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Subject: Re: Reassign Certain Files to RamDisk
Author: Mark Flanagan
Date: 2000-11-29 16:19:00

Only if you have PCI 2.1, I think. Otherwise the PCI bus itself is limited to...one hundred something mb/s (can't remember the # off the top of my head...). At least, that is how I have read the docs (haven't been able to find a good definition of PCI 2.1 yet, or how to determine if it's supported by any particular chipset/motherboard. Anyone?)

-Mark Flanagan
Senior Analyst
Dynamic Engineering, Inc.
757 873 1344 x-387

-----Original Message-----
Sent: Wednesday, November 29, 2000 6:49 AM
To: xansys

I have 2 PC's of similar speed but with better I/O systems. Both have 10krpm
SCSI disks with a Raid controller. This gives me about 120 mb/sec I/O
performance which is a lot faster than the IDE's you probably have. The only
drawback is that the 10krpm disks are not super reliable. One did go out
last year. Recovering files is hard since files are spread across the disks
in a Raid system so you have to assume a disk could fail at any time and
have your files backed up. There are now faster SCSI disks (160 mb/sec)
which should increase to 240mb/sec in a Raid system.

Mark Rodamaker
MCR Associates
Sunnyvale,California
voice: 408-736-1636

----- Original Message -----
To:
Sent: Wednesday, November 29, 2000 7:26 PM

> In my on-going quest to quiet down nonlinear ANSYS runs on a somewhat
modest
> PC (500 MHz & 256 Meg RAM), I have tried the /ASSIGN command to move some
> ANSYS solver files to a RamDisk under Windows NT. I am trying:

> /assign,EMAT,FAST,EMAT,z:
> /assign,ESAV,FAST,ESAV,z:
> /assign,OSAV,FAST,OSAV,z:
> /assign,FULL,FAST,FULL,z:
> /assign,EROT,FAST,EROT,z:

> where the Z drive is the RamDisk. It takes some preliminary work to
estimate
> the required size of the RamDisk Z drive. These element matrix files are
of
> relatively modest size, in comparison with the RST file, TRI file (when
> using frontal), DB files, and some other files, which remain on the hard
> drive.

> So far, it does seem to quiet down the hard drive, and speed up ANSYS. I
> suspect that there may be a considerable speed gain using these
techniques,
> though I don't know how the benefit would compare to using on large RAM
> computers, or those with double SCSI hard drives, and files assigned
between
> the two drives.

> Has anyone else tried this trick, and have a comment to make on its
> effectiveness?

> Peter

> Peter C. Budgell
> Senior Development Engineer
> Innovative Steam Technologies Ltd.
> 549 Conestoga Blvd.
> Cambridge, Ontario, Canada N1R 7P4
> mailto:pbudgell
> Tel: 519-740-0757 ext.249
> FAX: 519-740-2051
> http://www.otsg.com

Posts possibly associated with message #18457AuthorDateScore
18448Reassign Certain Files to RamDiskPeter Budgell2000/11/29 
18449Re: Reassign Certain Files to RamDiskMark Rodamaker2000/11/29 
18457Re: Reassign Certain Files to RamDiskMark Flanagan2000/11/29