Apple Server Diagnostics - Memory Tests

background image

Memory Tests

All memory tests are listed under Memory. These tests are described here.

An ECC error count test is automatically run after these tests complete.

Simple Memory Tests

Simple memory tests test the first 2.5 GB of memory. To test all memory, run extended
memory tests.

background image

46

Appendix

Server Diagnostics Test Reference

Even though simple memory tests don’t test all memory, you can run these tests to
detect intermittent memory issues.

In Server Diagnostics EFI, all memory tests (simple, multicore, and extended) are
grouped under Memory tests.

Note: The time required to complete memory tests correlates to the amount of
memory being tested. These estimates are based on testing 2 GB of memory.

Test

Estimated completion time

Description

Address as Data

5 seconds

Tests memory using the
memory address as data.

Patterns

10 seconds

Tests memory using different
data patterns.

Marching Ones and Zeros

10 seconds

Tests memory by walking 1s and
0s up and down memory.

Knaizuk Hartmann

5 seconds

Tests memory using this
algorithm.

MOD3

15 seconds

Tests memory using this
algorithm.

March U

1 minute

Tests memory using Van de
Goor’s March U algorithm.

Random

15 seconds

Uses pseudo-random values.

Block Checkerboard 32

5 seconds

Alternates 32-bit words with all
1s and all 0s, and then with all
0s and all 1s.

Bit Checkerboard 32

5 seconds

Alternates bits with all 1s and
all 0s, and then with all 0s and
all 1s.

Sequential Byte Block 32

9 minutes

Fills all bytes sequentially with
patterns starting at 0x00 and
ending at 0xFF.

Walking One 32

5 minutes

Walks 1s up and down memory.

Walking Zero 32

5 minutes

Walks 0s up and down memory.

Walking Spread Bit 32

5 minutes

Walks 0b01 up and then walks
0b10 down memory.

Walking Bit Flip 32

5 minutes

Alternates words with walking
1 and walking 0, and then
alternates with walking 0 and
walking 1.

background image

Appendix

Server Diagnostics Test Reference

47

Multicore Memory Tests

Multicore memory tests test the first 2.5 GB of memory using all available CPU cores.

In Server Diagnostics EFI, all memory tests (simple, multicore, and extended) are
grouped under Memory tests.

Note: The time required to complete memory tests correlates to the amount of
memory being tested. These estimates are based on testing 1 GB of memory.

Test

Estimated completion time

Description

MP Block Checkerboard

5 seconds

Alternates 32-bit words with all
1s and all 0s, and then with all
0s and all 1s.

MP Bit Checkerboard

5 seconds

Alternates bits with all 1s and
all 0s, and then with all 0s and
all 1s.

MP Sequential Byte Block

8 minutes

Fills all bytes sequentially with
patterns starting at 0x00 and
ending at 0xFF.

MP Walking One

2 minutes

Walks 1s up and down memory.

MP Walking Zero

4 minutes

Walks 0s up and down memory.

MP Walking Spread Bit

4 minutes

Walks 0b01 up and then walks
0b10 down memory.

MP Walking Bit Flip

4 minutes

Alternates words with walking
1 and walking 0, and then
alternates words with walking 0
and walking 1.

Check Hardware Errors

1 second

Tests specific registers for
memory related errors. Running
this test at the end of memory
testing may help catch memory
errors generated during other
memory tests.

Extended Memory Tests

Extended memory tests test all available memory.

In Server Diagnostics EFI, all memory tests (simple, multicore, and extended) are
grouped under Memory tests.

The availability of extended memory tests depends on the server model you test.

Note: The time required to complete memory tests correlates to the amount of
memory being tested. These estimates are based on testing 1 GB of memory.

background image

48

Appendix

Server Diagnostics Test Reference

Test

Estimated completion time

Description

Extended Memory Test P00F

5 seconds

Tests memory using pattern 0.
This fails if an error occurs.

Extended Memory Test P01F

5 seconds

Tests memory using pattern 1.
This fails if an error occurs.

Extended Memory Test P02F

5 seconds

Tests memory using pattern 2.
This fails if an error occurs.

Extended Memory Test P03F

5 seconds

Tests memory using pattern 3.
This fails if an error occurs.

Extended Memory Test P04F

5 seconds

Tests memory using pattern 4.
This fails if an error occurs.

Extended Memory Test P05F

5 seconds

Tests memory using pattern 5.
This fails if an error occurs.

Extended Memory Test P06F

5 seconds

Tests memory using pattern 6.
This fails if an error occurs.

Extended Memory Test P07F

5 seconds

Tests memory using pattern 7.
This fails if an error occurs.