T5500 workstation should I testator hyper threading enabled?

[Chamjisky]

Hi
I enabled hyper threading but memtest is only recognizing 4 cpus for my single processor quad core processor E5620.

Does it affects test outcome esp if round Robin is selected.

Regards

[David (PassMark)]

In terms of testing the RAM it shouldn't have much impact.

[Chamjisky]

In terms of testing the RAM it shouldn't have much impact.

So using all cores in parallel would neither hide any errors nor induce any false error?

Also does it increases the testing speed? Under which circumstances?

If a cpu has 4 cores and 8 threads does it shows 8 cores or 4 cpus /obviously ht is enabled from bios.

Thanks

[David (PassMark)]

Hyperthreaded cores share the same memory bus. Some while I haven't taken any exact measurements, it would be surprising if hyperthreading had any significant impact on the test speed.

What does make a different is moving from single core testing to multi-core testing. Multi-core testing is significantly faster, but there is a point of dimishing returns. i.e. moving from 1 core to 2 cores gives a much bigger speed increase compared to moving from 4 cores to 5 cores.

In terms of error detection, generally the result should be the same. However running all core does increase the temperature of the system and also changes the memory access patterns, as all the cores are running asynchronously. So from time to time you might get different results from running on all cores.

[Chamjisky]

Hyperthreaded cores share the same memory bus. Some while I haven't taken any exact measurements, it would be surprising if hyperthreading had any significant impact on the test speed.

What does make a different is moving from single core testing to multi-core testing. Multi-core testing is significantly faster, but there is a point of dimishing returns. i.e. moving from 1 core to 2 cores gives a much bigger speed increase compared to moving from 4 cores to 5 cores.

In terms of error detection, generally the result should be the same. However running all core does increase the temperature of the system and also changes the memory access patterns, as all the cores are running asynchronously. So from time to time you might get different results from running on all cores.

Hmm.
I have an issue with my t5500 workstation.

I purchased it without ram. Then I purchased 6 sticks each of 8gb ddr3 ecc registered ram.
All rams were ok (one pass) when each was tested separately.

But when I install all at the same time. It hangs.
I did below testing.

Install all rams and run test using default settings.
It passed one pass and second pass was running when checked after 13 hours.

Tried again it would hang after one hours or so. The cursor just above esc exit was blinking but the time was not updated for past 6 hours as it was left overnight and in time it should have shown 8 hours but it was showing 3 hours. Also keyboard was not responding.

Tried testing all 48gb with 4 cores in parallel
mode it passed one cycle and hanged like above after 40%. Test was run overnight. In morning it should have shown time as 8 hours but it was showing 3 hours and 36 minutes.


Tested with prime 95 using small ffts for 5hours with 8gb ram single stick no hang in Windows.


Tested again with prime 95 using small ffts for 5hours with 40gb ram 5x 8gb sticks no hang in Windows.

Tried swapping the sixth ram still no issue. Seems when I install all 6 sticks its behavior becomes erratic.

[keith]

Does it hang in single CPU mode as well?

Can you upload or e-mail us the MemTest86.log under the EFI\BOOT\ directory of the USB flash drive.

[Chamjisky]

No such file exists.
Searched entire usb no file with extension of log was found.

When it hanged the cpu ticks were not changing /animating and the time also did not changed even after leaving it for few hours.
Mouse keyboard were not responding. I have to press power button for few seconds to power it off.
But there is a little cursor almost few inches above status bar where is says escape exit. It was blinking.

[keith]

What version of MemTest86 are you using?

Because the log file does not exist, I assume that you are not running the newer MemTest86 v6. Does your system support UEFI?

[Chamjisky]

What version of MemTest86 are you using?

Because the log file does not exist, I assume that you are not running the newer MemTest86 v6. Does your system support UEFI?

Yes I am using latest version. I don't think dell t5500 supports efi bios.
Memtest86 is showing version 4.3.7
I also have uploaded a video of it.
https://youtu.be/6JJKCFD5Hso