Date: Tue, 2 Sep 2014 17:17:28 +0200 From: Borja Marcos <borjam@sarenet.es> To: "Steven Hartland" <killing@multiplay.co.uk> Cc: FreeBSD-scsi <freebsd-scsi@freebsd.org> Subject: Re: Samsung 840 Pro SSD and quirks Message-ID: <59E9F0BF-1B42-40E9-BF1E-E7AFB60C3B27@sarenet.es> In-Reply-To: <14D38CFE3887426D9065E26F50457F30@multiplay.co.uk> References: <A04E6D4A-907E-45AB-9668-0BF6827FD178@sarenet.es> <D8A848BC8761493EA5A049BFA77852CF@multiplay.co.uk> <93D764A8-01AE-42FA-8020-65CEB6C7D64C@sarenet.es> <14D38CFE3887426D9065E26F50457F30@multiplay.co.uk>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sep 2, 2014, at 5:07 PM, Steven Hartland wrote: > Thanks for the confirmation Borja I was a little confused why > our two results differed. What do you use for your benchmarks? I am still playing with this, so I = can run the same tests just in case. I have done something pretty straightforward, just creating a pool, a = dataset, and running bonnie++ on it. I also have a backplane=20 >=20 > For a 12 disk system you'll likely need two SAS2 controllers, > or at least 12 SAS lines otherwise you will hit controller > throughput issues as a 840 can pretty much saturate a single > SAS2 lane on its own. >=20 > At that point you'll also start to see other issues. >=20 > I'd strongly suggest moving to stable/10, if you haven't already, > particularly if you have large amount of RAM in the system > otherwise you will become CPU bound on ARC hash lookups. Yes, I'm following -STABLE but this braindead machine has just *one* = PCIe slot, so I am limited to one controller. In my case, a SAS2008 (mps driver) with = a SAS expander.=20 mps0: <LSI SAS2008> port 0x3f00-0x3fff mem = 0x90ebc000-0x90ebffff,0x912c0000-0x912fffff irq 32 at device 0.0 on = pci17 mps0: Firmware: 18.00.00.00, Driver: 19.00.00.00-fbsd mps0: IOCCapabilities: = 1285c<ScsiTaskFull,DiagTrace,SnapBuf,EEDP,TransRetry,EventReplay,HostDisc>= Anyway, my main concern is not that maximum throughput, the system will = be much faster than the same using "classic" hard disks :) Borja.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?59E9F0BF-1B42-40E9-BF1E-E7AFB60C3B27>