4x X25-V Striped 10MB Read Speed

[Strmtrper6]

http://i.imgur.com/gXFHv.jpg

That is just a simple windows array set up in diskpart. It isn't aligned. I tried to create an array using the raid card but every time I benchmarked it, it would kick out/orphan one of the drives and destroy my stripe set.

Alright, here is my situation.

I have four Intel X25-V's hooked up to a PCI-X raid card (Koutech PSA421 w/ Silicon Image sil3124raid chip). I know it isn't but best card but I was on a budget and would like to squeeze whatever performance I can out of this setup.

I am running Windows Server 2003, and shutting it down or rebooting is usually not an option.

I am looking for the best way to align the drives if they were made into a striped set.

Also, am I correct in thinking that I am better off doing a Windows software raid instead of a hardware raid, as the onboard chip really doesn't handle any processing and it would be easier to recover a Windows raid in the event of a controller failure?

Thanks,
Aaron

 

[Zap]

What are you trying to accomplish with this stripe set? More I/Os? More throughput? Higher capacity?

You might be better off (unless you needed the throughput) selling your four drives and controller, and just buying a single Intel 160GB drive. In the Hot Deals forum here there is a thread about a $180 Intel 80GB drive, and somewhere in the thread someone mentions getting the 160GB drive for $385.

 

[Strmtrper6]

I/Os and throughput. It is for serving a database. My company won't let me sell them and buy something else. I pretty much have to make this work.

I would still need a controller regardless. The server only has SCSI and they are all populated. Also, one 160 is barely faster than two 40s.

Space is not a problem. I am actually only using half of each drive to make sure there is plenty of spare area for wear leveling/GC.

Single drive performance on all four drives seems normal:
http://i.imgur.com/KeIfT.png

Once I raid even two together though, it goes down to <20 on all read speeds...

The write is scaling almost perfectly. within 10&#37; of adding the speeds of all four drives.

 

[sub.mesa]

Could you try RAID0ing them using Windows software RAID (i.e. in Disk Management)?

Not sure if it asks you for the stripesize; enter 128KiB when asked.

My benchmarks with 5 x Intel X25-V 40GB yielded ~1234MB/s of random read performance under multiqueue conditions. So they should be able to scale nicely with a proper RAID engine.

 

[Strmtrper6]

Thanks sub.mesa. I was using windows raid with the poor performance I was posting earlier. If I try to stripe it from the controller, it fails. It doesn't let you pick a stripe size, which seems odd to me.


*update*
I tried to format with 64k allocation units just because there wasn't much else to try. On a quick Crystalmark benchmark with only 100 megabyte size set I was hitting almost the speed of one drive in sequential reads, and my 512 reads were almost double that, but then when I tried to run a full benchmark of 1 gigabyte, one of the drives dropped and the controller/OS can no longer see it. The controller is reporting it failed. No idea when I will be able to reboot to see if it even comes back online.

I don't think I've ever had this much trouble building a simple raid array.

 

[sub.mesa]

You are still using the Silicon Image RAID drivers, probably.

My advice: don't use any of that fakeRAID stuff; deinstall the silicon image RAID driver; use the controller as normal AHCI controller; you may have to flash firmware of your controller to let itself register as normal AHCI controller.

Or just buy a good controller: SuperMicro USAS-L8i for example, 2x Mini-SAS means 8x SATA/300 devices connected to PCI-express x8 (2GB/s) bus. Link here:
http://www.supermicro.com/products/accessories/addon/AOC-USAS-L8i.cfm

Note that your chipset-powered SATA ports are the highest quality; slightly better than PCIe addon controllers.

So your problem is probably with the Silicon Image RAID drivers currently; i would avoid them like the plague.

 

[killster1]

You are still using the Silicon Image RAID drivers, probably.

My advice: don't use any of that fakeRAID stuff; deinstall the silicon image RAID driver; use the controller as normal AHCI controller; you may have to flash firmware of your controller to let itself register as normal AHCI controller.

Or just buy a good controller: SuperMicro USAS-L8i for example, 2x Mini-SAS means 8x SATA/300 devices connected to PCI-express x8 (2GB/s) bus. Link here:
http://www.supermicro.com/products/accessories/addon/AOC-USAS-L8i.cfm

Note that your chipset-powered SATA ports are the highest quality; slightly better than PCIe addon controllers.

So your problem is probably with the Silicon Image RAID drivers currently; i would avoid them like the plague.

isnt that card you recommend not pcie? It will work if you take the bracket off? checked and its only a 128$ card so its reasonable price.

 

[Strmtrper6]

As I said before, the server only has SCSI and they are all populated.

I didn't mention this but it doesn't have PCI-E either. Either of those options would have made this a lot easier. That is why I had to go with a PCI-X card.

Thanks for the advice though. I will try to uninstall the drivers and let use the default windows drivers.

The card ran great in my personal desktop, but it was PCI and obviously capped. Still, I can't even achieve those speeds on the PCI-X bus (nothing else is on this channel).

 

[sub.mesa]

A computer without PCI-express is an 'old' computer in my eyes. PCI-X is nothing more than PCI with more bit width and higher frequency; it still has all the downsides of the shared PCI bus; while PCI-express is like 100&#37; opposite of everything that PCI is.

You biggest problem at this point is that you're using low quality "FakeRAID" drivers by Silicon Image. As a related note i will say that using 4 high-end SSDs in an ancient system without even PCI-express may not be the best usage of these SSDs. For one, to actually use all the IOps you need a fast CPU too. Dropping the SSDs on the PCI bus may be quite a waste of potential performance.

I recommend a cheap 40 dollar motherboard with 6x SATA, a 30 dollar dualcore CPU and you've already got a superior setup. If money is an issue you can stay on the AMD side.

If you don't want to buy anything new, i would focus on flashing your PCI-X FakeRAID controller to a PCI-X SATA/AHCI controller without RAID; then deinstalling any silicon image RAID drivers on your system and using Windows software RAID instead. That would work, and with reasonable performance. Thought he PCI-X bus would still limit the SSD performance; it is still a shared access half-duplex bus-technology; not a modern point-to-point interface like PCI-express.

 

[Emulex]

use software raid-5 man or raid-10 doesn't win7 have that ? or server 2008?

pci-X is quite fast. 64bit (versus 32) and iirc twice as fast but make sure you don't forget the whole 3.3V and 5V situation. that is a pain. i'd go find an old smart-array 642 on the cheap and give it a shot. maybe with some BBWC you could get a little bonus write speed