Memory Thrashing

[storm5510]

Is there any definite way to detect memory thrashing?

When Prime95 is running P-1 or ECM, it runs for two seconds and pauses for one second. I have tried different memory settings from 256M to 1024M. This has no affect.

Ideas?

[xilman]

Originally Posted by storm5510

Is there any definite way to detect memory thrashing?

When Prime95 is running P-1 or ECM, it runs for two seconds and pauses for one second. I have tried different memory settings from 256M to 1024M. This has no affect.

Ideas?

Use top(1) or the equivalent (<blah> Manager in Windows, where I thing <blah> is Task but I may be wrong) to see whether the active virtual memory used by Prime95 is comparable with, or greater than, the amount of physical memory (or assigned memory if you are running in a virtual machine).

Thrashing is often indicated by excessive disk activity, so take a look at the blinkenlights if you have them on your machine.

[storm5510]

Originally Posted by xilman

Use top(1) or the equivalent (<blah> Manager in Windows, where I thing <blah> is Task but I may be wrong) to see whether the active virtual memory used by Prime95 is comparable with, or greater than, the amount of physical memory (or assigned memory if you are running in a virtual machine).

Thrashing is often indicated by excessive disk activity, so take a look at the blinkenlights if you have them on your machine.

I am unsure we are writing about the same thing. Excessive disk activity usually indicates paging, or swap, file activity. I do not see any of this. I do not run any VM's.

[axn]

Originally Posted by storm5510

Excessive disk activity usually indicates paging, or swap, file activity.

aka memory trashing... What else did you mean when you said memory thrashing?

[storm5510]

Originally Posted by axn

aka memory trashing... What else did you mean when you said memory thrashing?

If RAM and HD are the same in this context, then there is no other meaning.

I have the day/night RAM setting at the minimum required to do P-1 tests. 512MB. That is where I will leave it.

As for the stop/start cycles, it is possible other things could be involved, given the nature of Windows 10 behavior at times.

[VBCurtis]

Originally Posted by storm5510

If RAM and HD are the same in this context, then there is no other meaning.

Huh? What context? In what way are RAM and HD the same?
Are you really saying that P-1 is accessing memory a lot, the way someone else who says "memory thrashing" means "lots of memory being paged to disk"?

I'm afraid we're not following what you are trying to say. Can you spell it out?

[paulunderwood]

Disk thrashing occurs when pages are swapped in to and out of secondary storage, when the primary storage is not big enough to hold all activity. Thrashing, I guess, must refer to the read/write head going berserk.

[science_man_88]

Originally Posted by paulunderwood

Disk thrashing occurs when pages are swapped in to and out of secondary storage, when the primary storage is not big enough to hold all activity. Thrashing, I guess, must refer to the read/write head going berserk.

from Wikipedia:

In computer science, thrashing occurs when a computer's virtual memory subsystem is in a constant state of paging, rapidly exchanging data in memory for data on disk, to the exclusion of most application-level processing.[1] This causes the performance of the computer to degrade or collapse. The situation may continue indefinitely until the underlying cause is addressed.

The term is also used for various similar phenomena, particularly movement between other levels of the memory hierarchy, where a process progresses slowly because significant time is being spent acquiring resources.

[VBCurtis]

Originally Posted by paulunderwood

Disk thrashing occurs when pages are swapped in to and out of secondary storage, when the primary storage is not big enough to hold all activity. Thrashing, I guess, must refer to the read/write head going berserk.

Yep! But OP seems to think there is a similar item for "memory thrashing"; he said (in post 3) his disk isn't getting hit much. That's what I am confused about.

[xilman]

Originally Posted by VBCurtis

Yep! But OP seems to think there is a similar item for "memory thrashing"; he said (in post 3) his disk isn't getting hit much. That's what I am confused about.

As am I.

[science_man_88]

Originally Posted by VBCurtis

Yep! But OP seems to think there is a similar item for "memory thrashing"; he said (in post 3) his disk isn't getting hit much. That's what I am confused about.

could be ( again using wikipedia, same page actually):

cache thrashing
TLB ( translation lookaside buffer) thrashing
Heap thrashing
process thrashing

at least by the same naming scheme.