Third ram?

[Criticalmeadow]

I have 2 x 16 gigs of ram, I also have a third ram stick of the same type, I was hoping to have 3 sticks of ram for my computer, but when I tried, it was very unstable and would crash and blue screen frequently. Does anyone have any clue if this is possible?

[matt0725]

Mixing ram that didnt come from the same package all together can cause instability. What system is this? ddr4 or ddr5?

 

Plus, using 3 sticks may put your memory into single channel mode rather than dual, and that will get you worse performance(still more ram, just slower), but im not 100% sure on that part.

[CommanderAlex]

The problem is your 2x16GB kit will be running in dual channel, with the 3rd stick running single channel. Combine that with possibly different IC chips, memory size, memory speed and timings; yes it's going to cause crashing/freezing/BSOD. 

[Zando_]

Definitely, some DIMMs don't get along with each other. On most systems you won't want to run 3 sticks of RAM anyways. There are some HEDT CPUs that support triple channel, but not common mainstream ones. 

1 minute ago, matt0725 said:

Plus, using 3 sticks may put your memory into single channel mode rather than dual, and that will get you worse performance(still more ram, just slower), but im not 100% sure on that part.

As I understand it, it will run the first 2 sticks in dual channel, and the 3rd in single, so once you get to that stick there'll be a slowdown. The instability is likely just different ICs and such as @CommanderAlexpointed out. 

[Vishera]

33 minutes ago, CommanderAlex said:

The problem is your 2x16GB kit will be running in dual channel, with the 3rd stick running single channel. Combine that with possibly different IC chips, memory size, memory speed and timings; yes it's going to cause crashing/freezing/BSOD. 

Only platforms that support Intel Flex Mode can be fine with DIMMs of different sizes.

The last time i used this was in 2011 on a Sandy Bridge CPU.

I paired a 4GB DIMM with a 2GB DIMM and run them with Intel Flex Mode.

Though i am not sure how Intel Flex Mode handles a third DIMM and whether it's supported on the platform you are using or supported at all.

[SupaKomputa]

Check the motherboard manual, you will need to put the third module in the correct slot or it wont work. (especially for Ryzen, idk about intel).

 

[Somerandomtechyboi]

 

Meanwhile i can get to 80% of the ddr2 wr (1520) p95 large ffts stable in a goofy ass 1x3 config, though these sticks are the same ic so unsurprising they work fine

 

Pretty sure you just have different ics that hate each other, and yes the 3rd stick will run in single channel but the 2 other sticks will be dual channel since the first 32gb are in 2 diff channels, the last 16gb are in single channel cause there isnt a stick on the other channel to accompany it, but if you need the extra ram itll still be faster than a crappy pagefile

[avidgamer121]

1 hour ago, CommanderAlex said:

The problem is your 2x16GB kit will be running in dual channel, with the 3rd stick running single channel. Combine that with possibly different IC chips, memory size, memory speed and timings; yes it's going to cause crashing/freezing/BSOD. 

i fall under all those criteria since ddr3 era (or possibly ever since my first pc in 2007 with which initially came with 512mb ram to which i later added 1gb stick) and yet encounter anything like that,

[CommanderAlex]

15 minutes ago, xdagamer said:

i fall under all those criteria since ddr3 era (or possibly ever since my first pc in 2007 with which initially came with 512mb ram to which i later added 1gb stick) and yet encounter anything like that,

Perhaps at JEDEC timings it ran at, but not XMP.

[Criticalmeadow]

4 hours ago, matt0725 said:

Mixing ram that didnt come from the same package all together can cause instability. What system is this? ddr4 or ddr5?

 

Plus, using 3 sticks may put your memory into single channel mode rather than dual, and that will get you worse performance(still more ram, just slower), but im not 100% sure on that part.

Ddr4, they are all Gskill ripjaw ram with xmp 2.0