338 lines
10 KiB
Plaintext
338 lines
10 KiB
Plaintext
.\" Copyright (c) 1983 The Regents of the University of California.
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the University of
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.\" California, Berkeley and its contributors.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)results.ms 6.2 (Berkeley) 4/16/91
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.\"
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.ds RH Results
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.NH
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Results
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.PP
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The following tables indicate the results of our
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test runs.
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Note that each table contains results for tests run
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on two varieties of 4.2BSD file systems.
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The first set of results is always for a file system
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with a basic blocking factor of eight Kilobytes and a
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fragment size of 1 Kilobyte. The second sets of measurements
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are for file systems with a four Kilobyte block size and a
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one Kilobyte fragment size.
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The values in parenthesis indicate the percentage of CPU
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time used by the test program.
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In the case of the two disk arm tests,
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the value in parenthesis indicates the sum of the percentage
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of the test programs that were run.
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Entries of ``n. m.'' indicate this value was not measured.
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.DS
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.TS
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box,center;
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c s s s s
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c s s s s
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c s s s s
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l | l s | l s
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l | l s | l s
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l | l l | l l
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l | c c | c c.
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4.2BSD File Systems Tests - \fBVAX 11/750\fR
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=
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Logically Sequential Transfers
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from an \fB8K/1K\fR 4.2BSD File System (Kbytes/sec.)
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_
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Test Emulex SC750/Eagle UDA50/RA81
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1 Drive 2 Drives 1 Drive 2 Drives
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_
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read_8192 490 (69%) 620 (96%) 310 (44%) 520 (65%)
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write_4096 380 (99%) 370 (99%) 370 (97%) 360 (98%)
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write_8192 470 (99%) 470 (99%) 320 (71%) 410 (83%)
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rewrite_8192 650 (99%) 620 (99%) 310 (50%) 450 (70%)
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=
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.T&
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c s s s s
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c s s s s
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l | l s | l s
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l | l s | l s
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l | l l | l l
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l | c c | c c.
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Logically Sequential Transfers
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from \fB4K/1K\fR 4.2BSD File System (Kbytes/sec.)
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_
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Test Emulex SC750/Eagle UDA50/RA81
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1 Drive 2 Drives 1 Drive 2 Drives
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_
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read_8192 300 (60%) 400 (84%) 210 (42%) 340 (77%)
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write_4096 320 (98%) 320 (98%) 220 (67%) 290 (99%)
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write_8192 340 (98%) 340 (99%) 220 (65%) 310 (98%)
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rewrite_8192 450 (99%) 450 (98%) 230 (47%) 340 (78%)
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.TE
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.DE
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.PP
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Note that the rate of write operations on the VAX 11/750 are ultimately
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CPU limited in some cases.
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The write rates saturate the CPU at a lower bandwidth than the reads
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because they must do disk allocation in addition to moving the data
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from the user program to the disk.
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The UDA50/RA81 saturates the CPU at a lower transfer rate for a given
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operation than the SC750/Eagle because
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it causes more memory contention with the CPU.
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We do not know if this contention is caused by
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the UNIBUS controller or the UDA50.
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.PP
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The following table reports the results of test runs on a VAX 11/780
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with 4 Megabytes of main memory.
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.DS
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.TS
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box,center;
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c s s s s s s
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c s s s s s s
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c s s s s s s
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l | l s | l s | l s
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l | l s | l s | l s
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l | l l | l l | l l
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l | c c | c c | c c.
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4.2BSD File Systems Tests - \fBVAX 11/780\fR
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=
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Logically Sequential Transfers
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from an \fB8K/1K\fR 4.2BSD File System (Kbytes/sec.)
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_
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Test Emulex SC780/Eagle UDA50/RA81 Sys. Ind. 9900/Eagle
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1 Drive 2 Drives 1 Drive 2 Drives 1 Drive 2 Drives
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_
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read_8192 560 (70%) 480 (58%) 360 (45%) 540 (72%) 340 (41%) 520 (66%)
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write_4096 440 (98%) 440 (98%) 380 (99%) 480 (96%) 490 (96%) 440 (84%)
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write_8192 490 (98%) 490 (98%) 220 (58%)* 480 (92%) 490 (80%) 430 (72%)
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rewrite_8192 760 (100%) 560 (72%) 220 (50%)* 180 (52%)* 490 (60%) 520 (62%)
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=
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.T&
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c s s s s s s
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c s s s s s s
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l | l s | l s | l s
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l | l s | l s | l s
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l | l l | l l | l l
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l | c c | c c | c c.
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Logically Sequential Transfers
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from an \fB4K/1K\fR 4.2BSD File System (Kbytes/sec.)
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_
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Test Emulex SC780/Eagle UDA50/RA81 Sys. Ind. 9900/Eagle
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1 Drive 2 Drives 1 Drive 2 Drives 1 Drive 2 Drives
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_
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read_8192 490 (77%) 370 (66%) n.m. n.m. 200 (31%) 370 (56%)
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write_4096 380 (98%) 370 (98%) n.m. n.m. 200 (46%) 370 (88%)
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write_8192 380 (99%) 370 (97%) n.m. n.m. 200 (45%) 320 (76%)
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rewrite_8192 490 (87%) 350 (66%) n.m. n.m. 200 (31%) 300 (46%)
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.TE
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* the operation of the hardware was suspect during these tests.
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.DE
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.PP
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The dropoff in reading and writing rates for the two drive SC780/Eagle
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tests are probably due to the file system using insufficient
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rotational delay for these tests.
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We have not fully investigated these times.
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.PP
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The following table compares data rates on VAX 11/750s directly
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with those of VAX 11/780s using the UDA50/RA81 storage system.
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.DS
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.TS
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box,center;
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c s s s s
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c s s s s
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c s s s s
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l | l s | l s
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l | l s | l s
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l | l l | l l
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l | c c | c c.
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4.2BSD File Systems Tests - \fBDEC UDA50 - 750 vs. 780\fR
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=
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Logically Sequential Transfers
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from an \fB8K/1K\fR 4.2BSD File System (Kbytes/sec.)
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_
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Test VAX 11/750 UNIBUS VAX 11/780 UNIBUS
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1 Drive 2 Drives 1 Drive 2 Drives
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_
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read_8192 310 (44%) 520 (84%) 360 (45%) 540 (72%)
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write_4096 370 (97%) 360 (100%) 380 (99%) 480 (96%)
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write_8192 320 (71%) 410 (96%) 220 (58%)* 480 (92%)
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rewrite_8192 310 (50%) 450 (80%) 220 (50%)* 180 (52%)*
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=
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.T&
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c s s s s
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c s s s s
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l | l s | l s
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l | l s | l s
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l | l l | l l
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l | c c | c c.
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Logically Sequential Transfers
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from an \fB4K/1K\fR 4.2BSD File System (Kbytes/sec.)
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_
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Test VAX 11/750 UNIBUS VAX 11/780 UNIBUS
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1 Drive 2 Drives 1 Drive 2 Drives
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_
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read_8192 210 (42%) 342 (77%) n.m. n.m.
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write_4096 215 (67%) 294 (99%) n.m. n.m.
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write_8192 215 (65%) 305 (98%) n.m. n.m.
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rewrite_8192 227 (47%) 336 (78%) n.m. n.m.
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.TE
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* the operation of the hardware was suspect during these tests.
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.DE
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.PP
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The higher throughput available on VAX 11/780s is due to a number
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of factors.
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The larger main memory size allows a larger file system cache.
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The block allocation routines run faster, raising the upper limit
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on the data rates in writing new files.
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.PP
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The next table makes the same comparison using an Emulex controller
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on both systems.
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.DS
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.TS
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box, center;
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c s s s s
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c s s s s
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c s s s s
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l | l s | l s
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l | l s | l s
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l | l l | l l
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l | c c | c c.
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4.2BSD File Systems Tests - \fBEmulex - 750 vs. 780\fR
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=
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Logically Sequential Transfers
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from an \fB8K/1K\fR 4.2BSD File System (Kbytes/sec.)
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_
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Test VAX 11/750 CMI Bus VAX 11/780 SBI Bus
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1 Drive 2 Drives 1 Drive 2 Drives
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_
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read_8192 490 (69%) 620 (96%) 560 (70%) 480 (58%)
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write_4096 380 (99%) 370 (99%) 440 (98%) 440 (98%)
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write_8192 470 (99%) 470 (99%) 490 (98%) 490 (98%)
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rewrite_8192 650 (99%) 620 (99%) 760 (100%) 560 (72%)
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=
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.T&
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c s s s s
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c s s s s
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l | l s | l s
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l | l s | l s
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l | l l | l l
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l | c c | c c.
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Logically Sequential Transfers
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from an \fB4K/1K\fR 4.2BSD File System (Kbytes/sec.)
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_
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Test VAX 11/750 CMI Bus VAX 11/780 SBI Bus
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1 Drive 2 Drives 1 Drive 2 Drives
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_
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read_8192 300 (60%) 400 (84%) 490 (77%) 370 (66%)
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write_4096 320 (98%) 320 (98%) 380 (98%) 370 (98%)
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write_8192 340 (98%) 340 (99%) 380 (99%) 370 (97%)
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rewrite_8192 450 (99%) 450 (98%) 490 (87%) 350 (66%)
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.TE
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.DE
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.PP
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The following table illustrates the evolution of our testing
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process as both hardware and software problems effecting
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the performance of the Emulex SC780 were corrected.
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The software change was suggested to us by George Goble
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of Purdue University.
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.PP
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The 4.2BSD handler for RH750/RH780 interfaced disk drives
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contains several constants which to determine how
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much time is provided between an interrupt signaling the completion
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of a positioning command and the subsequent start of a data transfer
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operation. These lead times are expressed as sectors of rotational delay.
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If they are too small, an extra complete rotation will often be required
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between a seek and subsequent read or write operation.
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The higher bit rate and rotational speed of the 2351A Fujitsu
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disk drives required
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increasing these constants.
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.PP
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The hardware change involved allowing for slightly longer
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delays in arbitrating for cycles on the SBI bus by
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starting the bus arbitration cycle a little further ahead of
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when the data was ready for transfer.
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Finally we had to increase the rotational delay between consecutive
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blocks in the file because
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the higher bandwidth from the disk generated more memory contention,
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which slowed down the processor.
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.DS
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.TS
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box,center,expand;
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c s s s s s s
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c s s s s s s
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c s s s s s s
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l | l s | l s | l s
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l | l s | l s | l s
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l | l s | l s | l s
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l | c c | c c | c c
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l | c c | c c | c c.
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4.2BSD File Systems Tests - \fBEmulex SC780 Disk Controller Evolution\fR
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=
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Logically Sequential Transfers
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from an \fB8K/1K\fR 4.2BSD File System (Kbytes/sec.)
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_
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Test Inadequate Search Lead OK Search Lead OK Search Lead
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Initial SBI Arbitration Init SBI Arb. Improved SBI Arb.
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1 Drive 2 Drives 1 Drive 2 Drives 1 Drive 2 Drives
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_
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read_8192 320 370 440 (60%) n.m. 560 (70%) 480 (58%)
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write_4096 250 270 300 (63%) n.m. 440 (98%) 440 (98%)
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write_8192 250 280 340 (60%) n.m. 490 (98%) 490 (98%)
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rewrite_8192 250 290 380 (48%) n.m. 760 (100%) 560 (72%)
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=
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.T&
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c s s s s s s
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c s s s s s s
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l | l s | l s | l s
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l | l s | l s | l s
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l | l s | l s | l s
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l | c c | c c | c c
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l | c c | c c | c c.
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Logically Sequential Transfers
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from an \fB4K/1K\fR 4.2BSD File System (Kbytes/sec.)
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_
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Test Inadequate Search Lead OK Search Lead OK Search Lead
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Initial SBI Arbitration Init SBI Arb. Improved SBI Arb.
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1 Drive 2 Drives 1 Drive 2 Drives 1 Drive 2 Drives
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_
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read_8192 200 220 280 n.m. 490 (77%) 370 (66%)
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write_4096 180 190 300 n.m. 380 (98%) 370 (98%)
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write_8192 180 200 320 n.m. 380 (99%) 370 (97%)
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rewrite_8192 190 200 340 n.m. 490 (87%) 350 (66%)
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.TE
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.DE
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.ds RH Conclusions
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.bp
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