lee@infonode.ingr.com (Lee McCain) (02/11/91)
I have a Seagate ST1144A disk drive drive by an IDE 16-bit 1:1 interleave
controller. This drive is in a 386-33mhz w/64k cache machine. The bus is
running at 10mhz.
The drive specifications state that the data transfer rate is something like
1.6mg/sec. However, running the hard drive benchmarks from within Check-It,
a 594.6K/sec transfer rate is shown.
Does anyone out there known of a reason why I can't seen to get the 1.6mb/sec
or so transfer rates?
Thanks in advance.
Lee McCain
...!uunet!ingr!se_bbs!lee
--or--
lee@ingr.comjohn@jwt.UUCP (John Temples) (02/26/91)
In article <4663@cocoa46.UUCP> reichert@motcid.UUCP (Chuck KD9JQ) writes: >The current 1 to 1 interleave gives 920 - 970kbs transfer rate. Using what -- CoreTest? I just ran CoreTest on a Conner CP3204, and got a very impressive 1100 kb/sec transfer rate with no software disk caching enabled. I suspect that this figure is almost totally meaningless. Since the Conner's on board cache is at least as large as the maximum block size can CoreTest use, I think all I'm seeing is the speed at which I can read from the drive's cache. I doubt that CoreTest is able to force a physical read from the drive. After using the drive for the while, it certainly didn't feel like I was getting the impressive performance I expected. I ran a simple C program I use to benchmark disk performance which writes 1024 records of 1024 bytes each, then reads them back in sequence. The write rate was an appalling 70 kb/sec, with the read rate not much better at 140 kb/sec. Results were similar under both DOS and UNIX. Suspecting the non-cached 20 MHz 386 wasn't fast enough to keep up with 1:1 interleave at 12 Mbits/sec, I tried the drive on a cached 386/33, with the same results. Now that I find the Conner to be significantly slower than a 1:1 ST-506/MFM drive in "application level" transfer rates, I wonder if I've set something up incorrectly, or is a 386/33 just not fast enough to run 1:1 at 12 Mbits? Should the drive be reformatted to 2:1, or should I get a 486/33? Will I get better performance from ESDI at 10-20 Mbits/sec? -- John W. Temples -- john@jwt.UUCP (uunet!jwt!john)