way down


A useful site if you have a KG7/KR7 and do Windoze:
http://www.viahardware.com/faq/kg7kr7/kg7kr7faq.htm