Where is the fault?

[Chamjisky]

Hi,
I have dell t5500 workstation using e5620 single processor...
I installed 8 ram sticks each of 8gb. And it would hang intermittently in Windows no issue in hdd or os as tried another ok ok hdd with fresh os.

I tested each stick separately for 3 passes and no issue found on any stickstick.

I install 3 sticks again no issue. Tried 6 passes no hang out whatsoever in memtest 86. All counters were running and cpu /\|/ thingy was animating.

Them I tested the remaining three at same time no issue.

But when all 6 sticks are installed it hangs and the counters do not increment even if left for 6 hours.

What could be issue?not over clocked. Using latest bios. No ram tweaks. All rams are of same type and manufacturer.

[Chamjisky]

Does this mean ram is for bit motherboard is problematic

[David (PassMark)]

What version of MemTest86 are you using?

[Chamjisky]

What version of MemTest86 are you using?

Using latest version but it's showing as 4.3.7
T5500 doesn't support support the newer bios types..

[David (PassMark)]

I assume the machine actually supports 64GB of RAM?

Maybe is it a bad motherboard slot. Can you test 3 sticks in slots 4 to 6 (assuming you were previously testing slots 1 to 3).

Does the CPU/motherboard support dual, tri or quad channel RAM. If it only supports dual channel, then try testing 2 sticks at a time. Switch between single channel and dual channel mode will change the access pattern and might provoke / hide errors.

Does the BIOS allow you to play around with the RAM voltages / speeds? Can you lower the speeds or very slightly increase the voltage as an experiment.

Also are you running the latest BIOS. It is very very common for new BIOSs to improve memory compatibility.

[Chamjisky]

I assume the machine actually supports 64GB of RAM?

Maybe is it a bad motherboard slot. Can you test 3 sticks in slots 4 to 6 (assuming you were previously testing slots 1 to 3).

Does the CPU/motherboard support dual, tri or quad channel RAM. If it only supports dual channel, then try testing 2 sticks at a time. Switch between single channel and dual channel mode will change the access pattern and might provoke / hide errors.

Does the BIOS allow you to play around with the RAM voltages / speeds? Can you lower the speeds or very slightly increase the voltage as an experiment.

Also are you running the latest BIOS. It is very very common for new BIOSs to improve memory compatibility.

This is dell t5500 workstation. Maximum ram officially supported is 72gb worth riser card. And 48gb without it .

Its in tri channel configuration.

No settings in bios for ram voltages etc. No overclocking.

Using latest bios.

I first tried three sticks in dim 123 no issue. Then the other triplet in same slots for 6 passes no issue. Then I tried ram 123 in slot 123 and ram 45 in slot 4-5.no issue .then i changed ram 4-5 to slot 56 while 123 were still occupied by ram123. No issue.
Then I swapped stick 1 with stick6 no issue.

[David (PassMark)]

Doesn't really make sense to me that you have 8 RAM sticks and the CPU is tri channel. You should have either 3, 6, 9 or 12 memory sticks, depending on what the board supports.

It might just be incompatibility between the motherboard and RAM. For example a slight voltage drop when 8 sticks are installed, or loss of signal integrity.

You might want to ask Dell if they have a list of qualify RAM models that they have tested and know that work.

[Chamjisky]

Doesn't really make sense to me that you have 8 RAM sticks and the CPU is tri channel. You should have either 3, 6, 9 or 12 memory sticks, depending on what the board supports.

It might just be incompatibility between the motherboard and RAM. For example a slight voltage drop when 8 sticks are installed, or loss of signal integrity.

You might want to ask Dell if they have a list of qualify RAM models that they have tested and know that work.

It has 6 sticks. As explained in previous post.
Yesterday I removed the fan and heatsinks as it was wiggling when touched from one cornercorner of heat sink. Seemed like it's just left lying on that chip. When the heatsink was removed there was thermal pad and it was not sticking to chip. Since I do not have a thermal pad so I just applied generic heatsink compound over the pad.

Now all six sticks are on testing for the past 18 hours and 5 passes have passed without any error..

How many passes more should I let it run for? Currently it's in parallel mode.

I hope the issue might be due to that heatsink sitting loose on the chip..
Once all tests pass I will buy quality thermal paste and apply it.

[David (PassMark)]

It has 6 sticks. As explained in previous post.

Maybe it was a typo, but your first post said, "I installed 8 ram sticks each of 8gb."

I would think that an 18h test would be sufficient.