Date: Mon, 16 Dec 2002 12:07:47 -0800 From: "Jin Guojun [DSD]" <j_guojun@lbl.gov> To: Hari Bhaskaran <subscr@spider.netmails.net> Cc: freebsd-hardware@FreeBSD.ORG Subject: Re: Optimal conf for two HDDs + 1 CD on 2 UDMA/100 channels Message-ID: <3DFE3293.94B1808F@lbl.gov> References: <20021215184343.A64802@spider.netmails.net> <3DFD285E.96FE73AD@lbl.gov> <20021215193019.A64865@spider.netmails.net>
next in thread | previous in thread | raw e-mail | index | archive | help
Hari Bhaskaran wrote: > Jin, > > Now after reading your question, I do realise something is > rong. My motherboard is a Super Micro P4SBE. > http://www.supermicro.com/PRODUCT/MotherBoards/845/P4SBE.htm > It says it has "Dual Ultra DMA 100 IDE Bus Master". However, only one > of the slots is blue in color. Then the manual says elsewhere > that "The 80-wire ATA66/100 IDE hard disk drive cable that came > with your system has two connectors to support two drives". The blue color indicates primary bus. The secondary bus is still 100MBps as SuperMicro says, although their manual usually has mistakes :-) So, you can use both to connect your disk drives. > This would probably mean that I can only use one capable for the > harddisks anyways. Both harddisks are ATA-100. In case if the secondary IDE bus is not 100, at least it will be ATA-66. Drives you mentioned below have about 60 MBps peak bulk transfer rate, so it will work OK on ATA-66 IDE bus. See below for details. Anyway, you can connect a ATA-100 drive to any IDE bus, it will work at the maximum bus rate if bus is slower than the drive. > The cable itself (that came with the MB) isn't long enough to > connect both the drives, so I went to Frys and got a longer > (36") cable. Apparently that doesn't have a 'blue' end, > although the store confirmed it is UDMA/100 capable. Is this > normal? > I would not say normal or not normal. It is possible. You can confirm it yourself. The 80-wire cable has thin wire than 40-wire cable. It is easy to see. > > BTW, HDDs are > http://www.westerndigital.com/products/products.asp?DriveID=12 > and > http://www.maxtor.com/en/documentation/quick_specs/diamondmax_plus_9_quick_specs.pdf > (120GB one) > WDC drive has 60MBps bulk Tx rate (a possible 75MBps cache Tx rate). Maxtor does not say anything about media Tx rate on this model. Based on experience, single drive may have higher bulk Tx rate, but parallel (stripping) may be not. Since your motherboard has 845 chipset, any single of these drive will saturate the IDE bus. So it may not be worth to use two drives to increase performance. Use of two drives is only good to double the capacity. So, how to connect these drives is trivial. Either vinum or ccd will do the job. > > On Sun, Dec 15, 2002 at 05:11:58PM -0800, Jin Guojun [NCS] wrote: > > There are a couple of separated issues in answering your question: > > > > (1) Not all IDE controllers are really works in stripping well. > > (2) Does an inactive IDE device will affect an active IDE device? > > > > You seem concerning the second issue in your email. It is usually not > > the problem. > > However, the first issue may be a problem, and it depends on what type of > > IDE controller you have. > > > > For example: > > AMD MPX IDE controller has two real IDE buses, which give you over > > 190 MBps aggregated throughput. So, stripping will help. > > Intel PCI chip sets seem not have two really separated IDE buses. So, it > > does not matter how you connect your drives, you will not get aggregated > > throughput near 100 MBps. So, do whatever it is convenient for you, > > it will not make different. > > VIA/ALi/NVIDIA/SiS chip sets all have different features. > > > > So, you need to test your IDE controllers to decide how you connect > > your drives. Normally, what you proposed is a better way. > > > > -Jin > > > > Hari Bhaskaran wrote: > > > > > > Hi, > > > > > > I plan to use vinumfs on FreeBSD 4.7 using two IDE harddisks 120G each. > > > Motherboard has two UDMA/100 IDE slots. > > > > > > If I didn't have the CD, I would expect it will be better to put both > > > HDDs on different cables since they wouldn't compete for the channel > > > that way. But then the CD would have to be at least a slave on one of > > > the cables. Would it degrade the performance of the HDD on the same > > > cable?. The CD drive is Mitsumi SR242S1 -- an I am not sure if it is > > > slow or fast. I would use the CD only rarely (probably only during > > > initial install). The HDD doc says it is OK to put a CD on the > > > same cable so long as the HDD is the master. Would that take care of > > > any performance issues? > > > > > > Is any one configuration better suited for FreeBSD or vinumfs for that > > > matter. Any help is greatly appreciated > > > > > > -- > > > Hari Bhaskaran > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > > with "unsubscribe freebsd-hardware" in the body of the message > > To Unsubscribe: send mail to majordomo@FreeBSD.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3DFE3293.94B1808F>