[SOLVED] DRAM/mobo compatibility (a general question)

[jhsachs]

I have always thought that DRAM/motherboard compatibility is not a big deal. If a DRAM stick is the right DDR type and has the right number of pins, and isn't something weird like parity memory, it works. Furthermore, as long as it is fast enough not to limit the speed of the board, one stick works pretty much like another. I know memory timings also affect performance, but it seems to me that those differences must be small. Different DRAMs use different voltages, but as far as I know, any motherboard will adjust its voltage automatically.

But lately I've been studying motherboard specs, and I see that many of them have lists of compatible brands and models of DRAM. How important is this? Are the board makers just trying to avoid having to diagnose some wacko DRAM maker's problems, or is are there practical reasons to use only memory sticks that have been "blessed"?

 

[boju]

This will be right up your alley. It's old but most if not all of it is still relevant.

https://www.tomshardware.com/reviews/ddr-dram-myths,4155.html

And ram troubleshooting and advice if interested.

How To - Troubleshooting problems with PC memory (RAM) and XMP profile configurations

In the beginning, there was......BIOS Before you go ANY further, go to the manufacturer product page for your specific motherboard model AND revision. Revision is an important aspect because for any given motherboard there may be more than one version of that model which will be identified...

forums.tomshardware.com

 

[jhsachs]

Good source, boju. For people who shy away from reading more than a brief post, I'll repeat the essential part:

"Usually, I suggest checking with the DRAM manufacturers.... The motherboard manufacturers provide a qualified vendors list..., but it usually consists only of the small variety of DRAM they have available in their labs and isn’t as reliable as checking directly with the DRAM manufacturers."

 

[boju]

"Usually, I suggest checking with the DRAM manufacturers.... The motherboard manufacturers provide a qualified vendors list..., but it usually consists only of the small variety of DRAM they have available in their labs and isn’t as reliable as checking directly with the DRAM manufacturers."

Sorry. a lot of that info is in those links and thought you'd be interested in it, you did say study after all ;P

Yeah okay so, QVL is a good start but not necessary. If you want a level of assurance, best go with QVL or other verification. There's hundreds and hundreds and hundreds of different ram brands+models of varying capacities and speeds, mobo manufacturers just don't have the time to test them all. What is on the list is what they've managed to test.

Dram manufacturers do more testing of their own, but for all motherboards? I'm not sure. Potentially you have two sources of info to go on when choosing ram, motherboard manufacturer and if a ram set isn't on the QVL list then check the Dram manufacturer for their compatibility list.

 

[boju]

There's also varying IC chips used on memory PCB too. Micron, Hynix and Samsung to name a few. Samsung are the leaders when it comes to IC chips. Usually ram from say Gskill, Corsair etc, the lowest Cas timing ram usually use Samsung Bdie. Samsung based ram do cost more though, but good ram they are.

 

[jhsachs]

Another word about this: I discovered that the DRAM manufacturers' compatibility lists are not as helpful as I thought. It's an excellent suggestion to check them, and I appreciate it, but while motherboard manufacturers typically publish specs for discontinued products, including RAM compatibility lists, DRAM manufacturers generally publish only for current production products. If you want to buy used RAM or reuse RAM from your spare-parts box (both apply to me) you're limited to what the mobo manufacturers provide.