What is Memtest86+ “failsafe” mode for?
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When starting Memtest86+ version 5.01, there is a blinking message:
==> Press F1 to enter Fail-Safe Mode <==
If I hit F1 there is the usual progression screen, except that the RAM information (freq, timings ...) is replaced by the message:
**** FAIL SAFE **** **** FAIL SAFE ****
No Detection, same reliability
So I understand that memory errors are not detected and that the computer is only stress-tested (which could be useful to test if CPU is good when we now that the RAM is faulty). Am I right ? There is little information about this on the website.
memtest86+
asked Jan 28 at 23:55
Gabriel DevillersGabriel Devillers
29339
add a comment |
When starting Memtest86+ version 5.01, there is a blinking message:
==> Press F1 to enter Fail-Safe Mode <==
If I hit F1 there is the usual progression screen, except that the RAM information (freq, timings ...) is replaced by the message:
**** FAIL SAFE **** **** FAIL SAFE ****
No Detection, same reliability
So I understand that memory errors are not detected and that the computer is only stress-tested (which could be useful to test if CPU is good when we now that the RAM is faulty). Am I right ? There is little information about this on the website.
memtest86+
asked Jan 28 at 23:55
Gabriel DevillersGabriel Devillers
29339
add a comment |
When starting Memtest86+ version 5.01, there is a blinking message:
==> Press F1 to enter Fail-Safe Mode <==
If I hit F1 there is the usual progression screen, except that the RAM information (freq, timings ...) is replaced by the message:
**** FAIL SAFE **** **** FAIL SAFE ****
No Detection, same reliability
So I understand that memory errors are not detected and that the computer is only stress-tested (which could be useful to test if CPU is good when we now that the RAM is faulty). Am I right ? There is little information about this on the website.
memtest86+
asked Jan 28 at 23:55
Gabriel DevillersGabriel Devillers
29339
When starting Memtest86+ version 5.01, there is a blinking message:
==> Press F1 to enter Fail-Safe Mode <==
If I hit F1 there is the usual progression screen, except that the RAM information (freq, timings ...) is replaced by the message:
**** FAIL SAFE **** **** FAIL SAFE ****
No Detection, same reliability
So I understand that memory errors are not detected and that the computer is only stress-tested (which could be useful to test if CPU is good when we now that the RAM is faulty). Am I right ? There is little information about this on the website.
memtest86+
memtest86+
asked Jan 28 at 23:55
Gabriel DevillersGabriel Devillers
29339
asked Jan 28 at 23:55
Gabriel DevillersGabriel Devillers
29339
asked Jan 28 at 23:55
Gabriel DevillersGabriel Devillers
29339
asked Jan 28 at 23:55
Gabriel DevillersGabriel Devillers
29339
asked Jan 28 at 23:55
Gabriel DevillersGabriel Devillers
29339
29339
add a comment |
add a comment |
1 Answer
1
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According to the source code:
/* F1 */
if(c == scs) v->fail_safe
Pressing F1 sets the fail_safe 1 bit (same variable is used for other things as well), and then...
/* Find Memory Specs */
if(v->fail_safe & 1)
cprint(LINE_CPU, COL_SPEC, " **** FAIL SAFE **** FAIL SAFE **** ");
cprint(LINE_RAM, COL_SPEC, " No detection, same reliability ");
else
find_controller();
get_spd_spec();
if(num_cpus <= 16 && !(v->fail_safe & 4)) coretemp();
...it skips the "find memory specs" step. Basically this detects what type of memory you have (DDR3, DDR4, ECC, clock speed, etc.) which memtest86+ usually displays on the right hand side.
Why is it called failsafe? My guess it's because memtest86+ operates on a very low level and a single wrong step would cause it to crash entirely. So maybe doing this detection step crashes some systems, and by pressing F1 maybe you can get past that crash and still use the program.
I have also found some old posts in the Memtest86 forums asking about failsafe but zero answers.
http://forum.canardpc.com/threads/83104-Memtest86-5-01-(finally)-released?p=7066673
Tips : F1 will enable fail-safe mode, F2 will enable SMP Mode (disabled by default) and F3 will trigger an hidden alternative SMP Mode.
(From reading the source code, those are mutually exclusive, you can only pick one of them or wait for input timeout to commence regular operation.)
As long as the program works for you, I guess there is no need to worry about it.
answered Jan 29 at 0:18
frostschutzfrostschutz
669810
4
There are a few mentions on the web of memory modules with incorrect or corrupted SPD information - such that it can't be read, or if read, would be so badly wrong the board using that information to set memory timings wouldn't work (lock up, or read bad data, or something). So this is most likely a failsafe where it won't even try to read the SPD. Presumably you try to run memtest86 without it, it fails in some horrible way a couple of times, so then you try the failsafe mode.
– davidbak
Jan 29 at 19:13
add a comment |
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1 Answer
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1 Answer
1
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oldest
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votes
According to the source code:
/* F1 */
if(c == scs) v->fail_safe
Pressing F1 sets the fail_safe 1 bit (same variable is used for other things as well), and then...
/* Find Memory Specs */
if(v->fail_safe & 1)
cprint(LINE_CPU, COL_SPEC, " **** FAIL SAFE **** FAIL SAFE **** ");
cprint(LINE_RAM, COL_SPEC, " No detection, same reliability ");
else
find_controller();
get_spd_spec();
if(num_cpus <= 16 && !(v->fail_safe & 4)) coretemp();
...it skips the "find memory specs" step. Basically this detects what type of memory you have (DDR3, DDR4, ECC, clock speed, etc.) which memtest86+ usually displays on the right hand side.
Why is it called failsafe? My guess it's because memtest86+ operates on a very low level and a single wrong step would cause it to crash entirely. So maybe doing this detection step crashes some systems, and by pressing F1 maybe you can get past that crash and still use the program.
I have also found some old posts in the Memtest86 forums asking about failsafe but zero answers.
http://forum.canardpc.com/threads/83104-Memtest86-5-01-(finally)-released?p=7066673
Tips : F1 will enable fail-safe mode, F2 will enable SMP Mode (disabled by default) and F3 will trigger an hidden alternative SMP Mode.
(From reading the source code, those are mutually exclusive, you can only pick one of them or wait for input timeout to commence regular operation.)
As long as the program works for you, I guess there is no need to worry about it.
answered Jan 29 at 0:18
frostschutzfrostschutz
669810
4
There are a few mentions on the web of memory modules with incorrect or corrupted SPD information - such that it can't be read, or if read, would be so badly wrong the board using that information to set memory timings wouldn't work (lock up, or read bad data, or something). So this is most likely a failsafe where it won't even try to read the SPD. Presumably you try to run memtest86 without it, it fails in some horrible way a couple of times, so then you try the failsafe mode.
– davidbak
Jan 29 at 19:13
add a comment |
According to the source code:
/* F1 */
if(c == scs) v->fail_safe
Pressing F1 sets the fail_safe 1 bit (same variable is used for other things as well), and then...
/* Find Memory Specs */
if(v->fail_safe & 1)
cprint(LINE_CPU, COL_SPEC, " **** FAIL SAFE **** FAIL SAFE **** ");
cprint(LINE_RAM, COL_SPEC, " No detection, same reliability ");
else
find_controller();
get_spd_spec();
if(num_cpus <= 16 && !(v->fail_safe & 4)) coretemp();
...it skips the "find memory specs" step. Basically this detects what type of memory you have (DDR3, DDR4, ECC, clock speed, etc.) which memtest86+ usually displays on the right hand side.
Why is it called failsafe? My guess it's because memtest86+ operates on a very low level and a single wrong step would cause it to crash entirely. So maybe doing this detection step crashes some systems, and by pressing F1 maybe you can get past that crash and still use the program.
I have also found some old posts in the Memtest86 forums asking about failsafe but zero answers.
http://forum.canardpc.com/threads/83104-Memtest86-5-01-(finally)-released?p=7066673
Tips : F1 will enable fail-safe mode, F2 will enable SMP Mode (disabled by default) and F3 will trigger an hidden alternative SMP Mode.
(From reading the source code, those are mutually exclusive, you can only pick one of them or wait for input timeout to commence regular operation.)
As long as the program works for you, I guess there is no need to worry about it.
answered Jan 29 at 0:18
frostschutzfrostschutz
669810
4
There are a few mentions on the web of memory modules with incorrect or corrupted SPD information - such that it can't be read, or if read, would be so badly wrong the board using that information to set memory timings wouldn't work (lock up, or read bad data, or something). So this is most likely a failsafe where it won't even try to read the SPD. Presumably you try to run memtest86 without it, it fails in some horrible way a couple of times, so then you try the failsafe mode.
– davidbak
Jan 29 at 19:13
add a comment |
According to the source code:
/* F1 */
if(c == scs) v->fail_safe
Pressing F1 sets the fail_safe 1 bit (same variable is used for other things as well), and then...
/* Find Memory Specs */
if(v->fail_safe & 1)
cprint(LINE_CPU, COL_SPEC, " **** FAIL SAFE **** FAIL SAFE **** ");
cprint(LINE_RAM, COL_SPEC, " No detection, same reliability ");
else
find_controller();
get_spd_spec();
if(num_cpus <= 16 && !(v->fail_safe & 4)) coretemp();
...it skips the "find memory specs" step. Basically this detects what type of memory you have (DDR3, DDR4, ECC, clock speed, etc.) which memtest86+ usually displays on the right hand side.
Why is it called failsafe? My guess it's because memtest86+ operates on a very low level and a single wrong step would cause it to crash entirely. So maybe doing this detection step crashes some systems, and by pressing F1 maybe you can get past that crash and still use the program.
I have also found some old posts in the Memtest86 forums asking about failsafe but zero answers.
http://forum.canardpc.com/threads/83104-Memtest86-5-01-(finally)-released?p=7066673
Tips : F1 will enable fail-safe mode, F2 will enable SMP Mode (disabled by default) and F3 will trigger an hidden alternative SMP Mode.
(From reading the source code, those are mutually exclusive, you can only pick one of them or wait for input timeout to commence regular operation.)
As long as the program works for you, I guess there is no need to worry about it.
answered Jan 29 at 0:18
frostschutzfrostschutz
669810
According to the source code:
/* F1 */
if(c == scs) v->fail_safe
Pressing F1 sets the fail_safe 1 bit (same variable is used for other things as well), and then...
/* Find Memory Specs */
if(v->fail_safe & 1)
cprint(LINE_CPU, COL_SPEC, " **** FAIL SAFE **** FAIL SAFE **** ");
cprint(LINE_RAM, COL_SPEC, " No detection, same reliability ");
else
find_controller();
get_spd_spec();
if(num_cpus <= 16 && !(v->fail_safe & 4)) coretemp();
...it skips the "find memory specs" step. Basically this detects what type of memory you have (DDR3, DDR4, ECC, clock speed, etc.) which memtest86+ usually displays on the right hand side.
Why is it called failsafe? My guess it's because memtest86+ operates on a very low level and a single wrong step would cause it to crash entirely. So maybe doing this detection step crashes some systems, and by pressing F1 maybe you can get past that crash and still use the program.
I have also found some old posts in the Memtest86 forums asking about failsafe but zero answers.
http://forum.canardpc.com/threads/83104-Memtest86-5-01-(finally)-released?p=7066673
Tips : F1 will enable fail-safe mode, F2 will enable SMP Mode (disabled by default) and F3 will trigger an hidden alternative SMP Mode.
(From reading the source code, those are mutually exclusive, you can only pick one of them or wait for input timeout to commence regular operation.)
As long as the program works for you, I guess there is no need to worry about it.
answered Jan 29 at 0:18
frostschutzfrostschutz
669810
answered Jan 29 at 0:18
frostschutzfrostschutz
669810
answered Jan 29 at 0:18
frostschutzfrostschutz
669810
answered Jan 29 at 0:18
frostschutzfrostschutz
669810
669810
4
There are a few mentions on the web of memory modules with incorrect or corrupted SPD information - such that it can't be read, or if read, would be so badly wrong the board using that information to set memory timings wouldn't work (lock up, or read bad data, or something). So this is most likely a failsafe where it won't even try to read the SPD. Presumably you try to run memtest86 without it, it fails in some horrible way a couple of times, so then you try the failsafe mode.
– davidbak
Jan 29 at 19:13
add a comment |
4
There are a few mentions on the web of memory modules with incorrect or corrupted SPD information - such that it can't be read, or if read, would be so badly wrong the board using that information to set memory timings wouldn't work (lock up, or read bad data, or something). So this is most likely a failsafe where it won't even try to read the SPD. Presumably you try to run memtest86 without it, it fails in some horrible way a couple of times, so then you try the failsafe mode.
– davidbak
Jan 29 at 19:13
4
4
There are a few mentions on the web of memory modules with incorrect or corrupted SPD information - such that it can't be read, or if read, would be so badly wrong the board using that information to set memory timings wouldn't work (lock up, or read bad data, or something). So this is most likely a failsafe where it won't even try to read the SPD. Presumably you try to run memtest86 without it, it fails in some horrible way a couple of times, so then you try the failsafe mode.
– davidbak
Jan 29 at 19:13
There are a few mentions on the web of memory modules with incorrect or corrupted SPD information - such that it can't be read, or if read, would be so badly wrong the board using that information to set memory timings wouldn't work (lock up, or read bad data, or something). So this is most likely a failsafe where it won't even try to read the SPD. Presumably you try to run memtest86 without it, it fails in some horrible way a couple of times, so then you try the failsafe mode.
– davidbak
Jan 29 at 19:13
add a comment |
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