The QVL and You

So I'm wondering if anyone could explain or point me to an article which answers this basic question, "How come some memory doesn't work in some computers?"

Take, for example, a Dell laptop. Some memory brands will not work when installed. Is this because the motherboard manufacturer is responsible for finding compatibility with certain memory modules? Or do the RAM companies and the motherboard companies come together at some point? And how can Crucial Memory Inc. guarantee 100% compatibility? Are they using very generic/compatible modules on their DIMMS that are recognized across the board by computer hardware?

I mean, I remember buying a brand new ASUS motherboard and the first release of some OCZ memory and it ended up being incompatible. However, after some time had passed, and I believe the memory was updated to "Revision 2", it is now compatible in that motherboard. So at the end of the day, how is memory compatibility dictated? Is it on the motherboard mfg'ers end? The memory mfg'ers end? Or is a joint effort?

If anyone could refer to the Dell scenario I mentioned, that'd be most appreciated. Is Dell manufacturing their hardware to recognize a very limited variety of aftermarket memory modules?
11 answers Last reply
More about tomshardware
  1. Not really sure myself why some memories wouldn't work on other boards, when in fact they're all just friggin RAM. Though I do know that not all RAM modules are made the same, different manufacturers have different quality of materials and quality control. Mobo manufacturers and RAM makers make a compatibility list, I guess by actually sticking in the RAM into the board and testing the hell out of the thing.

    I think it's not intentional on Dell's part to limit compatibility, but rather on the ones that manufacture the board and RAM that they use. It's a fuzzy topic for me, and I've learned to accept that there really are incompatible components when put together. It's really one of those things that the consumer has no control over, and that the manufacturer has tried to do their best. I just learned that I need to do my research before buying certain parts that I'd like to use.

    For laptops, it's really Dell's fault for choosing a mobo with incompatibility with some brands, but I guess if they always did choose the best parts then a good $1000+ laptops would be non-existent.
  2. Thanks for the response. Any other thoughts?
  3. I think memory Mfg.'s like Crucial for example test most Mb's for cpmpatibility with their RAM. Crucial has a memory configurator like this one. Just put in your MB info. On the other hand, MB Mfg.'x like ASUS for example only test the major RAM 'Mfg's' like Micron for example as opppsed to every RAM company like PNY, Patriot, GEIL, etc. To answer you question directly, depends on the MB chipset and RAM specifications, voltage, SPID, etc. Usually company's like Crucial (Micron) list HP, Dell, etc. compatibility on their 'Advisor tool'.

    http://www.crucial.com/index.aspx?gclid=cnio86ls7jecfqwcawodfcxpxa
  4. ^Agreed. Add to the list:

    Corsair
    OCZ
    Kingston
    G.Skill
    ^Those are all good manufacturers.
  5. badge said:
    I think memory Mfg.'s like Crucial for example test most Mb's for cpmpatibility with their RAM. Crucial has a memory configurator like this one. Just put in your MB info. On the other hand, MB Mfg.'x like ASUS for example only test the major RAM 'Mfg's' like Micron for example as opppsed to every RAM company like PNY, Patriot, GEIL, etc. To answer you question directly, depends on the MB chipset and RAM specifications, voltage, SPID, etc. Usually company's like Crucial (Micron) list HP, Dell, etc. compatibility on their 'Advisor tool'.

    http://www.crucial.com/index.aspx?gclid=cnio86ls7jecfqwcawodfcxpxa


    But really that's no explanation at all. What does "testing for compatibility" involve? Sticking the DIMM in a slot and seeing if the computer will POST? Ok, so if it doesn't POST they just scratch Brand X off the QVL? Sounds like cave man tactics.

    And don't you mean SPD instead of SPID? How that plays into compatibility with motherboards is not something I'm seeing here. The SPD just allows the motherboard's memory controller to set certain parameters on its own, such as latency timings, without requiring user input. And it's not like there's an astronomical variance among RAM voltages. It's not like some DIMMS require 5v while others 1.8v. Again, unless your MB cannot provide 2.1+ volts, I don't see how voltages play a large role in determining compatibility.

    I'm interested in learning how compatibility is developed, and why incompatibility, in the case with Dell laptops for example, is especially developed or overlooked.

    Is the software of the BIOS the determinant factor? So memory manufacturer's aren't the ones who need to be concerned with compatibility, only the MB manufacturers? Could someone who knows provide some insight please?


    Anonymous said:
    ^Agreed. Add to the list:

    Corsair
    OCZ
    Kingston
    G.Skill
    ^Those are all good manufacturers.


    That's not the point of this thread at all. Try reading the whole thread before posting next time.
  6. Quote:
    I'm interested in learning how compatibility is developed, and why incompatibility, in the case with Dell laptops for example, is especially developed or overlooked.


    Can you adjust the voltage on a DELL? Certainly if a DIMM required say 2.0-2.1v to run at advertised speeds and the DELL was set at 1.9v, that DIMM would not be compatible with a DELL. As far as a company 'fixing' their machines to run on 'their' RAM or RAM they sell and suggest, that BS. You should know better. Put your DELL or whatever Mfg's system in any memory company's Configurator and all the 'guaranteed for life' DIMMS you can swallow will come up.


    What are you talking about when you say, "the specifications of the RAM (voltage, SPID, speed, etc.) and the BIOS limitations put forth by the system builder and the MB itself have nothing to do with it (which RAM is compatible with the system). Specifications of the hardware have nothing to do with compatibility? RAM is even backwards compatible for gawd sakes!


    http://crucial.com/

    http://www.kingston.com/

    http://www.corsair.com/
  7. Quote:
    If anyone could refer to the Dell scenario I mentioned, that'd be most appreciated. Is Dell manufacturing their hardware to recognize a very limited variety of aftermarket memory modules?

    A motherboard bios can be programed to look for a tag on the ram.
    Without that tag, the computer will not complete post.
    Dell may set those paramiters because they realize that the better the quality of the ram, the fewer the problems you the user may have.
    Then again, they could have an exclusivity deal with one or more manus, and as a result get thier ram at a lower price.
  8. Quote:
    Could someone who knows provide some insight please?



    http://www.answermejesus.com/ask.asp
  9. badge said:
    Quote:
    Could someone who knows provide some insight please?



    http://www.answermejesus.com/ask.asp


    lol. thats mean
  10. endyen said:
    Quote:
    If anyone could refer to the Dell scenario I mentioned, that'd be most appreciated. Is Dell manufacturing their hardware to recognize a very limited variety of aftermarket memory modules?

    A motherboard bios can be programed to look for a tag on the ram.
    Without that tag, the computer will not complete post.
    Dell may set those paramiters because they realize that the better the quality of the ram, the fewer the problems you the user may have.
    Then again, they could have an exclusivity deal with one or more manus, and as a result get thier ram at a lower price.


    Thanks a lot for the response. So whoever programs the BIOS must include information about the DIMMS in order for the computer to detect them and POST? So is this "tag" memory manufacturer's use to identify their memory via the BIOS derived from a universal standard? Or would individual company's (Corsair, mushkin, etc.) each have their own unique set of "tags"? And thus, the mobo guys would need to get those "tags" in order for compatibility be reached?
  11. I really like Corsair, they have never failed me.
Ask a new question

Read More

CPUs Compatibility Motherboards Memory