On 03/09/09 10:37, Mark Walkom wrote:
I was thinking the same, but I reckon because they are just backing
up/archiving data it wouldn't be too bad.
ie They aren't looking for huge performance, just huge, cheap storage.
2009/9/3 Morgan Storey<m...@morganstorey.com>
I know I am a geek but that is hot.
I am wondering if they see any throughput issues with the sata backplanes
and pci sata cards.
The backplanes are probably fine, each sata cable is good for
~300mbytes/sec most physical disks couldn't hope to hit that.
lesse what their maximum xfer rate is.
each drive can hit 103mb/sec average (better than I thought)
each sata channel will max out at 250mbyte/sec
so they are going to be loosing some bandwidth there.
their backplanes take 5 disks, so a potential bandwidth of well call it
500mbyte/second
so 50% is out the window there actual bandwidth per 5 disks is going to
be 250mbyte
they have 9 of these channels for a total bandwith available of
2250mbyte/sec (2 gigabytes a second, that'll rip some dvds fast)
standard PCI tops out at 133mbyte/sec so thats out ;->
it looks like they are using PCI-E SATA cards
the mbo they have and the cards they are using indicate they have 3x of
something like this
http://www.syba.com/index.php?controller=Product&action=Info&Id=861
which maxes out at 250mbyte/sec per (1x PCI-E 1x lane)
and one 4 port card which if it comes from that mob must be a PCI by the
look of things.
but I'll assume that its PCI-E and at least 4 lanes.
so the total xfer rate is 1750mbyte/sec
(or 883 if they are using the PCI card)
Vs the total possible xfer rate of 4500
they aren't doing *too* badly
given that on a gigabit ethernet connection you are lucky to push
30mbyte/sec (or 60 if you tweak it), I think its not going to be a big
issue ;->
If they wanted more oomph their best bet would be to put 2x 16 port
PCI-E 16x cards into a motherboard that supported it (most decent SLI
motherboards will do that)
better still one with 4x pci-E 16 slots so that you can put some 10gigE
cards in as well something like
http://www.aria.co.uk/Products/Components/Motherboards/Socket+AM3+(AMD)/MSI+790FX-GD70+AM3+Motherboard+with+4+x+PCIe+x+16+?productId=36604
say (but with intel of course ;->)
That should net you (assuming you use dual port 10gig-E nics) an xfer
rate out of the box of around 2400mbytes/sec
almost fast enough to spy on teh entirez intarwebz!!
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