Re: HOWTO - Speed up IDE HD's - raid
Thus spake Roger Chrisman ([EMAIL PROTECTED]): > Mike Fedyk wrote: > > > These fancy tricks might not be worth it though if your system bus is > > > 33MHz. My two PIII servers have 33MHz system bus (PCI host bridge). So I > > > don't think it would be worth the trouble on my servers. > > > > > > Someone who knows more about RAID please tell me if I am mistaken about > > > that. > > > > Oh, I think it'll be useful. Remember, PCI at 32bits and 33Mhz can > > transfer 132MBytes/sec, and your drives won't fill that up. Also, once you > > start seeking, your disk throughput goes down radically. > > Mike, > > Thanks for this. I have a couple IDE drives sitting around so might try this. > I had thought the 33MHz mother board host bridge (aka system bus?) was going > to be the bottle neck on my old PIII board. > > Any book suggestions or other resource suggestions where I might read more > about PCI bus speeds, mother board host bridge speeds, and this kind of > hardware performance math? There seems to be considerable confusion about PCI bus speeds. The latest PCI spec (2.2 IIRC) allows for speeds of 33 or 66MHz, but most motherboards still run at 33 (and most adapters ditto). OTOH the *memory* bus may well be running at 800MHz or faster. But that won't help disk speeds. -- |Deryk Barker, Computer Science Dept. | Music does not have to be understood| |Camosun College, Victoria, BC, Canada| It has to be listened to. | |email: [EMAIL PROTECTED] | | |phone: +1 250 370 4452 | Hermann Scherchen. | -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: HOWTO - Speed up IDE HD's - raid
In article <[EMAIL PROTECTED]>, Alvin Oga wrote: > >> RAID 1 is one strategy for getting 'faster' read going. > > > http://www6.tomshardware.com/storage/2329/fastrak66-14.html > > > "its" linearly faster for reading ... but also linearly slower for writing >:-) First, I cannot see that statement (writing linearly slower) confirmed on the page you mention, and second, I wonder why that would be. When writing one block of data to a raid1 array of N disks, the block indeed needs to be written N times -- but it can be sent to each disk simultaniously, so it should take constant time. Sure, writing to a raid 1 array will never be as fast as straight to disk, but it shouldn't be all that much slower. Thanks, joostje -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: HOWTO - Speed up IDE HD's - raid
Mike Fedyk wrote: > > These fancy tricks might not be worth it though if your system bus is > > 33MHz. My two PIII servers have 33MHz system bus (PCI host bridge). So I > > don't think it would be worth the trouble on my servers. > > > > Someone who knows more about RAID please tell me if I am mistaken about > > that. > > Oh, I think it'll be useful. Remember, PCI at 32bits and 33Mhz can > transfer 132MBytes/sec, and your drives won't fill that up. Also, once you > start seeking, your disk throughput goes down radically. Mike, Thanks for this. I have a couple IDE drives sitting around so might try this. I had thought the 33MHz mother board host bridge (aka system bus?) was going to be the bottle neck on my old PIII board. Any book suggestions or other resource suggestions where I might read more about PCI bus speeds, mother board host bridge speeds, and this kind of hardware performance math? Thanks, Roger TEFLChina.org -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: HOWTO - Speed up IDE HD's - raid
On Sat, 7 Feb 2004, Roger Chrisman wrote: > > fun stuff > > RAID 1 is one strategy for getting 'faster' read going. http://www6.tomshardware.com/storage/2329/fastrak66-14.html "its" linearly faster for reading ... but also linearly slower for writing :-) "it" is the proper raid config ... if you only write once and read it back a gazillion times like google, than it'd make sense to use stripping > RAID 1 is a flavor where you take two disks of the same size and have the > computer treat them as one disk. stripping by itself does NOT allow you to read data 2x as faster sripping ( raid0 ) makes two 80GB look like one bigger 160GB disks ( if the data is only written once, you probably can't read all data ( 2x faster across 2 different disks .. mirroring ( raid1 ) plus stripping across 2 raid1 does allow you read 2x faster ... but you lose 1/2 of your disks to duplicate data ( "mirrors" ) what you'd want is raid01 or raid10 ( slightly different ) more fun stuff ( raid differences ) http://1u-raid5.net/Differences/ c ya alvin -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
