GA-H77-DS3H memory errors with all slots filled

[motechman]

I have a Gigabyte system (GA-H77-DS3H) running Windows 7 that suddenly developed very erratic behavior and reboots frequently. It has 4 sticks of 2GB.

I booted a rescue CD and ran memtest86 and with all memory in place immediately reports lots of errors. If I remove half of the memory no errors are found.

So I figured it was just a memory failure. However, if I put the 2 SIMMs I removed intro the system in place of the other 2 (only 2 in system) and it passed without any errors. I can see the errors repeatedly whenever all slots are filled but none when only 2 are filled, no matter which individual SIMMs are installed.

So I am doubtful it's the RAM.

Can anyone shed any light on how to determine if it's the RAM or mobo?

Thanks much.

 

[BerylLee]

wondering your memory brand model spec .. and bios version

 

[motechman]

wondering your memory brand model spec .. and bios version

The BIOS version is F5, and the memory is Crucial Ballistix. I looked it up online and it is one of the recommended memory types.

 

[motechman]

I swapped the memory with another identical machine and ran memtest86 on it. The failure moved with the memory and adding the good memory from the known good system resulted in passing the memtest86 test on the "bad" machine.

Looks definitively like the RAM (all 4 sticks) has gone bad. I checked the BIOS settings which have the voltage set at 1.5 volts and the speed as "auto". Interestingly the speed on the auto setting was only 1300MHz rather than the rated 1600MHz of the memory. Didn't check what auto did on the good machine.

In all my decades of IT work I've never seen an entire bank of 4 SIMMs going bad at once unless there's a bunch of hardware swapping going on or the motherboard settings were incorrect. That is not the case with this system.

 

[Calvin7]

What is the part number of the memory and CPU?

 

[motechman]

What is the part number of the memory and CPU?

I have no idea what the part numbers are. I just sent the memory back to Crucial for an exchange. Until it arives I don't plan on going in to their office.

Since you're tagged as being the mobo expert, I'll defer to you. However it does strike me as a bit unusual to ask about the part numbers, unless this is a specific manufacturing problem or part compatibility issue.

I do appreciate your reply though.

 

[Calvin7]

If you are combining multiple kits of two to make four DIMMs then that is a configuration which is not guaranteed to work, which was why I inquired about the part number.

 

[motechman]

If you are combining multiple kits of two to make four DIMMs then that is a configuration which is not guaranteed to work, which was why I inquired about the part number.

I'm not sure I understand. Are you saying the design doesn't allow all 4 slots to be populated, or that 8GB comprised or four 2GB SIMMs isn't a valid configuration?

The later is how my predecessor configured the two systems and the former seems unlikely given the maximum amount of RAM the board supports.

Can you be more specific as to part number requirements? i.e if certain mobos had specific restrictions that other revisions didn't etc...

 

[Calvin7]

Memory is sold in kits. Combining kits, regardless of brand or model, is not recommended and is not guaranteed to work. Compatibility is guaranteed within each specific kit.

By mixing memory kits together, there may be compatibility issues such as unable to boot or unable to operate at rated specifications.

 

[motechman]

Memory is sold in kits. Combining kits, regardless of brand or model, is not recommended and is not guaranteed to work. Compatibility is guaranteed within each specific kit.

By mixing memory kits together, there may be compatibility issues such as unable to boot or unable to operate at rated specifications.

I received the memory from Crucial (warranty replacements) today. The system seems to be running well now and no problems are showing up in the event log. Perhaps the memory was just defective from the get go...