Help! Ram issues on a lenovo p50 laptop

[Arethusa]

I have a lenovo p50 i7-6700hq that has expandability up to 64gb with 4 sodimms. When i got the laptop it had 2x 8gb 2133hz samsung ddr4. I ordered 2 more sticks of killisre 8gb 2666, and when i installed them, the machine wouldn't post. Here is what Ive done so far to troubleshoot:

 

1) i added only 1 stick of killisre ram rather than 2 and the machine posted. I thought this might be because the one stick was defective, but i swapped them and the machine still posted. so both ram sticks are definately working. 

2) i then thought maybe the socket was busted, so i switched which slot the single stick of killisre was seated in. But to my suprise the machine still posted, so this wasnt the problem either. 

3) I then removed the samsung memory and seated both sticks of killisre memory in their place (total of 2), and the machine posted, after adding one stick of samsung memory the machine posted (total of 3), but adding the second samsung stick the machine wouldnt post (total of 4)

 

So it seems that no matter what orientation ive arrange the dimms, as soon as i add a 4rth module the machine wont post. The machine will only posted with a max of three modules. I even tried a 4gb stick of samsung ddr4 2133hz, 16gb crucial 2400hz dimm, and the same result. 

 

I am at a loss of what to do, right now i am updating the bios to see if there's any chance that could be the issue. Any help or ideas i could try would be appreciated. 

 

EDIT: Updating BIOS doesn't resolve the issue.

Edited December 5, 2022 by Arethusa
update

[Cyberat]

You're mix matching paired ram, but it is possible the laptop is not outputting enough voltage to run all 4 slots at once.

I'd stick to samsung memory and RMA the others, just cause it's an unknown brand of questionable quality.

Can you up the RAM voltage in Bios or is your Bios locked ? What are your voltage readings vs. specs. when 3 slots are full ?

What are the voltage specs. on the different RAM sticks ?

 

[Arethusa]

1 hour ago, Cyberat said:

You're mix matching paired ram, but it is possible the laptop is not outputting enough voltage to run all 4 slots at once.

I'd stick to samsung memory and RMA the others, just cause it's an unknown brand of questionable quality.

Can you up the RAM voltage in Bios or is your Bios locked ? What are your voltage readings vs. specs. when 3 slots are full ?

What are the voltage specs. on the different RAM sticks ?

 

Thanks for the reply, I am starting the RMA process and I do agree with you, I should stick to well known RAM. There is probably just something happening with mixing of dimms and the timings.

 

Here are the voltage specs:

Kllisre: 1.2v

Samsung: 1.2v

 

CPU-Z is showing same voltage as the specs.

 

I also thought maybe I could've been mixing ECC and non-ECC, but I've ruled that out too.

 

[Cyberat]

Registered and non-registered ?

But can you look at voltage under BIOS ? Does it consistently stay under 1.2V ?

Otherwise you will get little to no performance bonus running 2400mhz vs 2133mhz.

Watch Linus' video on performance gain vs ram speed.

[Arethusa]

Just in case anyone searches this thread and has some problem with their p50, I was able to get it running by arranging the dimms so they run in series/same channels.

 

Theres two ram slots under the keyboard and two on the underside of the laptop. However if your mixing dimms, the top slot under the keyboard has to have the same type of memory as the bottom slot on the underside. 

 

I thought I already tested that configuration, but after trying again, it worked! 

 

All four dimms clocked down to 2133mhz because that's the max supported by the CPU.