Comments on: LSI SAS 9207-8i PCIe 3.0 HBA Overview – Eight Crucial M4 SSDs Pushed to 4.1GB/s Performance

By: Alex Narayan

Alex Narayan — Sun, 04 May 2014 17:24:00 +0000

Seems like most people want details of how the drives were configured so they can either try to do the tests themselves or just gain from the added transparency.

By: ErikL

ErikL — Thu, 21 Mar 2013 15:32:00 +0000

Could you provide the settings you uses for the raid strip? i.e Strip Size,, Read Policy,Write Policy, IO etc. I just purchased this card and have been playing with configures to get an optimum result.
thanks!

By: James

James — Thu, 10 Jan 2013 00:39:00 +0000

There’s a clarification that needs to be made in this article.

The theoretical raw bit rate of PCIe 2.0 is around 4GB/s. PCIe is a packet-based store-and-forward protocol, so there’s packet overhead that limits the theoretical data transfer rate.

At stock settings, this overhead is 20%. However, one can increase the size of PCIe packets to decrease this overhead significantly (to around ~3-5%) in BIOS.

I know this because I’ve raided eight 128GB Samsung 840 Pro with the LSI MegaRAID 9271-8iCC on a PCIe 2.0 motherboard, and I’ve hit this limit on sequential reads. In order to get around it, I raised the PCIe packet size, but doing so increases latency and may cause stuttering issues with some GPUs if raised too high.

By: Ferky

Ferky — Sat, 24 Nov 2012 21:42:00 +0000

Great review ! Very nice to see suvh great info on this subject.
BTW does this HBA support Trim ?

By: GregChernis

GregChernis — Thu, 22 Nov 2012 18:35:00 +0000

In reply to Christopher Ryan. I had a chance to try SoftRAID0 on IT firmware, RAID0 with IR firmware, and 9286-8i RAID0, all with Intel 520 480GB SSD. All configurations are speed-limited at 5 drives since I am rinning PCIe 2.0 x8. Time for a new motherboard, I guess...