What's the fastest HD setup?

[J. Clarke]

The old x86 servers found on ebay will use PAE to address memory above
4GB and a copy of x86 WIndows/Server will make that memory available.

Each and every process on this machine will only be 4GB maximum and
context switching is used by sophicticated application software
(Oracle and maybe MS SQLServer that I know of) to simulate larger
adresses with as little performance penalty as possible.

The OP should look at an AMD64 or opteron mobo and a native 64bit OS.

You might pick up a small Sparc server on Ebay and run Linux on
it. The Sparc chip has been 64 bits to many years. I/O speeds
will scream on the SCSI disks and busses.

Al, ia64 is _not_ x86 in any way, shape, or form. The DL590/64 is an ia64
Itanium box, socketed for four processors and a huge amount of RAM, with
numerous PCI-X slots, not an "old x86 server". The price for the whole box
with two processors, a couple of SCSI drives installed, and a gig of RAM is
about the same as you pay for the cheapest AMD64 board that is socketed for
more than 4 gig of RAM and the cheapest processor that will fit it.

If your objective is to use the thing as a solid-state disk the old Itanic
seems like a bargain.

 

[Al Dykes]

Al, ia64 is _not_ x86 in any way, shape, or form. The DL590/64 is an ia64
Itanium box, socketed for four processors and a huge amount of RAM, with
numerous PCI-X slots, not an "old x86 server". The price for the whole box
with two processors, a couple of SCSI drives installed, and a gig of RAM is
about the same as you pay for the cheapest AMD64 board that is socketed for
more than 4 gig of RAM and the cheapest processor that will fit it.

If your objective is to use the thing as a solid-state disk the old Itanic
seems like a bargain.

I'm familiar with ia64 in general but never looked at any hardware and
missed the point of tthe DL590 reference. A bit of brain fade on my
part.

I just looked at a one on ebay. neat but I'd go with a sparc box.
Much much more hacker support and spares. Of course that means it
goes for more on ebay.

 

[Folkert Rienstra]

That is overly simplified. You'll probably need 4 to 5 IOs for that
and have to wait for each one of them to finish except for using SCSI.


Well, that is RAID.


For what you are proposing it is hugely over the top.

PCI-X can be 64-bit as well as 32-bit, similar to regualar PCI (without the -X).

 

[Folkert Rienstra]

Probably not.

These are the maximum rates:

You left out a few.

32bit PCI, 33MHz - 133MB/s

64bit PCI, 33MHz - 266MB/s

(usually SCSI)

32-bit PCI, 66MHz - 266MB/s, (usually ATA).

64bit PCI, 66MHz - 532MB/s

32-bit PCI-x, 66MHz - 266MB/s
64-bit PCI-x, 66MHz - 532MB/s

64bit PCI-X, 100MHz - 800MB/s
64bit PCI-X, 133MHz - 1GB/s

32-bit etc. etc. etc.

And then there is PCI-X v2.0

 

[Folkert Rienstra]

Even PC100 memory was good for 400 MB/sec. The bandwidth of the memory in
modern machines is measured in gigabytes/sec, not mega. You don't need
dual channel or dual ported or dual anything else to handle 15 MB/sec.

Nope, but OP needs the processor in that timeframe and that timeframe is therefor
not available for DMA.
One way of solving the 8ms/65MBps bottleneck might be to shorten the 25ms
timeframe by going to a faster processor but I think he has already explored that.

 

[J. Clarke]

I'm familiar with ia64 in general but never looked at any hardware and
missed the point of tthe DL590 reference. A bit of brain fade on my
part.

I just looked at a one on ebay. neat but I'd go with a sparc box.
Much much more hacker support and spares. Of course that means it
goes for more on ebay.

Can't disagree with that. An Alpha would probably do the job as well.

 

[Eric Gisin]

All versions since Win2K have the /PAE boot.ini switch, which gives you 36 bit
CPU addressing and 64 bit PCI addressing (from kernel mode). Desktop versions
of the OS will not use memory beyond 4GB, but the PAE kernel is still included.

Windows XP 64-bit edition for Itanium directly addresses 16 GB of RAM. If
you can find a copy. It won't be cheap. The 4 GB limitation is for 32-bit
Windows. 32 bit Windows will not run on an Itanium.

You don't need it. Google PAE ram-disk. They run on Win 2K/XP Pro.

 

[J. Franchino]

Thanks everyone. It has been overwhelming reading all of the
suggestions. This is just what I wanted: a ton of ideas. The nice
thing is, there's more than one way to skin a cat. I'm sure most of
your suggestions would work. Here's what I ended up doing that fixed
my problem. I'm a reasonable hardware-savvy guy, and I didn't think
this would solve it, but I tried it anyways and it worked:

All my measurements made it look like the bottleneck was in writing the
stuff to disk. But I tried swapping the host computer out and replace
it with a non-RAID computer. The "old" one was a < 1 year old,
Pentium4-based, top-of-the-line Dell XPS. The "new" one is a computer
I built: Gigabyte GA-K8NSNXP-939, AMD 64 3400, and a non-RAID SATA HD
(WD2500). 2GB RAM. The whole thing works now and is solid. Go
figure. My testing shows that the transfer to host time (from frame
grabber to host RAM) is a little faster (used to be 23ms now is 21ms)
and writing to disk seems just slightly faster as well. Whatever it
bought me, it was enough.

Sometimes you just can't figure this stuff out on paper and you have to
do the empirical tests.

Now I'm just bummed that my cool new computer (clear acrylic case, blue
LED fans, etc) is now dedicated to an imaging setup in our lab and I
have to use the less-exciting Dell for my day-to-day work.

 

[Peter]

Thx for posting back.