[dba-Tech] Petulant PC

Jim,

Yes, you can do that.  The raid 5 performance for the motherboards I was
using was abysmal, down around 5 mbytes / sec write and 40 mbytes / sec
read.  And these were recent motherboards at the time I selected them (ASUS
M2N32-SLI Deluxe).  

http://www.newegg.com/Product/Product.aspx?Item=N82E16813131011

With the dedicated raid controller with co-processor, the write speeds are
up around 50 mb / sec and reads are around 400 mbytes / sec.  It happens
that I am building a SQL Server machine specifically.  Thus the motherboard
native timings simply did not work for me.

I have another older machine which I set up to do the address validation
software.  I needed far higher speeds than was available at the motherboard
level, specifically for reading quite large (1.5 gb) data files.  I ended up
buying a "RAMDISK" board and installing 3 gb of old ram I had hanging
around.  That gave me about 120 mbytes / sec throughput, read or write (only
needed the read in this case).  That speedup made an almost direct 1 to 1
difference in my application's speed, i.e. it was disk read bound.  A normal
disk drive reads about 50-60 mbytes / sec.  The RAM disk doubled my
throughput.  Given that I am processing 50 and 100 gigabyte files, wringing
the last ounce of speed is necessary.

For simple backups however, a motherboard based solution is ok.  Notice that
I still don't endorse it simply because the MB becomes the weak link.  If it
dies for some reason, the raid array is trash unless you can get an
identical motherboard.  Once you move to a dedicated raid controller, if the
MB dies you can move the raid controller to another machine and be back up
and running fairly quickly.

John W. Colby
Colby Consulting
www.ColbyConsulting.com 
-----Original Message-----
From: dba-tech-bounces at databaseadvisors.com
[mailto:dba-tech-bounces at databaseadvisors.com] On Behalf Of Jim Lawrence
Sent: Monday, June 04, 2007 2:13 PM
To: 'Discussion of Hardware and Software issues'
Subject: Re: [dba-Tech] Petulant PC

Hi John:

Can you not just use the SATA controller off the motherboard? All the new
boards (GigaByte) come with at least 2 SATA connections. I have hooked up a
5 drive array off one connection and striped them and then added another 2
off the second connection for the OS drives, for a client. The mother board
minus the RAM came to $276.00CAN, 1.7GHz, LAN card, Video Card and Sound
Card built in plus RAID software. The performance, though not stellar is
quite acceptable.

That is a good price for the drives though.

Jim