ON: Mon, 17 Nov 2003 14:30:32 -0600
Jeff Walther <[EMAIL PROTECTED]>
Has anyone gotten good Sustained Data Rates (as measured by something like Express Pro-Tools from Atto) in their Write performance with any of the ATA cards? Meaning up above 20 MB/s.
I have a S900 233Mhz with an OWC ACARD CN 2490 v2.14(PCI ATA 133 card) driving a 120Gig IBM (IC35L120AVV207-0) ATA drive from OWC with three partitions.
That's a 180GXP drive.
Also two 9.1Gig IBM (DPSS-309170M) SCSI drives on the internal bus.
That's the 36LP.
Speed reported by ATTO Express Tools v2.7 is:
80 Gig Storage volume ATA on bus 2 ACARD: Peak Read= 29.86 MB/s; Sustained Read= 29.09 MB/s Peak Write=25.75 MB/s; Sustained Write= 24.64 MB/s
30 Gig Boot Volume ATA: Peak Read= 29.98 MB/s; Sustained Read= 28.83 MB/s Peak Write=25.42 MB/s; Sustained Write= 24.48 MB/s
Ah, thanks, Ernie, that's really good to know. So, it appears that the sub-20 MB/s sustained writes are an artifact of the VST card. Still, as I mentioned before, hard to complain on a card that's not even supposed to work on our machines...
9.1 Gig SCSI on Bus 0:
Peak Read= 8.28 MB/s; Sustained Read= 7.75 MB/s Peak Write=8.75 MB/s; Sustained Write= 8.56 MB/s
IBM's datasheet lists sustained rates for that drive of 19 - 30 MB/s but, of course, you can't get up to that with it on the internal bus which is limited to 10 MB/s. The numbers you do get are interesting. 10 MB/s is the theoretical maximum on that bus, which, of course, means that the reality is going to be less. I wonder if your numbers are the realistic maximum for that bus, no matter how much faster the drive is. The drives you're using should not be the limiting factor, although, I bet you're using an adapter (80 to 50 or 68 to 50) on those drives, so that could slow them down, I suppose. Hmmmmmmm.....
Ah, but here's a chance to compare IBM's numbers to reality. Going back to the 180GXP, you seem to get about 25 - 30 MB/s out of it. And IBM says.....................
56 - 29 MB/s which is a darned odd way to list it. Based on that one data point, it looks like we should keep our expectations to the low end of IBM's reported Sustained Data Rates.
I apologize for not having the common accepted drive names. I can't find my
Invoices and got the info from Apple Profiler. I don't want to tear down the system
right now. If you want I can unhook the drives tomorrow and read the labels.
No problem. I looked up the model families from the table I mentioned in my earlier post a couple of days ago. Actually, I went ahead and saved that table on my hard drive as an html file, because it's just so darn useful to have around, especially when shopping on Ebay for drives.
Thanks for the great information, Ernie.
Jeff Walther
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