Date: Mon, 10 Nov 1997 10:22:27 -0800 (PST) From: Tom <tom@sdf.com> To: Mark Mayo <mark@vmunix.com> Cc: freebsd-hardware@freebsd.org Subject: Re: Diamond FirePort 40 Message-ID: <Pine.BSF.3.95q.971110101441.4591C-100000@misery.sdf.com> In-Reply-To: <19971110023955.15338@vmunix.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 10 Nov 1997, Mark Mayo wrote: > Has anyone tried the Diamond FirePort 40 or FirePort 40 Dual > SCSI controllers yet? How are they? They work, but I'm not sure if the driver turns Ultra on yet. > It appears to just be a NCR 53c875 controller, but their benchmarks > are putting it ahead of the Adaptec 2940/3940UW. I'm not sure > how good the 875 is versus the 810, but I know from my own testing > that the 2940U kicks the NCR 810 around the block... The 810 is a Fast controller, and the 2940U and Ultra controller. > On my home system, I was getting about 4MB/s read and write out of > a Quantum Fireball UltraSCSI drive with the 53c810. When I > plugged the same drive into an old 2940U my throughput jumped > to 5.5 MB/s on writes, and 6.1MB/s on read.. I used iozone > with a gigantic file (with 512 and 8192 bytes blocks - same > effect). 512 and 8192 blocks are quite small. This gives a lot of command overhead, that any Ultra controller will handle better. I bet if you try 64k blocks, you will notice little difference. The Adaptec controllers process commands a bit more quickly. > I'm in the marketplace for a new SCSI controller for a server > system I'm building, and I'd love to go with the 875 based > Diamond FirePort - the price is right. I guess I'm wondering > why the 810 performs so crappily under FreeBSD, and if I can > expect the same crappy performance from the 875 under FreeBSD? > > Is the ahc driver really that much better?? It has nothing to do with the driver. It is the card. First of all you are comparing an Ultra to a Fast controller. Adaptec 2940/3940 controllers can keep outstanding commands on the card, speeding up simultaneous commands. The only time you ever notice this, if you are issuing a lot of commands. Also, the ahc driver has some reliability problems on some hardware. If your drives do funny things, the ahc driver may not be able to sort it out. See "timed out while idle" problems in archive. > TIA, > -Mark Tom
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.3.95q.971110101441.4591C-100000>