SMARTDRIVE

MSDOS 6.2 Smartdrv.exe Sends Unibase by DMAC DOS Workstation Performance To The Top of Heap

Question: What takes the performance of a 486-66 PC from the worst of the heap at 40 minutes to the top of the heap at 6 minutes? Answer: Install MSDOS 6.2 or newer on the PC and enable the smartdrv.exe which comes with DOS with no command line parameters in the autoexec.bat.

For years we at DMAC have used a series of tests call MTEST to verify that drun is performing correctly. When we started back on 8088's I think the time to finish correctly was 14 hours. Listed
below are the MTEST times now on the 486-66 PC:

   Version                                        Time(mins)

   Standalone DOS                 40

   Novell Network OS/2            35

   Novell Network DOS             33

   Standalone OS/2                 8

   Standalone DOS/Smartdrv       6

(In comparison MTEST takes 2 minutes on our single processor Tandem UNIX box.)

Write-behind Cache Gives Speed

We know that the write-behind caching is what is speeding up the process. Users now using smartdrv can declare an output device to be on a fast local drive and when finished the user can copy the output file to the network. This will save time.

Use of Device Type "type" Helps

In Unibase by DMAC release 7.32i, now entering quality assurance, the new drive type "type" allows using a local drive for output and automatically copying over the file to the network. See the separate article.

Pitfalls Are A Plenty

Are there pitfalls? Yes. 1) The smart drive which comes with Windows (not with DOS) is different. It gave a time of 1 hour 40 minutes. 2) At the end of the run there may be data in the output file which has not been written to disk. The user can use the command "smartdrv /C to write this information. 3) If you use the command "smartdrv /X" write-behind caching is disabled. 4) A slow local disk may negate any speed advantages.

The user should experiment carefully to verify the results. If the eight fold savings hold true, then copying needed non changing files to a Standalone PC version of Unibase, doing druns, and returning results to the Network now makes sense in large jobs on the Novell network. The environment variable for building indexes discussed elsewhere in this issue moves the index file being built from the local drive back to the Novell Network at completion.

Faster CPU; The Bigger Ratios

A faster machine, such as a Pentium, will produce even better speed improvement. This is reflected in MTEST times in a Novell Network being within a minute of each other (32 vrs 33) whether a 486-33 or a 486-66 is used.

Is This Flaw In Network Approach?

Is the slow Novell time caused by the 10 mbps ethernet? No. One user tested the new 100 mbps ethernet and found a speed improvement of about 30 percent. We think the problem is in the way the software/hardware of the ethernet board work at the PC.

Try Smartdrv Everywhere in Dos

We think these ideas can be used with other programs and environments -- perhaps even with our competitor's products. Good hunting.