Date: Fri, 30 Oct 1998 19:43:47 +0200 (EET) From: Narvi <narvi@haldjas.folklore.ee> To: Tom <tom@uniserve.com> Cc: "Milliken, Scott" <MillikS@salestech.com>, "'stable@freebsd.org'" <stable@FreeBSD.ORG> Subject: RE: RAID support in FBSD? Message-ID: <Pine.BSF.3.96.981030193947.13946H-100000@haldjas.folklore.ee> In-Reply-To: <Pine.BSF.4.02A.9810300844340.6748-100000@shell.uniserve.ca>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, 30 Oct 1998, Tom wrote: > > On Fri, 30 Oct 1998, Milliken, Scott wrote: > > > > Besides, a host based RAID controler takes RAID processor "offline" > > > too. > > > A DPT PM334 has a dedicated CPU and RAM, it just happens to be on a > > > PCI > > > card. > > > > > You're also limited by the speed of the PCI bus. If you're > > running a brand-spanking new motherboard with 100 MHz PCI then you > > *might* be able to come close to the performance of a lower end offline > > RAID (or SCSI-SCSI). Another advantage of offline RAID that wasn't > > And how are SCSI-SCS boxes not "limited" by PCI? > > It seems that SCSI-SCSI units are more limited, because they are > connected via a 40MB/s (or 80MB/s with ultra2) bus, but host based cards > are right on the PCI bus (132MB/s). This is wrong. Max sustained bandwidth for 33Mhz 32bit PCI bus is 80MB/s. 132MB/s is the theoretical peak bandwidth on an infinite burst transfer. For higher bandwidth, you need either wider (64 bit) or faster (66Mhz) PCI bus. Sander There is no love, no good, no happiness and no future - all these are just illusions. > > Tom > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.3.96.981030193947.13946H-100000>