I've had problems with Crucial memory, and I won't buy their memory unless it's what Apple sells. I've talked to various people at Apple about RAM and they've all told me that Apple's memory is tested to ensure longer life.
Here's an example of what happens.
Let's say you run a RAM module in a test and it does 10 passes. the memory might test perfectly with no errors, but when you run the same memory through 100 passes, it might come up with a couple of errors. So a lot of the 3rd party stuff that comes on the market might not pass the 100 pass test, but it passes the 10 pass test. What does that mean? It means it's flakier memory and it's probably going to fail sooner than the other memory.
IF you go to Amazon and start surveying various 3rd party memory kits for Apple, look at the reviews, there are some kits where there are people that got memory that was DOA or incompatible, and in some cases the negative reviews were almost as much as the positive reviews.
The fact is that going with 3rd party memory is a much more riskier proposition and for some of us, it's not cheaper in the long run. It's more of being shortsighted. I would never recommend 3rd party memory for a computer that's under warranty or under a Mfg service contract because they won't be able to swap out the 3rd party memory and it's more of a pain in the rear swapping out memory to trouble shoot a problem since the AHT does typically work with 3rd party components, so it tells you to use Apple memory. (At least that's what it's done in earlier versions of AHT/Diag). I haven't run it with 3rd party memory lately, but that's how the older versions ran.
I understand Apple charges more for RAM upgrades and they have dropped memory prices every so often, but they don't respond to the open market as quickly because they simply aren't set up like a typical memory reseller, they buy their memory on contract and they don't always pay cheaper prices due to their testing requirements. Most top tier mfg don't drop memory prices as fast as the 3rd party crowd, they just aren't set up to do that.
It's like buying car parts from the mfg or the 3rd party parts. If you want the name brand/genuine parts, they cost more, same principal.
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Here's a link to a customer's comment on Crucial's User Forum. It kind of backs up what I've been saying. Trust me, 3rd party memory is a crap shoot.
http://forum.crucial.com/t5/Crucial...ade-not-working/m-p/51816/highlight/true#M926