Author: Matt Taylor
Date: 10:48:13 02/21/03
Go up one level in this thread
On February 21, 2003 at 09:51:34, Robert Hyatt wrote: >On February 21, 2003 at 05:31:35, Matt Taylor wrote: > >>On February 20, 2003 at 18:23:22, Robert Hyatt wrote: >> >><snip> >>>My cpus don't run blazing hot, although there is another significant performance >>>difference >>>in our boxes. I can copy 8 gigs of data in 30 seconds. That is important for >>>chess endgames >>>with tables. I don't think you can get 1/10th of that speed with IDE drives of >>>any kind. >>>But that is yet a different subject. >><snip> >> >>(2) Western Digital 80GB 8MB cache 7200 rpm >>3ware 7000-2 RAID controller >> >>Buffered Read: 94 MB/sec >>Sequential Read: 49 MB/sec >>Random Read: 6 MB/sec >> >>Buffered Write: 87 MB/sec >>Sequential Write: 58 MB/sec >>Random Write: 12 MB/sec >> >>This would be 1.4 GB in 30 seconds. Nowhere near 8 GB, but it's more than 10%. >>Also, this was done on an NT box using NTFS, and NTFS is notoriously slow. >>Seeking all over a 7200 rpm drive really cripples the "sequential" speed. >> >>That is the low-end model RAID controller in 2-disk RAID-0. 8-disk RAID-0 is >>pretty fast. They claim speeds up near 600 or 700 MB/sec in which case it would >>be copying 18 GB in 30 seconds. The 7500-8 costs something like $350 or $250, I >>believe. That array would be about $1,000. The 8500-8 is what I would use if >>money were no object. >> >>-Matt > >I've got an 8-drive IDE raid array here we are playing with for backups, and >it is _not_ fast. This is an 8 x 250gig device and no, I don't remember who >made it as it isn't ours (ours = CIS) it was an evaluation device from our >IT folks up the street. However, the random speed is more important than the >sequential read for tablebases, and the 15K SCSI drives have 1/2 the latency >of the best IDE drives so far that I have seen (7200 RPM). I'll run the 8 gig >copy on this array monday to get a number, but when I tried it last time it >took over 5 minutes total. Which is where I got my 10x number. > >Beware of claimed speeds also, as that is typically drive buffer to memory, >which is not the same as copying large files where buffer means zero. Throughput listed for Barracuda V drives is listed as 72 MB/sec. Here is benchmark data for the Escalade in particular: http://www.3ware.com/products/benchmarks.asp For some reason, I was remembering it as 600-700 MB/sec. It is much lower, but it still comes to around 6 GB over 30 sec sequential read speed, and that's on a 5400 rpm drive. The Barracuda V drives would abosolutely fly. 10K rpm ATA drives are coming. Western Digital will soon release a line of 10K rpm Serial ATA drives, basically a SCSI drive on a Serial ATA interface. I think rpms is really the -major- seperating factor between SCSI and ATA right now. A good ATA RAID controller will do everything the SCSI disk already does. -Matt
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