Our colleague at www.pcper.com -- Allyn Malventano -- asked the following question:
> Are you proposing an independent head RAID-within-a-drive?
Our answer follows:
No ... just a simple & low-cost RAID 0 that can exceed 300 MB per second using just 2 x rotating HDDs, and each HDD has a relatively large hardware cache, even though each rotates at only 7,200 rpm.
The WD2503ABYX also has a 5-year factory warranty and this experiment configures 2 of those in a single RAID 0, with XP/Pro SP3 installed in a 30GB "short-stroked" system partition.
(Compare 3- and 5-year warranties by dividing retail cost by warranty years:
the 5-year "enterprise" warranties usually come out ahead on this measure.)
All ATTO measurements are being done on that short-stroked C: partition.
The ASRock G41M-S3 motherboard is another way to save money:
the single x16 slot is only Gen1, but it still has plenty of bandwidth for this experiment.
According to the specs I've found on the Internet, that motherboard has a Gen1 x16 slot and a Gen2 x1 slot: this is a feature of the G41 chipset.
(If upgraded video is required, there is that Gen2 x1 slot for compatible video cards:
Newegg has quite a few x1 video cards, some with support for 2 monitors;
nevertheless, for applications such as an inexpensive storage server,
the integrated graphics are just fine; and there are 2 x PCI slots,
one of which can host a Gigabit NIC.)
And, DDR3 memory is also very inexpensive now:
this machine has a matched pair of Corsair XMS3 DDR3-1333.
I think I paid only $120 for that motherboard + memory + one LG IDE optical drive.
Today, I updated the driver in my used Highpoint RocketRAID 2322:
and was able to break through 300 MBps here with those 2 x WD2503ABYX:
Next step is to replace that older controller with a slightly more expensive RocketRAID 2720SGL
which is on order and should arrive in about one week:
(I'd also like to see Highpoint offer the RR2710 in a "SGL" variant:
because only 4 such 6G SATA/SAS channels are all that may be needed for the SOHO settings I'm contemplating i.e. much higher densities per HDD, soon to exceed 3TB per drive using Hitachi's latest announcement of 1TB per platter)
I know you do prefer much better RAID cards, but the experiment here is to deliver decent performance on a very restrained budget e.g. typical of SOHO settings -- in recognition of nationwide economic conditions.
I'll measure the effect of this upgraded controller, then I'll upgrade the OS to Windows 7 Ultimate 64-bit version and repeat the same measurement.
Finally, funds permitting, I can also upgrade that G41M-S3 motherboard to 1333 MHz front-side bus and DDR3-1333, for a 1:2 FSB : DRAM ratio (333:667); this change must be done with jumpers instead of BIOS settings. But, I'm expecting minimal effects from faster processors, because the Pentium 4 model 640 is already 3.2 GHz, and these experiments are I/O-bound.
One key objective of this experiment is to substantiate my proposal to Western Digital that they upgrade their 7,200 rpm RAID Edition HDDs with 6G support + relatively smaller capacities but with relatively larger caches e.g. 64 or even 128MB per HDD. In this way, a RAID 0 array effectively adds the caches for all such RAID members, and this "cumulative cache" can help to eliminate the need for a large hardware cache on-board the RAID card e.g. on Areca cards -- further reducing overall cost.
If you start reading this thread from the top-down, that proposal will make more sense.
I think there is no argument that enterprise-class storage remains very expensive e.g. 6G Velociraptors or 15,000 Hitachi 2.5" SAS HDDs, and thus remain mostly out of the reach of SOHO budgets:
I'd like to bring more powerful storage to SOHO settings, without the premiums which enterprises are willing to pay and SOHO budgets cannot afford.
Lastly, there is still too much uncertainty associated with SSDs, if my reading of recent industry reviews is representative of the current installed base of SSDs.
Many thanks for your interest, Allyn.
Cc: Ryan Shrout at www.pcper.com , and also hardocp.com
/s/ Paul A. Mitchell, B.A., M.S., Instructor,
Inventor and Systems Development Consultant
All Rights Reserved without Prejudice