On Dec 6, 2007 2:44 PM, Aaron Kulkis <[EMAIL PROTECTED]> wrote: > <snip> > > Also, the writes are all in parallel. The above makes it sound like > > the writes of updated stripes, and the write of the checksum are > > serial... they should all be posted nearly simultaneously (some > > serialization introduced by the CPU). > > No, they are NOT in parallel. The are issued sequentially. > They may overlap (only if you have SCSI, or if all of the > disks are on different controllers), but they are not in > parallel. > I never use slave disk drives. Pure masters. As you say, Master & Slave access is always sequential.
Alternatively I've setup older systems with 10 IDE channels to test (I used 5 pci cards). It fell apart speed wise on PCI. I have not tried it on PCIe. OTOH, you can setup a 4 IDE channel configuration that really pushes the drives hard. Basically goes as fast as the drives will run. And in the modern machines, we have MBs with lots of SATA ports. Those are typically one-to-one connections. And if you are using a PMP (multiplexer) people are reporting pretty good speeds. Far better than sequential. I'm not sure they are as good as SCSI. Greg -- Greg Freemyer Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer First 99 Days Litigation White Paper - http://www.norcrossgroup.com/forms/whitepapers/99%20Days%20whitepaper.pdf The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
