[SOLVED] can you mix different rams stick on a mobo?

anaturelover

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Jun 24, 2012
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i have for example this 12 g triple channel ram ddr3 3x4g
gig ram 12.0GB Triple-Channel DDR3 @ 534MHz (8-7-7-20) corsaire dominator cmp12gx3m3a1600c9 999-24 1,65 ver 2,12a 12gb 3x4gb 1600mhz

if i buy a b85 lga 1150 there will be one slot free. can i insert any other ddr3 ram size timing brand and other parameters.
GIGABYTE GA-B85-HD3,1150 SOCKET,DESKTOP COMPUTER MOTHERBOARD,DDR3,ATX,B85,HDMI,DVI,VGA https://spcpshop.com/products/gigab...-b85-hdmi-dvi-vga?_pos=2&_sid=8291bb8f9&_ss=r



how does that work ? tx
 
Solution
It MAY work without problems. No guarantees. You normally see only 4 timing parameters and a frequency posted for any particular RAM model. There are many more than that in Primary, secondary, and tertiary levels.

The 4 you normally see are the primary CAS Latency, tRCD, tRP, & tRAS
These would be the ones you see adjustable in a simple BIOS for example: 16-16-16-32 2T

Secondary timings would include tWR, tRFC, tRDD_L, tRDD_S, tWTR_L, tWTR_S, tRTP, tFAW, and tCWL
SOME motherboards expose these timings to tweaking as well, many won't of course for good reason.

Then you can get into the tertiary layer.

Your memory controller has to be able to synchronize all of that, which can be hard enough for 4 identical sticks, hence 4...
IF it works, and that's the biggest concern, it would run at the speed of the slowest DIMM. truth be told, it's not likely to run at all.

It's not advisable to mix speeds, voltages, brands, or anything else you want to think about when discussing RAM. Stick to a matched set that's been confirmed and tested to work properly together. Otherwise, your outcome isn't guaranteed and is more likely going to result in you having wasted good money.
 
The problem is not just the official timings you see advertised, it is on electrical characteristics and the timings NOT advertised as well..

Even ram dimms with an identical model number from a manufacturer may have slightly different characteristics based on lot to lot variances..

These variances become more problematic the harder the ram is pushed. The memory controller is not always able to compensate.

It MAY work. You may get subtle intermittent errors and BSOD, it may not work at all.

This is why ram is sold in sets. A paired ram set shares electrical characteristics with its paired dimm(s). This is why if you have a bad module in a paired set, the manufacturer wants ALL the dimms back to provide warranty. There is no guarantee a replacement DIMM sent later will be a good match to the others.
 

anaturelover

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Jun 24, 2012
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The problem is not just the official timings you see advertised, it is on electrical characteristics and the timings NOT advertised as well..

Even ram dimms with an identical model number from a manufacturer may have slightly different characteristics based on lot to lot variances..

These variances become more problematic the harder the ram is pushed. The memory controller is not always able to compensate.

It MAY work. You may get subtle intermittent errors and BSOD, it may not work at all.

This is why ram is sold in sets. A paired ram set shares electrical characteristics with its paired dimm(s). This is why if you have a bad module in a paired set, the manufacturer wants ALL the dimms back to provide warranty. There is no guarantee a replacement DIMM sent later will be a good match to the others.
ok so
even lets say if i find same brand same timing 4th stick of 4 or 8 g it would not work well with the 3 first because they are not part of the same production batch? is that exact?
 
It MAY work without problems. No guarantees. You normally see only 4 timing parameters and a frequency posted for any particular RAM model. There are many more than that in Primary, secondary, and tertiary levels.

The 4 you normally see are the primary CAS Latency, tRCD, tRP, & tRAS
These would be the ones you see adjustable in a simple BIOS for example: 16-16-16-32 2T

Secondary timings would include tWR, tRFC, tRDD_L, tRDD_S, tWTR_L, tWTR_S, tRTP, tFAW, and tCWL
SOME motherboards expose these timings to tweaking as well, many won't of course for good reason.

Then you can get into the tertiary layer.

Your memory controller has to be able to synchronize all of that, which can be hard enough for 4 identical sticks, hence 4 DIMMS usually not being able to be clocked as fast as two DIMMS.

Memory from any particular maker may have advertised Primary settings which are the same, but these are co-dependent on other electrical characteristics of the RAM, which can subtly vary from chip to chip and lot to lot, even for chips sourced from the SAME chip manufacturer. Your DRAM maker may use Micron chips for 1 model, Hynix for another, etc,

Memory best bought in a matched kit for best compatibility.
 
Solution