Hi Guys,

 

I currently have a 12 drive system using a AOC-SAT2-MV8 card in a regular PCI slot.

The other four drives are connected directly to the motherboard.

 

As my system has grown my write and parity check/rebuild speed have become pretty bad.

I'm getting about 15,404 KB/sec rebuilding a drive right now.

 

I am considering upgrading to a AOC-SASLP-MV8 card to help performance.

My motherboard (Asus P5QPL-AM) has a PCIex16 slot.

 

Can anyone give me an idea what kind of performance increase I can expect with this upgrade?

or offer any other comments about it.

 

Thanks in advance,

 

Kent

Regular PCI is 33mhz 32bit, so upgrading to PCIe will bring a lot of performance. Keep in mind that the PCIe version of this controller is 4x only and that your PCIe 16x slot is probably for a graphic card and may not work with oher controllers, you have to double ckeck. Other possibility to increase performance is to put your old controller in an appropriate for it PCI-X slot that is 133mhz 64bit in some other motherboard.

Thanks for the quick reply Starcat.

 

I thought about getting a motherboard with a PCI-X slot but all I can find are server boards which are much more expensive that the new controller.

 

I did a little goggling about the PCIe graphics only issue, but can't seem to find anything definitive.

It seems most of the issues are with second and third slots.

 

Can anyone running a similar configuration confirm if ASUS boards are prone to this problem ?

 

Thanks,

 

Kent

Check ebay for surplus server class mobos, all they have PCI-X. Server class mobo may have some other added benefits like build in IPMI (no monitor and keyboard needed anymore to configure BIOS) and more decent intel NICs, etc.

As was said, the PCI bus is limited to 133 MB/s for both up AND down for all devices. Your speed of 15 MB/s means you likely have 8 drives on the bus, perhaps less but you're doing reading and writing which can slow things down.

 

A 1x lane on the PCI Express bus provides 250 MB/s in each direction PER SLOT.

A 4x lane on the PCI Express bus provides 1000 MB/s in each direction PER SLOT.

 

The PCI Express SuperMicro card has some of its own limitations, so realistic speeds of using all 8 drives on the card result in speeds anywhere from 60 MB/s to 80 MB/sec.

 

If you can find a motherboard with 2 4x or 8x lane PCI Express slots then you can utilize both with 2 SuperMicro cards and not have any real bandwidth limitations for a 22+ drive system (typically 6 SATA on the MB and then your 16 drives via controller card).

Look here, the PCIe version of the card is much slower per port than the PCI-X version:

http://lime-technology.com/forum/index.php?topic=4990.msg74634#msg74634

It might be slightly slower than it's PCI-X counterpart, but PCI-X is obsoleted by PCI-Express and it's getting significantly harder and costlier to find PCI-X motherboards than PCI-Express motherboards.

 

Not so on surplus ebay and he already has the PCI-X controllers...